Monday, 25 February 2013

Unit 9: Adaptation - Maya Dynamics Series 1

Hello Everyone,

I am finally here with my first of many Maya posts, I sat down yesterday and went through all of the Maya Dynamic 1 videos which were I must say pretty fun. I made a video from each one (which confused Sammy) but I wanted to document them animated so I can refer to them if I should need a flame effect or rain here or there. I am afraid that I will forget them so its usually best to use them and catalogue them so I know the results that are achievable in Maya. I am probably most impressed with the Rain video, I had no idea such results could be achieved.

Anyway this series of videos are based on Maya 2013's Dynamics tray which uses particles to create various elements and effects. These are good for all kinds of things but more notably towards elements such as Fire, Water, Sparks, Etc. They have to be rendered separate to the standard Beauty and cannot be viewed in rendering engines such as Maya Software. The idea is to use Maya Hardware and render the effects separate and then drape them over the top for the sections required in an animation. Those of you who know of the art of Render passes let me just tell you it is key here too, hell it probably is in all instances of 3D animation.

Anyway lets get down to the videos, I will break them down so I have an idea should I need to revisit them in the near future :) Enjoy!

The first video was clouds, I was a little disappointed with the size of the blobs, from my experience clouds are less bumpy... more vast. Anyway if you hadn't guessed it the clouds are built from particles with elements of gravity weighed in. As the ship passes through a Make Collide on the ship pushes the particles to the side as the ship makes its way through. The trick here was giving the particles the right degree of resistance. In hindsight I probably should have forced them out more gradually as the ship passed through, hey ho.

Next the explosion, quite fun to make this one. The particles were given gravity so they would fall down of course I had to be a little cautious with the strength of the Gravity. The emission rate was delayed long enough to gather particles and was then released briefly on a key point of the timeline which caused a burst of sparks to fire. The colour was an expression with in ColourPP and then OpacityPP was provided a ramp to gradually diminish the rigidity making it seem more erratic. I really enjoyed this little animation ha-ha.

Next comes the fuse that lights the bomb. This was a total of 2 passes as I wrote above you had the FX pass which uses Maya Hardware and you had the Maya Software Pass which is the Beauty layer giving use the image of the nice shiny bomb. The two are then put together in After Effects and screened onto each other. The fuse was a retracting extrude which was keyed to get shorter. The fuse utilized the opacityPP and colourPP stated in the explosion video. The particle emitter was placed on the head of fuse facing away which followed the animated extrude.

Next came the Smoke Particles. The trick here was using the opposite effect on the Gravity field causing the smoke to rise as opposed to drift (like the clouds). The turbulence field was used to differentiate the smoke as it rose causing it to look more randomised. The emitter was placed in the doorway and the rate was keyed to release when the door became more ajar. The colour values were messed around with mainly to keep the dark mass in the centre of the smoke causing it to become whiter as it rose and dissipated. Again made of two passes.

The name of this video was originally Firework 2 but I kind of thought it to be like a "Catherine Wheel" which rotates around and around. This video was relatively simple as it used a nurbs circle as a motion path the particles were simply emitted from the circle and were gradually spun around and around. The same expression was used in the ColourPP channel as in the previous firework chapter. The opacityPP was again used to gradually dissipate the fireworks flame as it moves around is isolation. Cool thing to make but this probably wont be used as much as the others.

Next came the Shockwave which is something I have simulated before in After Effects but in a much more cartoon sense. In Maya the trick was once again based on a nurbs circle which grows and expands out of the screen. The trick is what happens in the middle as a gradual random decay with draws with the outer rim of the circle. The particles move with the edge of the circle the opacityPP once again pulls the inside out with turbulence differentiating the edge of the circle to create a less hard of an edge. ColourPP as per usual with an expression.

The Water Foam video was lacking some textures much to my confusion but I put it to one side. I also have the feeling that this is meant to be an image as opposed to a video (it took a long time to render Beauty to be fair). Anyway the particles on the edge of the island are created where the sea and the island meet. I think this was done using a Make Collide (cant remember this one well, sorry). Anyway a curve is created for the edge and it animates with the sea as it moves in and out of the island. There were a few issues with the passes synching up however.

The Flow Curve scene was mostly setup already it was our goal to put the moving flames across the motion path which intertwined the "A". The rate slider was used once again here in a burst so that the effect passed through and then stopped. The particles were emitted from the object, the trick was getting the particles to move along the path. The same trick was used in the fuse for the bomb only this time on an invisible path. The flames were created using an expression in the ColourPP and the flames were decayed by the OpacityPP.

Next came the Rockets a much more satisfying firework if I do say so myself. For this we were to create additional emitters on the ends of other particles. These were triggered to go off at a specific point in the timeline. The colour was the work of a ramp. The fireworks flames were used the same as the videos above. The Gravity field was used to push the fireworks up and out creating a subtle curve as they rise and explode. After rendering I noticed a little bit of a flickering in the end animation not sure what I did to get a stutter but it could have been anything...

The Barrel Flames, a very interesting one this was because it took so much admin to get right. The particle animation was based on the placement of a distorted ramp which was animated to move and change eventually encasing the entire barrel. The particles were then told to follow the movement of the ramps black colour value and expand as the colour did. Gravity was then added to pull the flames up as they got gradually bigger. Turbulence was placed over the top to create some variance between the particles as they expanded from the base of the Barrel.

The disintegrating coke can ahhh good days... This video used values very similar to the Barrel various ramps were used to make the can disappear as an effect disintegrated another variation of the can. This was obviously used in an effect and beauty pass. Gravity and Turbulence were used to make the particles flow upwards and obviously make them more random. Randomisation was also used on the particles themselves so they gradually split and dissipate. This was quite a cool effect to make, I will probably have to have a refresher on this one.

Next Active Rigid Bodies something I had no idea existed in Maya. It basically allows the user to assign active and passive entities in Maya (e.g. Active - Bowling Ball, Passive - Bowling Alley). It basically assigns properties to hard surfaces or objects allowing them to collide. Gravity is assigned to the ball and some velocity has been placed so it moves down the alley. This required no animation keys what so ever. This was just based on the values entered in the Active bowling balls attributes, the pins at the end have no gravity which is why they float.

Next came the collision of raindrop particles onto floor and an umbrella. First the particles were emitted from a plane at the top of the screen. The particles had to create other particles when colliding with the floor plane (this was done using Make Collide). The same attributes were applied to the umbrella with one big exception. The floor had a dummy plane which was used to gradually decay the particles further as they hit the floor. This creates a more realistic rain spatter effect then the rather unrealistic puff particle spatters which were there originally.

The metal object collision was very much like the rain drops the only thing that changed was the sparks and of course the objects properties. The dummy plane was once again setup and was used to make the effect more realistic. The sparks were tidied up a little in post (after effects) which had a slight glow modifier added. The render passes were used for this video but I had a weird issue with it rendering out my sparks black and white when I clicked batch render. Strangely it worked when I rendered it out frame by frame, I have no idea it was just annoying.

Last but not least came the Space Travel document, something which I was a little sceptical over. I was quite sure in the beginning that I was doing it wrong. Anyway the particles were projected across a long emitter so they could create the illusion of coming towards the camera. The shot cam was placed in the middle of the action. The moon was keyed to gradually grow and move across the screen (supposedly as the camera gets closer). Of course the camera isn't moving anywhere, the sphere just scales and moves. I thought it was quite cool in the end.

Well I think that concludes this little post on Maya Dynamics (at least for series 1). I enjoyed this a lot more then I thought I would and I defiantly have a little more knowledge of particles now. I just hope that soon I may be able to use them on a project. I may put a bit of smoke coming from exhausts for this project (Adaptation) not sure though it all depends on if it works when I get around to it. Either way I have other Dynamics videos to get on with and a games character process to actually learn for my up and coming models.

Take it easy people!

1 comment:

  1. Stitch - you missed today's briefing - see below...

    can you email me - I need your email to create a dropbox share - thanks!