13 tips to speed up rendering by optimizing lighting
Lighting is probably the most complex and difficult part of 3D computer graphics. It's also the most exciting for me! It therefore requires many tests to differentiate the different volumes and obtain a realistic effect.
It is therefore essential to limit as much as possible the time required for each test.
We will now see 13 tips to speed up rendering by optimizing lighting.
- Limit the number of light sources;
- Reduce the range of light sources;
- Disable shadow ability for objects that do not need it - flat terrain, flat coplanar elements, hidden shadow elements, etc .;
- Reserve the use of raytracing to produce clean shadows;
- Configure Raytrace shadows with a Max Quad Tree of 8, 9 or 10;
- Limit the Falloff of your Spots;
- Limit the size of shadow maps, especially on PCs with low RAM. Optionally, increase the Shadow Range to use a lower shadow map resolution without risking crenellated shadows;
- Avoid using a GI rendering engine if you do not need hyperrealistic rendering. Software such as Maxwell, Mental Ray, VRay, finalRender or even the Radiosity and Light Tracer of 3D Studio max are much slower than the rendering scanline. They most often require specific materials and relatively long learning;
- Disable IM for objects that are too small or too dark to have significant influence;
- Use radiosity instead of the Light Tracer when only the camera is animated. Radiosity rendering integrates lighting information into each wall. It is therefore possible to calculate a walk without recalculating the lighting at each frame;
- Use Spotlights instead of Omni Lights. To calculate an Omni is to calculate 6 Spots!
- Simulate radiosity by using secondary light sources that simulate the indirect lighting reflected from the walls of the stage.
- Once the project is finalized, you can optionally use the "Render to texture" function to integrate the lighting directly into the textures. But no question of changing the lighting afterwards!
And that's not all! This list is far from being exhaustive!