DYNAMICS 001  BEAM 

I liked the idea of using Toons when we did it in class and wanted to see what this might do. The though is to shape the cylinder along the lines of when the spacecraft doors open and the beans would spread out at the same time then falling to the ground. I have done a rough shaped of the cylinder as a test and used the polyDisc to move to the ground with the particles emitting as the disc animates over the cylinder. It is  bit hard to see the few particles in this slide, I like the way the particles are creating another layer of texture around and out side the beam. Again I have kept the settings basic to see how it might look.

Emitting particles from an ep curve with Directional emitting from the edit points, direction Y -1 and Emission Speed Attributes, speed 10.  I then looked at doing a circular curve at the base of the cylinder geometry (my standby space craft) and controlling the number of beams from the curve’s edit points.

Here I set the streaks that are being emitted from the ep curves edit points as the lead particles and created a follow omni emitter, with the MultiPoint option in Particle Render Type,  rate of 100. Turned off collide on the follow particles and can adjust the width with Multi Radius under Shading.

Using a single omni emitter set in the cylinder geometry, 10 particles/second, emission speed 1 the beams were directed to the edge loops on the torus. Particle: Live forever, conserve 9.5, dray 0, Particle Render Type streaks, Line Width 10, Tail Size 1. Under Goal Weight and Objects the Goal Smoothness  and TorusShape1 gives me options to create either the straight beams or the circular motions.  Goal Smoothness at 3.6 and TorusShape1 at 0.15 gives me a broken line and it is more flowing and circular motion. Using a volume emitter, Torus gave me access to the Volume Sweep and Section Radius.

At this point I would like to look at how I might be able to create a more solid, semi-transparent shapes for both the main tractor beam and to add variety to the area around the beam. The other thought is how to create texture with a variety of size, opacity and density.

testComp Video:  password – dynamicsFirstTest108

Refining the ideas:

Starting to working on the idea of sparkles when the space ship door opens to send out the tractor beam to pick up the character.

Using nParticles I started with Goal Weights to take on the form of the polyDisk and was not able to get it to work how I wanted. I had done some tests using a curve and this did not give me the sense that the cap was full of sparkling type movements.  Then I looked at using emit from Surface for the particles and did some tests to see how the emitter worked and how the particles could look. I was attempting to get a random, sparkling effect across the opening before the tractor beam comes out. Initially the particles were still falling from the geometry, turned off the Ignore Solver Wind and Geometry and then adjusted the values on the emitter. I chose points, emit from surface so they would cover the surface and not be from the geo’s vertex.

Adjusting the values after awhile I realised the normals were facing the wrong way, I rotated the polyDisk though could have changed the normals direction.  I put the Speed to 0.5, Speed Random to 1, Tangent Speed (not just emitting in the direction of the normal) 0.5, Normal Speed (controls the magnitude or strength of the velocity) 0.5. Using both the speed and normal speed to give some depth with the particles not completely flat on the surface. Then the tangent speed and speed random added some randomness to the emission. Particles do not understand how to behave in the atmosphere how we are used to experiencing our world and all these attributes and values need to be assigned. At the moment the rate is 800 and I am happy with how that is covering the surface. I have put a max distance of 0.3, the min and max distance control how far from the emitter the particles are created, giving some depth to the surface particles.

I need to control when the particles stop so they are not live and continue to be emitted when the space craft moves off.  On the ParticleShape node I have used Random Range for the LifeSpan setting it to a LifeSpan of 5, Random 5 and General Seed to 2. The idea is to add to the randomness  created by having the particles live random amounts of time with the General Seed randomising how the lifespan random is distributed amongst the particles.

Adding to this and creating a more sparkling effect I have added a per particle colour attribute and used a ramp to vary the colour during the life of the particle. The point size is 3, too large made it look like a solid coloured slab. This is working for the initial idea of sparkling colour appearing when the space craft hovers before sending out the tractor beam and also while the tractor beam is operational.

Now I will look at setting up the beam and see how they work together.

I have created a tapered cylinder for the tractor beam and animated the black and white texture values to control the surface emissions. The grey scale ramp has been mapped into the Texture Rate attribute of the emitter.  It uses the black (0) value, no particles emitted and white (1) values with the totally rate set on the emitter to control when and where the particles are emitted.  As it is a multiplier the emission rate is multiplied by the colour value in ramp with the grey values adding more variety and control. I like the option to be able to change the geometry’s shape, and animate the toon geometry that was created in order to make adjustments to the particles.

Using a V ramp, right hand side of the ramp is the top of the cylinder and interpolation set to smooth which is a bell curve blending quickly to the next colour. This could be adjusted with none being more like bands. There is a Noise attribute giving offsets from the U and V directions which I have not used at this stage. I have used the toon idea from my experiments to add variety outside the beam. There were originally two distinct shapes and I have scaled the toon geometry to be closer to the other geo shape. I also liked the idea I worked on with the particles being goaled to an animated torus shape that was looking around for the character. I will add these and see how they work together.  Have not use gravity or wind attributed on the nParticle to move the particles.

Here I am looking at creating the beam of light using a CV curve as a motion path for the sphere. I have chosen cloud for the particle type and looking at what type of emitter.  I think it is going to be a directional on and will look at keyframing the direction to change from the down to the up movement.  With directional I have the direction x, y, z available on the emitter but the particles are emitting from the vertex.

For the line shape beams I was decided to go with motion tracking instead of goal weights to an animated shape. I had trouble working out how to have the CV curve positions so it looked like the the shape moving along the curve was in the right place. Also how to have the beams go down and then come back up, hello, put a u turn in the curve, why does it need to stop at the bottom.  I have a working cylinder set up between the space craft opening and the character and when making the curve I eventually worked out to snapped the points to it to position curve line shape look thus looking like it belongs as part of the sparkling beam.  It is a Directional emitter with 1 in the y direction, life span is constant at 10, particle Radius at 10 and the Radius Scale tapers off for the tail.

Under Shading the Opacity ramp has been adjusted from about half way at the beginning to full a third of the way and tapering to zero at the end.  Now how do I control when the particles start and finish. Finally I worked it out, I can set key frames for the U Value on the motion path to control when the movement starts and stops, will now look at adjusting the speed along the motion path like when it leaves the bottom and the twisting.  I am still having problems working out why and controlling when the particles turn on the motion path. I am thinking it might have something to do with the direction of x, y, z in world, local or object space when I set up the motion path. Still working on that.

I need to look at a few things like adding depth sort, including more random attributes such as particle size (link radius scale age to randomised ID p13), fields, maybe a Newton field, having particles collide with each other using force fields or particles emitting particles. I’m not sure about the horizontal streaks in the long line particles beams. I’d like to work more on creating bursts of particles by maybe key framing the rate or key frame goal weight and goal smoothness.

Rendering

Chris, I need help with the rendering side of this and have not worked out about using the back plate and compositing in Nuke. I rendered out the whole scene, thanks for the heads up about leaving a week for rendering. I stopped working on the particles on Wednesday of the second week of the break and started rendering. The first render went from Wednesday evening and by the week-end it was still going so I stopped and rethought it all. The up side of this is that I re-read the class notes and found this very helpful. It was suggested I change the render setting quality from 1 to .25 which I did and picked up where the first render had stopped. I realise that I needed to cache the particles when splitting up the render like this and due to being a bit stressed about time and not really feeling like the particles were looking very good I wanted to at least have a render to hand in. I have supplied a playblast and I think there is too big a difference between this and the render. There is a problem with the colour of the particles and I need to work on the transparency/opacity issue. For some reason I thought I did not need a PSI node for nParticles and not sure if this is the issue, I need to look at it.

The other thing that I would like to have done more of is go back to your video about the brief while I was doing the particles. I looked at it again after the render and feel there are a few things that could be worked on and added to the particles. This would look at some breaking up of the particles  with differences in the variety in the colour, texture, rate, opacity and size; like the ribbon effect you mentioned and some finer detail for contrast and depth. Maybe when I brought the two cylinder geometry shapes closer together I could move them apart again and work on the differences.  I like the sparkles, it does look a bit different but at the expense of probably not having enough of the cloud and vapour like appearance adding to the sense of motion. I like how the dots move down and the graduation as they move give gives a sense of motion,  again maybe some more variance.  I changed the circular ring motion on one of the cylinder shapes for a more bended movement as they move and thinking about it the circular motion might have created a great sense of movement, randomness and contrast. I have not managed to build the wispy trails with some scatter disappating in the atmosphere that you spoke about or the smoke, vapour or mist feeling.  The line type beam particles also need more variance and changes in intensity and maybe this is where I could have a stronger sense of changes in colour like when you spoke about the heat intensity of the beam. Maybe a couple of these longer beams could be the ones to introduce the wispy tails and the cylinder shapes have more of the cloud or vapour effect.

Assessment 1 (b):  Process Diary – week 15

Taking the tractor beam simulation from part (a) in week 9 with feedback and further research develop and take the dynamics further

Some of the problems I had working towards the week 9 assessment have been sorted out including the position of the ufo camera in my scene. The focal length has now been set to 27.0.  I was not able to get the perspective camera happening which caused a bit of stress. There is also the option to reset cameras by selecting it > look through the camera > view > default view or dragging the perspective camera into the viewport.

General Feedback

– how does the tractor beam work, the mechanics of it and how the elements work together when combined. Why are the particles doing what they are doing

Tractor beams use light to move objects, like a blast of water.  The light beams exerts a tiny force of light, a forward push when it hits something or it can also pull.

This force comes about because the electric and magnetic fields in the light polarize the material in the object, and the polarized object can then reduce its energy by moving to where the light is most intense.

By adjusting the material properties of the object and the polarizations and synchronization of the individual light waves in the beam, physicists can make the object radiate more light forward along the beam than backward toward its source. The radiated light then acts like a reverse thruster, overcoming the already-reduced forward push of the beam and driving the object back toward its source.

Not Pulling Your Leg: Tractor Beams May Be Possible

…it draws an object toward it without making physical contact. “By shaping a beam of energy so that it goes around an object in some way, hitting it in the back, it’s possible to then pull the object instead of push it.”

Researchers Achieve Better Illumination of Biological Samples – Publication in Nature Communications

Optical Tractor Beam Sorts Tiny Particles

– what parts of the reference image is relevant, break it down and think about what I am attempting to design. Talk about it and create my own concept art to help make my imagination a reality

– what is it about existing tractor beams that would make the audience feel comfortable

When I first looked at the tractor beam I initially focused on more traditional ideas, then I started exploring alternative images while considering the tractor beam being a non-threatening experience. I went back to my drawings and looked for more references.

The Gardens by the Bay in Singapore light show images reflect happy, fun time and are something different.

– add something to create extra movement, possible lines that run down the outside of the outer cone then spray fine misty type particles, they could be thin circles or tubes that move down the cone from the ufo

From these different drawings I continued focusing on the sparking idea as this reminds me of happy times like Christmas and party time lights. I’m considering the ideas of the traditional tractor beams and how they work using circles of light together with the sparkles for particles. With the spiral, tendril not working and deleting the idea as suggested I’m now focusing on how to create movement with the moving circles and how this will work with the sparkles.

– consider these attributes: Mass on Particles – which can give subtle variety of movement, Conserve –  can add further variety of movement with small changes having big effects, Oversamples – in the Solvers Menu and may help with gaps in the particles and will make the simulation slower, Lifespan, varying it on the particles to add variance to movement and form, Fields – could make more use of this in having the particles moving, Depth Sort – if not using show that it has been considered, also consider Lighting and Colour Accum etc.

I have used the ramp in Mass Scale for two of the particle systems to vary the mass which determines the density or the weight of the nParticle, a lower Mass value and they will mover faster.

I have left conserve at 1 which influences the particle object’s velocity from frame to frame with 1 they will not lose any energy.

The oversamples are at the default value.  Specifies the number of sub-steps for each frame of your dynamics simulation. A value of 1 sets no oversampling. A value of greater than 1 causes Maya to oversample your dynamics simulations by the specified value. You can use any arbitrary value for Over Samples, as long as it is a positive integer.  You can often fix excessive dynamics behavior by increasing the oversampling of your dynamic calculations. Increasing oversampling slows down playback but increases the stability of your dynamics.

The Lifespan for two of the opening of the UFO and the inner core are Random Range to add to the sparkling effect and the outer core beam has a Constant value of 0.1 so it looks more like the moving circle and the particles are more attached to the shape.

For the Fields I have introduced a Gravity Field for the inner core beam as I found it slightly changed the shape of the points in a random way, not so round. The field does not have a large impact on the actual movement as it is a surface emitter, I like the subtle change it has caused in the particle shape and I think it helps with the flickering.

I have turned on Depth Sort for rendering which sorts the particles based on their depth from the camera, Colour Accum which allows overlapping particles to influence the colour of each other.

– shadows for the mannequin for rendering, possibly light from the tractor beam to light the mannequin and talk about it. The mannequin is reacting to the light of the tractor beam and feels like it is inside it.

I have created a shadow pass for the mannequin to be used for the Nuke compile. For the tractor beam a glow on the beam in Nuke works much better than I would be able to create in Maya.

– reflections and ambient light, are the particles visible in the UFO

I did not like the idea of the particles being visible inside the UFO, as the particle’s purpose is to focus on the mannequin and to relate to it being lifted up into the UFO. Actually I think you might be speaking about seeing the particles on the surface of the ufo. This would possibly look great though have not gone down this path at this stage.

Things for me to work on

– explain more what parts of my reference images are relevant and what I would like to incorporate

While I was looking through references and drawing the shapes I started to notice some of the qualities regularly used as part of tractor beams such as lines and swirling shapes. Parts of the images had sparking qualities and as I have mentioned in the general feedback I began to focus more on this area of possibilities.

– talk about when using certain techniques I am able to create a simulation that looks like the images gathered  

After using several different render types each time it came back to points when looking for ways to make them sparkle.

For the particles at the opening of the UFO’s the geometry emitting particles is now positioned at the UFO’s opening thanks to the perspective view, called opening in the outliner. They make the opening more obvious when introducing the particles here, revealing them as the hatch door opens. It is a surface emitter defining this shape without much movement from the surface. TheBasic Emission Speed Attributes of Speed 1, Speed Random 1, Tangent Speed 0.5 and Normal Speed of 0.5. This worked better as a polyDisc instead of a curve for the opening shape to be able to fill the space with particles.

To create some interest with contrast and movement I have put black and white values into the emitters Texture Rate and a colour ramp in the particle’s RGB PP.  I have added more colours and lightened them to fit in more with the colours of the other particles while leaving them darker than the others. This works for keeping them the same but different from the other particles and adds to the perspective depth between the particles and area of focus.  Radius is 0.2 to keep them small with 0.5 for Radius Scale Randomize and included some opacity with the Opacity Scale.

– more detail in the movement, more particles the particle count will help add detail, the tractor beam is hard to see and needs to feel more like a light source 

There are two other emitters, the first one is a surface emitter called innerCone and the second is a toon emitter acting as another tractor beam or outerCone.

Working on the inner cone first, I’ve make this smaller to see the difference between the two beams more clearly and build some variety. The geometry is tapered more from the UFO opening to the mannequin, making it not so symmetrical, a surface emitter with Particle Render Type as Points.

Staying with the sparkles, firstly increasing the number of particles, the particle count to 30000 making a more defined shape and a speed of 0 for them to stick to the surface.  There is not enough change happening in the position of the particles, Radius is 0.2, Radius Scale Randomize is 0.2, using the ramp on Mass Scale and Opacity. It was still looking too solid and no movement in the shape.

Going back to the Texture Ramp, on the emitter, to see how I can introduce and control more randomness with the particle placement and how the shape is appearing has been interesting. I looked at what might work by adding more black and white points on the ramp and adjusting the gradient with these values. Emitting particles from the white areas and the grey scale is a multiplier for the rate set on the emitter.  The timing of the particle being emitted now changes more often and more in timing with the idea of sparkles and the black areas are creating some empty areas which I like.

I have also mapped a fractal into the white and black colour selection of the ramp to add more randomness and sparking. This is not working how I had imagined and totally taking away from the down movement and the black and white controlling the particle emission was lost. I took the fractal out of the black and left it in the white adjusting the fractal values to get more control. It is not only the sparkles that has started to happen in areas it is more like the beam is pulsing on and off as it goes down to the mannequin.

Animating the position of the points on the ramp, creating different black and white gradients over the time gave some lovely changes to the particles that were being created. This together with the fractal has added a gentle pulsing  movement and the random placement of the particles leaves spaces along the shape.  I’ve added a gravity field to the innerCore and it gives the points some different shapes.

– likes the sense of an outer cone to the tractor beam, add something to create extra movement, possible lines that run down the outside of the outer cone then spray fine misty type particles, they could be thin circles or tubes that move down the cone from the ufo 

– likes the idea with the cone acting like a ring that moves along the surface of the outer cone to emit particles, revisit what I did with toons in my reference

The outerCone emitter, is MultiStreaks, is a combination of Streak and MultiPoint render types and it displays multiple points with tails for each moving particle. The faster the particles move, the longer the tails.  The inner Cone emitter is points, displays particles as points, although they both look like points I think it gives a subtle difference.

Increasing the particle numbers, lifespan, geometry shape and how it is sitting over the top of the innerCone and creating some rings.

The colour is changing from white to blue as it moves along the beam. Possibly giving the illusion the light’s heat changing and the beam travels. The colour ramp has been reversed and the Input to Normalized Age.

On the emitter I have adjusted the Speed and Tangent Speed to give some direction as the particles are emitted.  Depth sort is on, it is where the particles occlude each other, the render is working out which particles are in from of other particles with the render only displaying the particles it can see.

The start time is 330 and the particle numbers have been increased to 50000.00 and a longer life span. Now I am not sure about the streaks, have put it back to points and the Lifespan from Random Range back to Constant with a Lifespan of 1. The particles are looking more like they belong with the others.  I still have a problem with it appearing a bit flat and not a shape for the mannequin to be pulled up in. I love the circles that are starting to give the beam a sense of movement and some shape. The gap between the the inner and outer core implies that there are two beams and wonder if they were closer if they would get lost with each other. Also wondering how similar or different the colours need to be.

For this outer tractor beam I am using the Toon option which is part of the rendering menu set. Particles will be emitted from the collision point of two objects where Intersecting Lines are enabled. This intersecting line is converted to geometry, pfxToon1 node.  The Mesh now Emits Particles from object and is a Surface Emitter.

Chatting with Chris there is another world out there with want is possible when looking at how to make this a repeating smaller circle that is travelling along the tractor beam shape.

Instead of only animating the movement once, making the animation much faster and repeating it gives the effect that many circles of light are moving down quickly instead of a beam that is streaming down creating longer shapes. In the Graph Editor > Curves > Cycle with Offset and View > Infinity.

Line Width can be adjusted on the pfxToon1 Node and being set to 5.  The emission rate is now 50000 with a start time at 330 frames and the rate is keyframed to 0 later in the simulation to stop the particles being emitted at the end of the tractor beam sequence.

Other options Chris looked at were Duplicate Special for the polyPlane > Input graph option to copy the animation over but this did not seem to work out with the animation in the Graph Editor. Also linking the polyPlane to the correct Nucleus, creating an emitter and selecting a nucleus, using nSolver > assign Solver to Particle, changing the Line Width, connecting emitters and particles.

Reducing the speed (how quickly they move from the emitter) attribute to 0 did not keep the particles on the surface to attempt to give the look like the particles were sticking and keeping the shape. Also the Normal Speed which controls the Magnitude did not appear to be working how I would have thought.

The Key Visibility option for the outerCone_MeshGroup did not change how the particles were emitted. The Lifespan is constant and changed from 4 to 0.1, Radius Scale’s graph goes from 1 to 0, Opacity scale a round curve from 1 to 0, and the colour is similar to the existing beams and Motion Blur enabled.

Chris, thanks working through this.  After having another look at it I like the slightly odd shape of the inner cone as I think it works ok with the random sparkles. I was really excited when I saw them in Nuke and how the background is showing through the spaces in the particles. It brought them alive and gave them more depth. Really shows how I need to see them on the background.

The outer line is sparkling to fit in and having them move faster with a smaller height has a much bigger impact on the overall movement that is happening. It does not get lost with the other particles and takes your attention there. At first I did not like how you could not completly see the mannequin being lifted, now it feels like there is a bit of mystery.  Is that the mannequin you can see moving inside the particles and when the beam goes back into the ufo the mannequin has gone, must have been taken inside the ufo.

I have left the colour lighter, helps create some depth, the space between the beams is showing off the movement and is looking much better than having the longer trail of particles coming down the shape. It is not so much of a blob of particles and gives more interest.

– tendrils are not working, not connecting to the outer cone

This is a geometry moving along a curve motion path with a keyed start time frame in the U Value and particles being emitted from the geo’s vertex points. When I thought the main tractor beams did not have enough depth or perspective I did go back to putting these inside the core beams and having them much finer. They are definitely gone now and with the circles working the way they are this is a much better way of solving this.

– check lifespan set to 1 and random range set to 1 on one

fixed

– remove the ambient light

done

There are some general things I wanted to address including the attributes mentioned in the general feedback.

At the beginning I did not think through some things such as nParticles having different nucleus meaning the particles are not able to collide. I could have used the nCache more which writes the particles to the hard drive in the Image folder of the project. This positions the particle in space for each frame and when using the timeline Maya is not reading other frames to position the particles for each frame on the timeline.

Initially I did not want too many because what happens is when the UFO doors open it is full of particles and I prefer that it looks like it is building up, increasing with the sparkling on and off before the tractor beams start.  I’ve increased the number of particles being emitted (sets the average rate at which particles are emitted per second),  added more variety to the radius scale for subtile randomness, changed to Normalized Age (the per-particle attribute values are mapped within the range of the nParticle object’s lifespan) and changed Lifespan Mode from constant to Random Range (identifies a range of random variation for the lifespan of each particle). Looking at Mass Scale ramp, it is a bit hard to tell how much this is changing the particles as they are not travelling very far, maybe very subtile and adding to the variety, have also set this to Normalized Age. Set the Mass Scale Randomize to 0.5 (Sets a random multiplier for the per-particle attribute values). Turned on Depth Sort and have left the Opacity Scale at Linear, I think this will add to the sparkling effect and input to Normalized Age.

Now to sort out the colour, I have used the Per Particle (Array) Attributes which lets you set the value of the attribute individually for each particle of the object. I am going back to the reference to see what I can do here. I’ve taken out some of the black and introduced some more colour shading.

Rendering

Now doing my rendering in Hardware Rendering, not Software or Mental Ray. Turn off Colour Management (sRGB), padding 4, name.#.ext, render camera, use an image format that supports an alpha channel, select Alpha under the Renderable Camera, Number of Samples which 1 being a hard edge (bit like anti aliasing with more samples giving a softer edge) used 9, enable Geo Mask, possibly Motion Blur, Production Quality, Motion Blur and Frame BufferRGBA: 16-bit float per channel. Do not need the option box for Batch Render as the Render Settings does this.

One of the problems was with rendering the particle’s colour, I’ve stopped using Mental Ray and staying with Hardware Rendering. Now that has  sorted my colours, they are consistent and I am more confident when choosing colours.

Can create a cache, nCache > create new cache and make sure the project is set and the cache goes to the projects Images folder.

Render > Batch Render and do not use option box because the setting have been set up in the Render Settings, Maya Hardware options.

In Mental Ray it converts particles to geometry.  The streaks tails need a transparency on the shader to fade the particles from head to tail. There is a connection with opacity, transparency and the alpha channel.

For the Toon have the Render Stats > Primary Visibility> off.

http://help.autodesk.com/view/MAYAUL/2015/ENU/?guid=Particles__Create_Emitter

http://download.autodesk.com/global/docs/maya2014/en_us/

 Baking Dynamics

I had problems with the scale of the dynamic mannequin. With Chris’s suggestions the solution turned out to be to bake the simulation. I did this by selecting the translate and rotation values in the channel box. This was not enough, when I scaled the mannequin the constraints were still there, full size and only some of the geometry was scaled. I needed to select all the geometry when baking and then deleted the constraints from the outliner and the scale to 0.5 worked fine.  When I was scaling the geometry without baking the simulation the constraints were not scaling with the geometry.

Baking converts the dynamic induced animation to keyframed animation and the animation curves can then be tweaked and manipulated like all other animation curves. It is like caching particles so when played it is already keyed and if the dynamics break all the keyframes are there.

Remember when importing if it has been referenced then import from the Reference Editor > Right Click > File > Import Objects from Reference.

Heat Plume

Starting with nParticles like we did for the basic smoke trail in week 5, using a volume emitter, adjusting the volume emitter with a  shape cube, scaling and positioning it inside one of the exhaust vents.

Keyframed the emission rate (particles/sec) on the emitter from 0 to 2000 and animated the emitter as the UFO moves away. Looking at the following attributes I set the Along Axis, Away from Central Axis, LifeSpan to Random Range (3, 2), Particle Size (3), Normalized Age, Depth Sort, enabled Ignore Solver Gravity, Threshold (0.5), Opacity (0.98), Directional Speed (10), and looked at collision friction and sticky.

Then I used the particleCloud shader and connected the PSI and reverse node to work out the opacity and transparency, rendering in Maya Software. Not happening. Below is a list of screen shots for what did not work, learnt a lot.

The choice of the nDynamic particles of thick cloud was not the way to go. There are presets in the Maya nDynamic system with this option and it was difficult to know and control. There was no need to add another particleCloud shader and this doubled the problem so to speak and the default one was the one to go with.

After much checking with Chris it is back to the drawing board and going with what we did in class, week 7 for particle distortion and going through the notes. So here goes.

TAKE  TWO, probably a few more than that – heat haze for the UFO

– create nParticles: points

– volume emitter shape: cube, scaled and positioned in one of the vents of the UFO.

– particle render type: blobby surface (s/w)

– added a blinn to the particles and made the colour black, transparency white, diffuse 0, reflectivity 0.

The Rate (particles/sec) has been keyframes from 0 to 250 to 1000 from the first frame to frame 139. Giving me a more of a sold look and a rippling surface.

Initially had trouble seeing the particles and the radius was too small, made 30. Lifespan is Random Range with 2 and 3. Depth Sort is on, Threshold is 0.5 allowing par tiles to merge with 0 having no merging.

Threshold: Determines the smoothness of the surface created by overlapping Blobby Surface nParticles. Threshold is based on the overall density of overlapping nParticles. Each nParticle has a density of 1 at its center, which then falls off to a value of 0 at the nParticle’s edge.

To see how this might look in Nuke I need to only render out the particles, everything gets turned off and a surface shader is used for the geometry of the UFO. There is a heat haze happening with the iDistort node and a Copy node to use the UV channels to apply greyscale values across the image. Have also added a blur node.

Now I want to apply this to all the vents of the UFO and also need to adjust the contrast values of my particles.

I am duplicating the emitter, then selecting the particles and under nParticles > Use Selected Emitter. I now have particles in each of the vents. I then parented the heatHaze emitters to the geometry and they will follow the UFO across the scene.

Another option was to create a locator, put the pivot point of the emitter on the locator with the emitter positioned at the vents and the locator parented to the spaceship.  The animated keyframes for the rate can now be positioned for each of the emitter’s rates. I needed to make one keyframe on each emitter’s rate then was able to past the original keyframes and position them on the right frame.

Making the UFO geometry a passive collider means the heat plume particles will not affect it. In the make passive collider option box choose the solver related to the relevant particles.

When nParticles collide with passive collision objects, their behavior, speed, and direction change. Passive collision objects are not affected by collisions with other objects. 

I am not sure about the reason for this as I rendered the particles on their own and used that in Nuke to create the heat haze effect with the iDistort node.

Re-rendering these particles and seeing how it basically works in Nuke against the back place I have heat haze distortion happening. Now I have this basic workflow set up I would like to do a lot more with the particle attributes such as having more control over the black and white values, the size and shape of the particles and how the move when the vents open and the UFO moves out of the scene. I will hopefully have time to come back and look at this. Chris thanks for your class notes they are amazingly helpful and help form some great class mates.

Would consider looking at:

Away From Center:  Specifies the speed at which particles move away from the center point of cube or sphere volumes.

Along Axis: Specifies the speed at which particles move along the central axis of all volumes. The central axis is defined as positive-Y for cube and sphere volumes.

Directional Speed:  Adds speed in the direction specified by the Direction XYZ attributes of all volume emitters.

Some things I was using previously that were not appropriate:

Self Collide:  When on, particles generated by the nParticle object collide with each other. When off, these particles do not collide with each other.  Which means I do not need to use the friction and stickiness.

Emission Overlap Pruning:  Removes newly emitted nParticles before they appear in the simulation based how much they will overlap with existing nParticles. This value scales the collision radius used to determine overlap. A value of 1.0 it guarantees no self collisions with other particles on emission.

Notes – autodesk help files

Link to:  Basic Emitter Attributes

MAYA HELP nParticles Shape Node link

nParticleShape

Particles Emitter

The Brief References

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My References

Stills:

More Recent References

From the Image Peace Tower web site

Gardens by the Bay, Singapore

The stunning forest of giant metal trees at Gardens by the Bay, in Singapore is even more mesmerising at night.  The structures light up in a rhapsody of colours to the sound of music that fills the entire park.  It is  ‘Supertrees’ that make this sound and light performance so impressive, towering above you at up to 50 metres tall.  The show culmination when the trees seem to explode in a firework-like fashion.

Gardens by the Bay, Singapore

The Foundry:  Arriving at Home: DreamWorks Animation on emotions as color, losing gravity, and friendship in the loveable film “Home.”

Shutter Stock: underwater ocean waves ripple and flow with light rays:

http://www.shutterstock.com/video/clip-3703181-stock-footage-underwater-blue-surface-with-rays-of-light-high-definition-p-seamless-loop-slow-motion.html?src=rel/6198947:6

http://www.shutterstock.com/video/clip-6198947-stock-footage-underwater-ocean-waves-ripple-and-flow-with-light-rays-loop.html

http://www.shutterstock.com/video/clip-6198929-stock-footage-underwater-ocean-waves-ripple-and-flow-with-light-rays-loop.html?src=rel/6198947:0/gg

http://www.shutterstock.com/video/clip-5160239-stock-footage-pal-underwater-ocean-waves-ripple-and-flow-with-light-rays-loop.html?src=rel/6198929:9

http://www.shutterstock.com/video/clip-5161661-stock-footage-hd-underwater-ocean-waves-ripple-and-flow-with-light-rays-loop.html?src=rel/5160239:4

http://www.shutterstock.com/video/clip-5161439-stock-footage-ntsc-underwater-ocean-waves-ripple-and-flow-with-light-rays-loop.html?src=rel/5161661:9

Nasa Images Web Page

Video – Youtube:

BULLET maya dynamic plug in

WEEKLY TASKS

I wish I had more time to spend on these, I’ve enjoyed when I have and looking forward to more when I can.

WEEK EIGHT – Rigid Bodies Exercises

I had a lot of fun with this.  Did not get the cube to tumble, it is rotating in Y and I worked on having the ball hit the cube with the cube falling off the edge and the ball stopping before it rolled to the edge. I adjusted the initial velocity on the ball to hit the cube and adjusted the linear damping to stop the ball before rolling off.

Still working on my ball rolling down the stairs. Have not been able to work out how Chris grouped and parented the geometry in the outliner and my ball is not rolling down the stairs. It is still rolling on the shape as thought it was a set to box in Collide Shape Type. I have redone the step geo and created passive rigid bodies a few times. Also adjusting the Collide Shape to Null and the restitution and initial velocity and not able to get this working. Not crying yet, will come back to it now going to look at Winnie the Pooh.

Hello Winnie the Pooh.

Pooh was exploding right from the start, for this to happen on impact

– in Initial State set to sleeping, collision type to Hull and the Wall Body Type on its RigidBodyShape to Static Body

For real world scale set the gravity to -980 on the solver

The cannonBall’s Rigid Body has an initial velocity of -500 in Z to have the ball land as in the screen shot above in the Initial Conditions. Then to land on the other side of the geo instead of falling straight down the Mass needs to be above 1000, I used 1500 giving the ball enough power to go through Pooh and land on the other side of the wall.

Pooh’s pieces are still falling through the ground and adjusting the rate at which the geo moves per frame worked this out. It was still falling through the ground at 120Hz and stopped at 240 Hz.

Using the glue on the Pieces Set Initial State gave me more control over when the pieces broke up on impact.  The threshold value can be used to adjust how strong a force would be needy to break the object. The other issue with this is that the ball is no longer falling on the other side of the wall.

The ground needed some friction to help control the roll and movement of the broken piece, I set it to 0.5.

On the poohFractured_PiecesSetInitialState I set the Linear Damping to 0.3, Angular Damping to 1.0, Friction to 0.5 and Restitution to 0.5. How did they come up with this name ‘Restitution’, like English is short of suitable words?  Glue is set to 70.

The red cannonBall has a mass of 3000 and an Initial Velocity of -250 in Y and -800 in Z.

I had issues with getting all the pieces to fall from the wall and increasing the Initial Velocity in Z too high meant the ball completely missed Pooh. Putting an Initial Value in Y meant the ball would hit Pooh and I adjusted the mass and the glue settings with pieces still staying on the wall. The rotation has stopped when the pieces hit the ground and they no longer roll off the edge due to friction and damping settings.

Now to work on the simulation to go with the scene Anish, Viray, Mat and I set up.  The plate was shot and the geometry measure out with instruction and direction from Chris.

Our idea is to have dominoes falling down the ramp in the quad next to the bike racks creating a pattern on the concrete at the bottom.

WEEK  SIX  Quiz

What is attenuation and what does it do?

A value that sets how much the field’s strength diminishes as distance to the affected object increases, the ability of the field to get weaker the further away the particles are from the field or field decay.  It is the field ability to lose its affect the further away an object is from the source of the field.

For gravity we would probably want them to be affected equally so the attenuation is set to 0 by default or no attenuation. The field will act uniformly or constant across the whole scene.

Maybe for a turbulence field we could set the attenuation to 1 meaning the field will only affect the particles that are close to it. When using high values, objects that are further away will be less affected than objects that are close to the field. Negative numbers are not valid.

Another example we used in class was with streaks looking like rain using a turbulence field. With the attenuation set to 1 the rain is very uniform, when set to 0 the rain appears more random. This is because when set to 1 the turbulence field is only affecting the particles close to it. With the attenuation set to 0 the turbulence field will affect the entire scene uniformly thus causing the particles to look more random.

What is Conserve and what does it do? 

How much velocity is retained from frame to frame, the particle’s ability to conserve its energy.  A value of 1 means it will not lose energy/velocity, it could travel forever and moving constantly.  There are factors such the feeling of gravity, wind and collisions and a typical value is 0.98 and lower values will slow down the particles.  The value is a multiplier that looks at how fast each particle is moving and then looks to see how old the particle is moving and multiplies the age by the speed.

We looked at conserve when using goal weights with lower than standard values. If using 0.8 then the particle headed straight for the sphere without overshooting it. The conserve and goal weight will work together and if they are both to low they may never reach the object they are goaled to.

What function does the geoConnector serve?

We used it when we had exploding rocks, as they hit the ground it controlled how they landed, moved and settled. The geo connector gets made over time when a particle collides with a surface and it controls how the particles behaves when they make contact with the geometry.

On the geoConnector we have an attribute called Resilience.  What does it do? 

The resilience controls how bouncy the surface has.  Higher values mean that the particle will bounce when it impacts.  Lower values will mean the particle bounces less and a value of 0 will stop the particle from bouncing at all.

On the geoConnector we have an attribute called Friction. What does it do? 

This controls how much friction there is between the particle and the surface.  Higher values will prevent the particle from moving along the surface.  Low values will allow the particle to slide along the surface, as if it were on ice or some other slippery surface.

List the steps you need to do to make the particle collide with an object. 

In standard particles select the particles then the geometry, under Particles > make collide.

Select the object  > nMesh > Create Passive  Collider > option box. Choose which nucleus will be used and make collide. This creates an nRigid attribute with it own set of attributes, including the option to disable collide.

If I want particles to inherit the colour of the surface that emits them what do I need to do?

To use the colour from the object emitting the particles for the particles I selected  the particleShape’s attributes in the Attribute Editor. Selecting the Colour Add Per Object Attribute under the Per Particle (Array) Attributes opens the colour values under the Render Attribute’s options. I took the RGB values from the shader and entered them into the Colour Red, Green and Blue here. Now I have a pink sphere and pink particles.

In standard Particles on the emitter under Texture Emissions Attributes I can connect the surface’s colour/texture through the Particle Colour. I create and connect a file node and in its the image name link the file. For the chair this is how I connected the texture tiff file of the chair’s surface to the particles. Make sure to tick the inherit colour. This is how I had the chair’s texture on the particles being emitted from the chair geometry.

In nParticles I added the colour from the surface shader on the object to the particles through the shading attribute under the nParticleShape in the Attribute Editor by selecting the colour under the colour option. For some reason I was unable to select the add Per Object Attribute in the colour option under Per Particle (Array) Attributes for the surface emitter.

On the nParticles emitter there is also a Texture Emission Attribute for mapping in the texture on an object.

What is the difference between a Uniform Field and a Gravity field. There are a few, Chris is looking for one that relates to particles. 

“Gravity does not have an effect on the Mass Attribute, which is located on the particle. This is because all objects, in a vacuum (which is what Maya is), no matter how much they weigh will accelerate at 9.8 meters per second.” page 58, week one.

What happens if I want the weight of an object to be visible in the simulation?

For the Mass of the Particles I need to use a Uniform Field and this has all the same attributes as the Gravity Field. A value higher than one will make them harder to put around and with a value lower than one they will move faster as it requires less force to push it around.

Reference: Christopher French’s weekly class notes.

WEEK SIX   Class Exercise

With a total number of 500 particles from both emitters and have them picked up from one tray and put in the other.

The emitter generates particles, the rate is how many the emitter is making every second or how fast it generates particles. For standard particles there was a Max Count attribute where the total number of particles emitted could be set while leaving the Lifespan Mode set to Life Forever. In nParticles this attribute is in the particleShape under the Emission Attribute, called Max Count. Here I set the number for each particle to 250 giving me a total for the two of 500. The way I can change how long they are generated for is by changing the rate on the emitter. When I set one set the blue particle’s emitter  to 100 on the rate and left the rate on the red particle’s emitter at 250 then the blue ones took longer over time to reach the 250 set in Max Count.

Under the collision attributes of the particles I enabled collide and set the width scale to 1 so the balls collide with each other. This value or one is the radius value of the particle, if less than this they radius will overlap and if larger then the will not touch. I varied the radius of the two particles to 0.4 and 0.5 with the randomise attribute set to 0.2 and 0.3 to make it visually more interesting with different sizes. I also adjusted the ramp in Radius Scale and set to Randomise ID on the radius scale input, this pick a number along the graph and applies the radius.

The trays have been made passive colliders and have an nRigid node. On the landing tray it has some bounce, a little bit of friction and stickiness. The pick up tray has friction set to 0.4, stickness to 0.2 and no bounce. The landing tray has some bounce of 0.2, friction to 0.1 and stickiness to 0.7.

On the particleShape node under Dynamic Attributes I left the Ignore Solver Wind and Gravity un-ticked and did  not adjust the drag. The drag is like conserve on the standard particles where the 1 keeps the velocity constant. If the field are ticked then it is possible to add fields separately.

It is possible to start the simulation with the balls already in the ball pit by setting an initial state under nSolver.

The problem that is unresolved is how to have the balls the stick to the sides and on top of the sides fall into the tray. Still working on the rate at which the 200 balls are emitted so I can have more control over when it happens. The other thing is how do I control how many balls get picked up and how many are left behind.

WEEK  FOUR  Challenge

Waterfalls: Goal Weights and Goal Weights on Deformed Geo

Some References for the waterfall from Getty Images

The geometry has been set up with lots of spans/resolution on the polygon plane due to altering the shape. Deforming the geometry with the texture deformer based is based on the texture mapped into the deformer’s texture attribute. It has been set up with an Ocean Texture and adjusting the

– turbulence

– wave height

 – time expression =frame/20 into the field next to time to change the texture over time

– direction of the water movement is adjusted under Wind UV attributes, not sure how this is looking at the moment and will come back to it

– strength attribute for the height of the waves, 10 and the Offset attribute is set inversely, -10

It is the pivot point of the geometry that gets attached to the particle and they are in the same position. The particles are emitting directly from the geometry, there is no geometry linked to the particles with the Particle Instancer so I will leave the pivot point where it was positioned when the geometry was created. It is not like when we considered the pivot point of the cars that were instanced to particles that were then moving along the ground plane. I will see how this works with the water/particles moving directly across the geometry.

The emitter has been created to emit from object and under particles they are goal to the surface as a surface emitter. For now the Goal Weight has been set to one, with the particles sticking to the surface. When the Goal Weight is zero, the goal doesn’t have effect, this attribute can be animated. From what I can see at 1 the particles are moving with the deformed texture.

The particles are lining up in straight lines along the UV’s. Each vertex is numbered and the particles line up in order, in order to make sure the whole surface is covered  the geometry needs to be normalised. This is checked in the UV texture editor and the surface fits into the 0 to 1 grid.

Under the Per Particle Attributes not all attributes are listed include the goal U & V attributes, add these and the parentV and parentU attributes.  The parent U and parent V attributes are the positions on the surface where the particle are born and it is related to the emitter.  Add the following creation expression influencing where the particles are created, being executed when the particles start to come out.

particleShape1.goalU = parentU;

and particleShape1.goalV – parentV;

The Need Parent U/V attribute needs to be enabled when using surface emissions for Nurbs/poly surfaces and now the particles are scattered all over the surface.

Expression under Per Particle (Array) Attributes, the particles will stick to the surface. When I made this 0.5 then when the particles were emitted they did not stick to the surface, zero would mean there would be no influence when the particles are created.

goalPP = 1;

Creating a Runtime Expression to add or alter the particle’s behaviour on each frame, in the Expression Editor. The Runtime Before Dynamics Expression allows us to make changes to the particle before the dynamics of the scene are calculated, before Fields and Collisions are calculated.  For Runtime After Dynamics the expression will be executed after the dynamics are calculated.  The following expression has been set on the goalPP attribute and says when the particles reach a position more than 0.99 on the texture grid then the goalPP will be zero, meaning there is no influence on the particle sticking to the surface. As the notes say the particles are not moving yet so I cannot see this in action.

if (goalU>0.99)

{

goalPP = 0;

}

WEEK  ONE  Challenge

Make a chair out of particles and have it blow away with either a fan or in the breeze.

I set up the project with settings of 25 fpc, realtime, play every frame, set a larger frame range in the time slider and start at 1:00.  Then scale the chair to  real world scale, maya is in cm and scaled the model by 35 and using the wood veneer texture. The centre point needs to be at origin, modified the centre pivot for the chair then snapped to origin. Now the transforms have an offset so need to freeze transformations.

Creating a surface emitter, using the chair geo as the emitter so the particles emit from it, otherwise they emit from the vertex points. The emitter becomes the child of the chair and travels with it.

I needed to have the chair covered in particles and work out how to blow them away.

What I learnt doing this was to use the Rate (rate/sec) on the emitter to set the number of particles at 5000. The speed is set to 0 so they do not move away. Instead of using the time attributes to start the particles I could already have them covering the chair by setting the initial state under solvers. This was learn’t in later classes and meant I could cancel the ideas I had of turning the visibility off on the chair after the particles had covered them. My chair is invisible from the beginning and already covered in particles from frame one.

The texture is added to the particles on the emitter’s attributes under Texture Emission Attributes.  The file is mapped in on a file node and inherit colour is ticket.

This is where I explored the used of different fields, their attributes and animating the values. I used a combination of air, turbulence and gravity to create different shapes with the particles moving from the chair. I animated the magnitude on the fields, adjusted the attenuation, the directions and animated the magnitude values. I decided to delete the gravity field and changed the airField  to wind. There still needs to be more randomness in the look of the particles breaking up and could look more like they are being blown away by a fan or in a breeze.

Fields are localized or global forces that act on objects. You can simulate the motion of natural forces with dynamics fields.Fields have their own icons in a scene, so it’s easier to select them if you want to animate a field or change its attributes. These fields are included with Maya.

Stand-alone fields influence objects from a stationary or moving position in the workspace. It’s not owned by geometry.

Object Field are owned by an object and exert influence from the object. You can add fields to polygons, Nurbs  curves or surfaces, particle objects, lattices or curves on the surface.

Volume Fields you can select a volume to define the region in space in which particles are affected.

The following  fields are included with Maya:

• Air   An air field simulates the effects of moving air. The objects you connect to the air field accelerate or decelerate so their velocities match that of the air as the animation plays. A “push” type of field, it comes with presets for Wind, Wake, and Fan.
• Drag a field that slows the momentum over time of objects within its reach. A drag field exerts a friction or braking force on an object that’s animated with dynamic motion.
• Gravity  The most commonly used field, it causes objects to move and accelerate in a given direction. You can limit its reach to create localized gravity fields. It simulates the Earth’s gravitational force.
• Newton   Similar to gravity, but operates in a spherical manner. A newton field pulls object towards it. Objects are attracted to Newton fields more strongly depending on their mass and their distance from the Newton field.
• Radial   A radial field pushes objects away or pulls them toward itself, like a magnet. Like the Newton field, but it doesn’t take mass into account. It can be set to diminish with distance, as with the Gravity and Air fields, and it can be set to push or pull.
• Turbulence  Makes the object’s motion or deformations more random. Turbulence is usually applied to soft bodies or particles to create the impression of wind or waves.
• Uniform  A field that pushes objects in a specified direction. Like the Gravity field, but without the progressive acceleration that Gravity includes.
• Vortex    A kind of rotating gravity, the Vortex field pulls objects in a spiraling motion that’s centered on the field’s icon. Often used to create galaxies, whirlpools, or tornados with particle systems.
• Volume Axis   A complex field that lets you specify a volume shape (cube, sphere, cylinder, cone, or torus) and then create effects that work within the shape. You can use the Volume axis field to create effects such as particles flowing around obstacles ,solar flares, mushroom clouds, explosions, tornadoes, and rocket exhaust.

OTHER  REFERENCES

Coins with nCloth

YOUTUBE

Falling Stuff – Rigid Body Tests

Contours of Vorticity of Vertical Axis Wind Turbine in ANSYS FLUENT – Vorticity

OTHER