Graphics Reference
In-Depth Information
How it works...
We mapped a colored image of a rock with the Box option available in the Image Texture
node (developed by the Project Mango team for open movie production of
Tears of Steel
to
quickly map objects without the need to unwrap them), and set the Blend factor to
0.200
to have smooth transitions at the corners. Although we had a tileable image texture, this has
been necessary because we set the Scale values for the three axes in the Mapping node to
0.250
.
First, by connecting the MixRGB node's Color output directly to the Color input of the Diffuse
BSDF shader node, we had a quick visual feedback of the image mapping, and thanks to the
ColorRamp node, we achieved the following goals:
F
We converted the colored image to a gray-scale image to be used for the bump.
F
By moving the color markers, we remapped the values of the ColorRamp node's
position values to reverse and increase the contrast (we could have obtained the same
result by processing the color map in GIMP, for example, by desaturating it and playing
with the curve tool). In any case, it's possible to visualize the ColorRamp node itself on
the object by temporarily connecting it to the Color input socket of the Diffuse BSDF
shader or an Emission shader node connected to the Material Output node.
This contrasted result has been applied as a bump map to both the Diffuse BSDF and
Glossy BSDF shaders.
Then we mixed a brownish color (the RGB node) with the Color output of the image of the
rock, and the result was added to the Image Texture node's output.
There's more...
We can improve the rocky effect by adding displacement to the geometry. Unlike bump or
normal effects on the mesh surface, which are just optical illusions giving an impression of
perturbing the mesh surface, displacement is an actual deformation of the mesh based on
the gray-scale values of a texture.
At least in this case, there is no need for precise correspondence between the already textured
surface and the displacement because it would be barely noticeable. Therefore, we can use
object modifiers to obtain a fast but effective result, by performing the following steps:
1.
Starting from the
Rock_imagemap.blend
file we just created, select the Cube and go
to the Object modifiers window under the Properties panel. In the Subdivision Surface
modifier already assigned, lower the Subdivisions levels for both View and Render to
3
.
2.
Add a new Subdivision Surface modifier and set the levels to
4
.
