Dynamically shaped plane is not casting shadows

noillimryM · June 14, 2021, 9:45am

Hi everybody,

I’m currently having an issue with shadows and I can’t quite wrap my head around it.

First of a all, I have a terrain which is generated from noise and applied to a plane through a Material with world displacement. This seems to be working all well as I obtain the expected results shape-wise : I have a “mountain” looking landscape.

I also use the NormalFromHeightmap material node, for my terrain to react correctly to light which, once again, seems to be working fine. However, the “moutains” in my terrain don’t seem to be able to cast shadows but other objects can (such as the cube in following pictures).

My plane ( StaticMeshActor) is Movable and my Light Source ( DirectionalLight) is Movable as well. I understand all these mountains are part of the same plane and are dynamically generated (as I can, for example, change the noise scale at runtime to obtain different shapes). But I don’t think this should matter, or ?

Would somebody have any idea how to get the mountains to be casting shadows ? Thanks a lot in advance.

noillimryM · June 14, 2021, 10:25am

Somehow, I tweaked the Contact Shadow Length parameter of my Light Source ( Directional Light) and for the first time I’ve got some sort of mountain shadows being casted :

It does dynmically change based on the lightning, however if I move around the scene and get closer to a shadow, it starts shrinking. Why would the shadows depend in any way on the distance to the camera ?

Once again, I just tweaked a parameter and it happened to create a reaction, but it most definitely isn’t the solution. I just thought it may give more informations to somebody to understand what’s happening.

noillimryM · June 14, 2021, 5:19pm

I have found the problem ! For some reason, the Cast Ray Tracing Shadows options of my Light Source (a DirectionalLight) had to be disabled. I, however, have no idea why I cannot use Ray Tracing for my shadows.

Since the problem mentioned in this post is “technically” solved, I have created a new one to specifically address the Cast Ray Tracing Shadows issue.

It is currently waiting approval by a moderator.