PR Rendering with Renderman

Problem Statement

To render a transformer in Renderman with the following effects:

• Indirect Illumination (Color Bleeding)
• Scene elements with caustics
• Area lights and soft shadows
• Texture mapping
• Transparent and metallic objects

A more detailed problem statement can be found here.

---

Code Structure

The code has been modularised into separate RIB files and using the ReadArchive command we patch the files together. Shaders are organised in SL files. A caustic map is separately generated as caus.cpm from caus.rib A makefile compiles everything and generates an image.

---

Dependencies

• Renderman Pro Server 19
• python 2.*

---

How to Run

To run the code, simply use the makefile with the command:

make

You can see the resultant .tif file generated by running:

sho display-transformer.tif

To clean up the generated files and the image generated, do a

make clean

---

Shader Details

We use the following shaders in this assignment:

• shadowlight: This is a light source shader which causes local illumination at a point only when the poing is unoccluded by any other object
• diffsurf: This is a surface shader with local illumination, indirect lighting and caustics (From a cuastic map)
• texsurf: This is a surface shader much like diffsurf, except, the illumination is used as a weight for a color obtained from a texture map
• metal: This is a surface shader which has a high specular component and high reflectivity. The shader calls the trace function to raytrace the reflection
• transparent: This is a surface shader with very low local illumination and reflection. Most of the light is refracted and raytraced.

---

Effects Details

The following required effects were achieved in the assignment:

• Color Bleeding: Using indirect illumination in the diffsurf and texsurf shaders.
• Area Lights and Soft Shadows: Placing multiple point lights closely.
• Texture Mapping: Using the texture function in texsurf shader.
• Caustics: Photon mapping the scene to generate a caustic map and then adding it to the illumination.
• Transparent and Metallic Surfaces: Using the transparent and metal shaders respectively.

---

Result

The following image was generated:

The generated tif can be downloaded from here.

---

Credits

• Pixar
• Renderman Docs and Forum
• Rohan Prinja

---