Thank you sooo very much for sharing this valuable data. I feel I stroke gold here. Thank you. Was driving me nuts, this issue. Now I can go back to my original project. Life saver!
Hey thank you this is very helpful!
I tried the worklfow given by @eklein and I see now that you are talking about issues with shadows (shadow-maps).
Just want to show that there is also an issue with screenspace:
It shows a floor (with thickness) and a wall around it. You should see at the red arrow top-right the wall reflected on the floor, but because that part is at the edge of the screen (top, right) the screenspace doesn’t pick that up. In this particular example you don’t see it in the render, but it renders show such effect as well under certain circumstances (angles). Also you see the white edge on the right, also caused by the screenspace not picking up the wall in the reflection on the floor.
The workflow that I posted is about light leaks caused by incorrect shadow maps. If you turn off “Screen Space Reflection” and “Free Lighting Cache”. Do you still see the white line artifacts? Is better if you post the problem scene.
For dealing with the limitation and artifacts of screen space reflection since it can only use reflection of what is visible in 2d space. Is probably better to start another thread about solving these problems. To have screen space reflection work correctly for floors and walls you may need to add reflection probes. See my solution in this thread Eevee Reflection Clipping.
Hello, I came across something which could be considered as a bug, but I wanted to share in this thread.
I opened rather old archviz showcase scene from blender.org. I wanted to test irradiance volume probe on a simple scene as this one, but I have noticed lack of color bleed. Even after replacing the irradiance volume objects (which seem to have have some visibility bugs) with the new one of the same size and density (from the current daily build) problem persisted. After the indirect light bake, there was just different intensity of the red floor, which I put on purpose, in order to make red light bleed more prominent. So from perspective of irradiance voulme probes, problem of light bleed was not cause of new/old volume probe objects. I tried appending all geometry objects into a new scene, but problem persisted. Than I came to the conclusion that the problem is caused by some (hidden data?) stored in the mesh or object. Soon as I joined the floor object to the newly created plane object, the light bleed worked fine! The scale of the floor was at 1.1.1. Other mesh and object properties seemed normal, but still inheriting object data from new object fixed the problem! The question is, what is the hidden attribute I am missing? If this problem remains than any imported objects from other scenes (2.79 or 2.80) could carry some bug which could not be even apparent to us but would affect the proper color bleed.
This gif shows difference of default indirect light bake with the light bake with floor joined to the new plane object: (notice the correct bleed on the gray chair on the far left, in the second case)
Now, this is more emphasized version of the same case, just with the more prominent floor color (second case with the floor joined to the new object has the light bleed):
And if someone was wandering if the problem was in the probes itself, this is the same floor color with the newly created irradiance volume probe (color bleed, and color of the floor itself is interpreted differently, but other than that, problem of the original floor object lack of color bleed, seems to be same):
If I had to render this scene “correctly” in EEVEE in this fashion, I would probably have to write a script which would join all existing objects to some null objects. I hope that the cause of this strange behavior will be demystified for the sake of all possible sources of importing and appending models to the new version of Blender and making sure that they would work as expected in all cases.
I think, that with point lamp You don’t get any bounce light when baking. I tried to change color of world sky, but the sun from point lamp didn’t get on any wall…
Sooo… Are these light bleeds and weird artifacts considered a bug and will be fixed, or is it just a limitation of the engine that we’ll just have to live with?
Ever played a video game ? That’s the limitation of such engines