Shady biz
Published: Mar 02 2024 by Last documented update: Mar 02 2024 by
This page explains how meshes are casting shadows.
Find information about shadows in the environment under Environment: Shadows
To learn more about Level of Detail (LoD), check the corresponding wiki page.
There are two different ways to cast shadows: real-time (generated) shadows, and proxy shadows.
Most in-game items use both.
Your mesh casts an actual shadow.
The real-time shadow will be extremely detailed, but it can impact performance, and it can glitch out or cause spectacular raytracing bugs. #proxy-shadows-shadow-meshes avoid these issues.
You activate real-time shadows by checking the following properties in your mesh component (which you can find in your .app or .ent file):
The proxy shadow, by contrast, will use an invisible mesh to cast a shadow (the shadow mesh). It has a lower Level of Detail than the original and often features a simplified geometry or even a proxy mesh.
Due to the less complex geometry, a shadow mesh is much less prone to raytracing glitches, and it will be much eaiser on performance.
Shadow meshes are usually added as entMeshComponents.
Your average shadow mesh has only one default material with a blank local instance of engine\materials\metal_base.remt. If the shadow mesh is loaded in a scene, it will lead to white, marshmallow-y overlays.
To make sure that it's only used for shadow generation, check the renderMask:
To create a low-poly mesh, you can build a cage, subdivide it a few times and use a Shrinkwrap modifier to shape it like your mesh. Then, you can reduce the poly count by decimating.
Check #configuring-a-shadow-mesh and make sure that RenderInScene is unchecked.
