Rendering molecules with Povray

Povray is a is a high-quality tool to create 3d graphics. Here is my notes on rendering molecules and coarse-grained models.

Ray tracing:

global_settings {
    radiosity {
        count 60
        always_sample on
        recursion_limit 2
        error_bound 0.8
    }
}

Texture:

texture {
    pigment {
        bozo color_map{[-2 rgbt <0.3, 0.3, 0.3, 0.0>][1.0 particleColor]} scale 0.25
    }
    normal { bumps 0.3 noise_generator 2 scale 0.08 }
    finish { specular 0.8 roughness 0.2}
}

Result:

As marked by blue square, the boto controls the dark spots on the sphere, and bumps creates the look of rolling hills. The specular keyword in a finish statement produces a highlight, which more closely resembles real specular reflection and provides a more credible spreading of the highlights occurring near the object horizons.