Texture and Light for Architectural Exteriors - 3D for Graphic Designers - page 401

A mixture of both techniques will give the best combination of polygon reduction and speed increase.
The essential goal is to re-create the Displacement As Bump option manually to save memory and increase
speed. A material like this can be created by changing a few settings as follows:
1. Set Minimum Spot to 30. The rock texture is high resolution, so with a lower-resolution image, the
setting can be lower.
2. Duplicate the displacement image layer and set the effect to Bump.
3. Reset the Minimum Spot setting on the bump layer to 1.0.
4. In the Render Properties tab, set the Displacement Rate to 6.0.
5. Disable Displacement As Bump (the effects are seen through the addition of the bump layer).
6. Increase the Bump Amplitude on the Material properties to 40 mm (matching the Displacement
Distance).
The finished result is shown in Figure 11-19 . The render represents about a 90% decrease in render time
over the original Displacement rendering and an 85% decrease over the simple Displacement As Bump
render.
Use the Specular image in both the Specular Amount and the Reflection Fresnel. In the case of this tex-
ture set, the values are low enough that the Low Value can be left at 0% and the High Value at 100%. When
creating materials with other textures, these values (especially the High Value) may need to be adjusted.
Leave Blurry Reflection disabled while fine-tuning the reflective values. After an appropriate amount of re-
flection is achieved, Blurry Reflection should be enabled. Because reflections on a porous material carry
the same colors as the material, create two instances of the Diffuse Color layer for use in the Specular and
Reflection Color channels.