- If there is no Surface Impact but there is a Surface Type then the fallback Surface Impact will be used with the detected surface.
- If there is no Surface Type but there is a Surface Impact then the detected Surface Impact will be used with the fallback Surface Type.
- If there is no Surface Impact or Surface Type then the fallback Surface Impact will be used with the fallback Surface Type.
- For performance reasons the surface system relies heavily on caching. Because of this you cannot:
- Manipulate the Surface Manager at runtime.
- Change surface settings at runtime.
- Manipulate hierarchies of any target object at runtime.
- Due to Unity engine internals, childing a decal to an object with a non-uniform scale (the x, y, and z scales are not identical) will result in decals that are strangely stretched/warped on such objects.
- UV regions on atlas textures do not work with Unity’s default primitives (cube, sphere, capsule, etc). It will only work on objects with a Mesh Filter and Mesh Renderer.
- UV regions on atlas textures do not work on static objects.
- Surface detection will not work if the collider is not static and the renderer is static.
- Surface detection will not work with multiple materials in the following scenarios:
- If the Renderer is static. This is because Unity merges the meshes of all of the static objects into a single mesh. Unfortunately, you must either make the renderer non-static or split the object into separate, single material static objects and assign the Surface Identifier to each.
- If the GameObject has a Mesh Collider. This is because Unity creates separate meshes for each material under-the-hood when rendering. The Renderer and Collider must share the same logical mesh for Surface Effects to work with Mesh Colliders.
A level geometry exists whose material / shader does not have a texture. How should it be associated with a surface?
Add the Surface Identifier component to the object.
My fallback Surface Impact or Surface Type doesn’t work.
Ensure there is not a Surface Identifier on the object. This will override all fallback settings.
A Surface Identifier is on the object but it doesn’t work.
- Verify that you have assigned a Surface Type.
- If you want to received decals, verify that Allow Decals is enabled on the Surface Identifier.
- Verify that there is only one Surface Identifier on the object.
- Verify that the object has a uniform scale.
Surface Effects don’t work on static, multi-material / atlas map objects
This is a very unfortunate limitation due to Unity architecture. When you mark an object as rendering static then Unity will merge the meshes together in a way that prevents the surface system from deriving material info / texture coordinates for effect spawning. At the time of writing there are three known solutions to the problem:
- Make the object non-static. This may be an acceptable solution if it’s not for all level geometry but just a few objects.
- Place invisible, static colliders above floors or walls with a certain texture and assign a Surface Manager to the invisible object.
- Don’t use multi-material objects, instead break the objects into separate, static objects.