Modelling rubber chain tread #43903

[Roland Dahl]

Hi Steffen,
here are the rubber definitions I used for this render:

#declare lg_rubber_finish =
finish {
ambient 0
diffuse 0.5 // Default is 1
phong 0.5
phong_size 20
reflection 0
conserve_energy
}

#declare lg_rubber_normal =
normal {
bumps 0.1
scale 0.1
turbulence 0
}

// 256 RUBBER BLACK [LDRAW]
#declare lg_rubber_black = texture {
pigment { color srgb <33/255, 33/255, 33/255> }
finish { lg_rubber_finish }
normal { lg_rubber_normal }
}

But these are more or less default values as specified by the lgeo-library (see lg_color.inc). The only variation I did is to reduce diffuse from 1 to 0.5.

Regarding lighting I usually use an horizontal area light as a main light:

light_source { <-4000,-6000,-4000> color rgb 1 area_light <8000,0,0>, <0,0,8000>, 8, 8 adaptive 1 jitter circular orient

Sometimes I add vertical area lights too, mainly for getting a better general illumination of the model respectively for enlighting dark areas:

light_source { <-2000,0,0> color rgb 0.3 area_light <2000,0,0>, <0,-2000,>, 6, 6 adaptive 1 jitter circular orient } (or similar)

Sometimes I add a simple light source at camera position, mainly for getting rid of strange render artefacts :
light_source { LDXCameraLoc color rgb .5 }

You can see these artefacts when you have a close look to the yellow wheels.The surface is not uniformly rendered: There are some dark and bright areas side by side.

But for the quick render above I only used an horizontal area light.

Last year I prepared a short tutorial about lighting. You will find some more information about my render settings inside.

Please feel free to ask again. Glad when I can help.

Regards
Roland