SurfaceLights casting shadows with artifacts

Bug Reports Engine Bugs
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#1

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I have a SurfaceLight casting light downwards onto the floor below the camera, however the light also ends up catching that desk on the upper floor, making the light have to cast a shadow of said desk, but its not casing the shadows correctly, making these shadow artifacts show up with this weird spiky pattern.

As of my knowledge, this appears to be caused by roblox’s lighting grid that SurfaceLights use to cast light and shadows while maintaining performance and resource usage to a minimum.

The other lights in the background do not influence this issue in any way, after taking the initial screenshot i tested it without any other light sources present.

I tested with every graphics API and (mostly) all gave the same result, with the exception of OpenGL which appears to not render Future-Is-Bright, completely ignoring it.

System Information:

  • Windows 11 (Heavily Modified)
  • Manufacturer: HP
  • Intel(R) Core™ i5-10400 CPU @ 2.90GHz (12 CPUs), ~2.9GHz
  • 16,384 MB RAM
  • NVIDIA GeForce GTX 1650 (Integrated) (Full Display Device)
  • DirectX 12 (DirectDraw Acceleration, Direct3D Acceleration, AGP Texture Acceleration)

Some more artifacts present:

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A private message is associated with this bug report

3 Likes
#3

Having the same issue, surface lights are unusable
I use spotlight with pointlight as a workaround

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#4

Yeah, I’ve also noticed that these artifacts don’t show up if the object is close to the source part or too far almost to the point that the surface light can barely illuminate it.

#5

This looks like shadow acne :frowning: I believe it’s a fundamental limitation. You can try and minimise it by reducing the size of the SurfaceLight and it’s Angle. The problem is exacerbated when the Light is larger overall because the Shadow map is only so large, so eventually the shadow pixels themselves get larger, which are the “spikes” you see.

#6

This is just an acknowledgment announcement!

We’ve filed a ticket into our internal database for this issue, and we will update you when we have further information!

Thanks for the report!