How Displacement Maps Work
When using displacement maps the displacement procedure creates additional geometry in the scene at render time. This means that this new geometry will be added to the calculation of light, materials and visibility. Displacing geometry in a scene can increase the render time significantly especially if its in high quantity.
Tips for Using Displacement Maps
Because displacement maps require extra memory and processing time, care should be taken with using them. Typically:
- Use Displacement Maps only when needed.
- If a Bump or Pattern map give you the same result, then there is no need for a Displacement Map. Remember, normal Pattern and Bump maps are material properties, whereas a Displacement Map actually is new additional geometry.
- Apply displacement on visible items only. If the beautiful wool rug you’re using in the interior shot is being displaced, but only a small strip of it is visible, then slice the rug and only apply the displacement to that small strip. Luxology rendering will have to calculate the displacement off screen if there are any refractive or reflective materials that may catch the displacement. If there aren’t any refractive or reflective surfaces, Luxology does not to have to calculate the off screen displacement.
- Adjust the displacement settings in the Render settings properties tab to suit the need of the rendered shot. The default Displacement Rate of 1.0 may be more than what is needed for the render. Try increasing this setting to 1.5 or 2 and do a preview or region test render.
- Slice up displaced geometry to smaller physical segments. This helps Luxology in utilizing memory management at render time and will decrease render times. There is no need to over do it as you will increase your render times if the polygon count goes too high. A little hit and miss experimentation in the scene will help you in the long run.