RenderMan: Dynamic Secondary Geometry (Tree)


This project was done using Pixar's custom mel procedures to create secondary geometry at "render-time".  For this specific instance, we used it to create the leaves on a tree.

 

I decided I wanted my tree to have some catoonish aspects, but be in a more realistic environment, specifically something weird as if they had been grown in a lab and were now being documented.  

 

This project focused around adding objects to the scene by adding an extra step between your scene and the render.  This feature, as demonstrated with my code (which you can find below), is run on these spheres at rendertime, so none of the leaves are actually visible in the project.  This is a very significant feature with Maya because it can only handle so much geometry.  Putting leaves on a forest of trees in Maya would make the scen very slow, so this allows you to just add them at rendertime instead, so you can just use ! Below is a picture of what my tree looks like in the viewport.





The UI I implemented for this project was very straight forward. Each slider does precisely what the name descirbes. This was a great setup for my trees because the simplicity of the UI let me effect the spheres, and where I wanted everything to be, then with minmal slider tweaking, I could get the desired result.


 

This project let me explore Renderman in more depth which I really enjoyed.  Professor Kesson showed me how to use procedurally generated pattens, such as fractals, to alter the secondry geometries visibility in specific places.  This allowed me to use spheres as leaves, so I could keep the more cartoon-like effect I was going for, but add more interesting variation and interest.

 


Leaf Shading Network



Inspiration


This project was a bit more challenging for me, but I like where I got my tree to and feel that I learned a lot about both the front and back end shading techniques in Renderman. If I had more time I would have liked to explore the possibly of adding flowers, or something of that nature, to add more varience to the leaf area.