Destructible mesh cast shadow issue

When “Cast Shadow” is enabled for my destructible mesh, the material bugs out. Firstly, it loses saturation and goes grey/black. Then these weird shadows streak across. I have nothing happening to my material whatsoever.

Video link : Google Drive: Sign-in

EDIT: Cast Shadow doesn’t appear to be responsible. Interestingly… when the chunks are falling through a dark black tunnel, the material seems to go black. Then when the chunks pop out the tunnel, the material seems to match the reflection of the sky.

Can someone please shed light on this strange behavior? It’s driving me nuts. It looks like it may be related to reflection? The floor material is actually white, and is reflecting the red’ish material above. So suddenly it loses all saturation and becomes grey/black…

Upon further research. I am finding out that this has to do with movable objects behaving in a statically lit environment. It’s not a destructible mesh problem, it’s a movable object problem. Tried lowering the Volume Light Sample Placement but to no avail.

It’s odd that before the collapse, the lighting is OK and I can control it. But it seems that after the collapse the shadow on the top side turns black.

That’s a unique problem. It’s seems like a light being generated under the mesh is taking lighting priority over your direct lighting.

Have you tried merging your Destructive Mesh into a new project and testing it on the default level? Did you get the same results?

I seem to remember answering this one, based on the video, from a while back, but I couldn’t find the specific post. :confused:

What’s happening here is that when the chunks fracture the chunks that are falling down into the darkened pit are using the indirect lighting samples from precomputed lighting which cause them to darker. This can happen when you have destructibles that are solely in indirectly-lit areas that have their chunks separated and spread between multiple volume sample points for lighting reference.


Thanks Tim. I remember we went through this too :slight_smile: Seems like ages ago. Took a lot of tweaking to sort of manually bake information that would lead to similar indirect lighting samples down the “pit”.

That was a hell of a lesson! cheers