Graphics Programs Reference
In-Depth Information
This contrasted result has been applied as a bump map both on the
Diffuse
as well
as on the
Glossy
shaders.
Then, we have mixed a brownish color (the
RGB
node) with the color output of the
rock image. The contrasted values of the
ColorRamp
node have been used as a
factor for the mixing of the colors, thereby giving more and nicer variations to the
surface.
In the last optional step, we added more variations to the coloration by also calculat-
ing the "difference" between the image and the
RGB
color, with the contrasted gray-
scale output of the
ColorRamp
node as blending factor, and we added it to the final
result using the
Color
node.
There's more...
We can also improve the "rocky" effect by adding displacement to the geometry. Un-
like bump or normal effects on the mesh surface, which are just optical illusions giv-
ing the impression of a perturbed mesh surface, displacement is an actual deforma-
tion of the mesh based on the gray-scale values of a texture.
At least in this case, there is no need for a precise correspondence between the
already textured surface and the displacement, because it would be barely notice-
able, so we can use object modifiers to obtain a fast but effective result:
1. Starting from the
Rock_01
file we just created, select the cube and go to
the
Object Modifier
panel. In the
Subdivision Surface
modifier already
assigned, set the
Subdivisions
levels for both
View
and
Render
to
3
.
2. Add a new
Subdivision Surface
modifier and set its levels to
4
.
3. Now add a
Displace
modifier and click on the
Show textures in texture
tab
button, the last button to the right of the
Texture
slot. This switches
the
Textures
window on from where we can click on
New
and then
change the default
Clouds
texture with a
Voronoi
texture. Set the
Size
value to
2.00
and let the rest be unchanged. Go back to the
Object
Modifier
window and set the modifier strength to
0.300
.
4. Add a new
Displace
modifier. Switch to the
Textures
window and assign
a new texture. We will use the default
Clouds
texture now, but just
change the
Size
value to
0.50
and
Depth
value to
8
. Now, back at the
modifiers, set the
Strength
value to
0.350
.
