We are experiencing problems with Distance Field Shadows. We are getting black lines on our rocks. All of our rocks + this occurs on multiple computers so it we therefore believe it is unlikely to be a driver or hardware issue, or related to this specific model.
4.6.1
DF on the rest of the game work fines, but this type of bulgy rock produces these lines consistently.
This is DF shadow related, not AO. If I turn off the shadows via the console the lines go away.
Changing DF to double sided does not help, increasing the resolution does not help either. The latter just makes the lines thinner but they are still there unless I set to resolution excessively high (10 or so - but then the lines are still there, just too thin to notice).
Is this a known problem? Are there any fixes planned for this? This has a large impact on our graphics and is very noticeably wrong to the player.
Can you post of screenshot of your Visualized Mesh Distance Fields in this scene? Also can you let me know if the mesh itself is scaled in the editor at all?
The mesh is not scaled at all. It is dragged in from the content browser and that is it. All settings default.
It has a second lod step, but I tried without lod and it is the same. So doesn’t seem related.
It has 1929 tris, and the entire bottom part of the rock is an open edge (possibly related).
The visualization appears ok to me.
I have just tried importing this into a new empty project, and the problem occurs there too with all settings default, so it is not something I set wrong within our game I believe.
Ok I definitely see what you are seeing on my end, so I also checked out the asset in our Main internal branch and it actually looks great no lines. The results you are getting are indeed a limitation currently which we already have a solution in place, so it well be coming soon. I should note that it is not currently in 4.7.
Ok thanks. Do you know if this might still make it into 4.7 by the time it releases? We are showing the game at GDC, and the black lines are particularly obvious. Turning off DF shadowing is not an option (also very visible due to lack of shadows in the distance).
I should note that Daniel has been hard at work improving and expanding the Distance Field Shadows so that singular commit may not be the sole solution they may be several updates between 4.6.1 and the current Main Changelist that would need to be integrated.
We just switched to 4.7.2 now, and the problem appears to still be there. I haven’t tried in a test case level, but it still clearly appears in my real levels. I tried setting the dir light back to default settings but the effect remains. The scale of the distance field on the mesh is also the default 1.0.
My Nvidia drivers aren’t that up to date, but since this effect was here before on multiple PCs I assume it is still the original problem that is still there.
Apparently the full fix for this bug was expanded and is not scheduled for release until 4.8. I did test your rock and as you can see below, with the new Ray Start Offset Depth Scale you can effectively remove the artifacts.
