For the rendering project a simple real world object had to be chosen which then had to be modeled and rendered in a scene using RenderMan; I selected an avocado for this purpose. The object had to be analyzed to determine characteristics of its surface and to realize them using RenderMan Shading Language (RSL).
The avocado is modeled as stretched sphere in RIB and a displacement shader is used to obtain the typical pear-like shape with many bumps of varying size. The usually middle to dark green surface that might have brown areas or be completely brown with some color variations is realized with a surface shader.
Displacement steps that are performed for the avocado shape:
Spherical shape – pear-like shape – add horizontal creases – add general surface deformation – add bumps – add grain.
Procedural creation of the texture:
Green surface – add brown areas – add green highlights on bumps – add damages – add yellow small spots – with environment map.