Friday, 9 October 2015
Here's another commercial I was involved in, in my personal time. I helped with simulating the berries in the container. This was done with Maya nParticles.
My partner Kuodo did everything else in 3D Studio Max.
In Maya, I instanced the model of the Acai berries to every particle. With nParticles, I was able to fill up the berries in the container while maintaining their volume. This means that the particles will not collapse down on each other, which will happen with Maya's classical particles.
At my request, Kuodo provided me with animated caches of his characters. I used these as collision objects in my simulation.
One of the challenges after getting the simulation correct was how to export Maya's particle instances as regular geometry back into Max so Kuodo can shade and light it.
If you have worked with Maya particles, you will realise at some point that particle instances in Maya are not regular geometry. They cannot be exported to geometry formats like Alembic, FBX or even OBJ or DFX. Particle instance objects are points in space that only show up in the viewpoert and in renders.
Eventually, I reached the decision to write a Python script to duplicate the single berry source geometry and place it at every nParticle point. Besides matching the position of each berry particle, I also needed to match the rotation and size of each particle (I varied the particle sizes to achieve an overall natural and organic look).
After creating the berry instances I then proceed to step through each frame in the frame range to key each of them to the new position of the respective particle they represent.
In the course of exporting data between Max and Maya, I discovered joy and convenience of Autodesk's collaboration and pipeline features. The "send to Max", "send to Maya" and "update scene" features worked seamlessly, sending geometry and hierarchy data to and from Max and Maya without a hitch! This saved me a lot of time generating intermediate export / import files. It also minimised errors concerning axes orientation, and scale differences between the 2 applications.
After all the simulation, there were still a berry or two that needed the movement to be refined. One of them would be the trajectory of the few berries that the main characters scooped up in their hands and threw up in the air.