Why are shadows bleeding on my mesh?

[anonymous_user_7dbf6780]

Why are shadows bleeding here? It’s just a 3 aligned planes, also I have the same issue with more complex modular meshes. So what’s wrong?

[Tim_Hobson]

There are a couple of things you’ll want to check and do.

1. When you make your second UV for your lightmaps make sure that the verts are snapping to a the grid. You’ll need a target LM resolution to set up the grid properly.

For example, 1 / [target LM resolution] = grid spacing

If you target 64 LM resolution you would do: 1 / 64 = 0.015625 grid spacing for your Second UV

2. If you’re using Planes here you’ll want to make sure that you have another mesh behind it to occlude the light or either make your planes into Boxes. If you look in the Realistic Rendering Demo you’ll see that our walls are Planes but we have other meshes there outside the planes to block additional lighting.

3. Finally, if you’re using modular walls like you mentioned you will want to make sure there is no gaps between the walls, The walls have a decent thickness to them, and you have a lightmass importance volume in your scene.

Increasing the LM resolution and building lighting on higher settings than Preview. I’ve seen users solve their issues sometimes by building on anything higher than Preview.

Give these things a shot and let me know how it goes.

Tim

[anonymous_user_7dbf6780]

I did everything, what you mentioned, vertices snapped to grid according with LM resolution, scene have a lightmass importance volume, and doesn’t have directional lighting(because it’s not needed for this scene), I tried to build light with production quality, but it doesn’t help at all.

[Tim_Hobson]

Here is an example of my scene. I’ve not done any of the setup above really but here are my results using a single plane. (I did increase it to 5 times it’s size in the editor to use though.)

[Dropbox - Error][1]

Here are my results:

My set up:

I used a new level default
Imported the FBX Plane
Scaled it to 5 on the XYZ axis
Added a material to the wall that is two sided (since this is a plane and the back face is culled)
Placed them so that the corners line up and baked lighting on Preview.

I’m not sure how your scene is setup but can you give this a test as well with my asset and see if you get the same results. This may help in narrowing down what is exactly causing the bleed on your end.

Tim

[anonymous_user_7dbf6780]

That’s what I’ve got with your plane.

[anonymous_user_7dbf6780]

So, my problem will be ignored?

[Tim_Hobson]

Hi Dtx12,

You’re issue is not being ignored. I have multiple issues assigned to me that I must look into and I currently get to them as quickly as I can. Some may take longer to look into than others as well. Usually Monday’s and Tuesdays are the busiest with issues since there are questions and bugs we must look into that were submitted over the weekend. We currently do not have support staff available over the weekend, which is why I’ve not been able to look at it in the past couple of days. I will get back to you as soon as I can with this one. I thank you for your patience.

Tim

[Tim_Hobson]

Thank you for your patience here.

Looking at your image and the difference between our two is that it looks like you’ve still got a directional light that is providing the light that is creeping in around the edges.

Planes will not fully stop light by themselves fully. You will need to have other meshes around them that will help prevent this from allowing the leaking light (as I’ve got pictured below) or you will need to have meshes with some amount of thickness that help with this. If you look at the Realistic Rendering demo from Epic in the Marketplace you will see that this is how we handled using planes as well. There are other planes around the outside of the apartment that block the lighting to keep leaking down.

With wall meshes with some thickness there may still be some leaking but usually this can be fixed by building lighting on levels higher than Preview and by having a little overlap.

All of these were created in a default scene with a directional light on.

Image 1: This is the planes aligned with a point light in the center of the room. with a directional light

Image 2: This is the same as above with the point light removed.

This is to be expected.

Image 3: This is using an enclosure around the planes to block excess light.

Image 4: This is the a shot from inside as it’s pictured above with one wall left open. You can see the left side which is fully enclosed has no light leak. The right side has leak.

Image 5: This is with the room fully enclosed. No light leak.

If you’re not using a directional light you can turn this off and get no light leak. You have a few options with this to plan your scene accordingly depending on what you want your end result to be.

Tim

[anonymous_user_7dbf6780]

This is my scene with your plane, where planes enclosed with cube, lighting builded in production quality, and as you can see I still have problems with shadows bleeding.

[anonymous_user_7dbf6780]

So still no answer after 6 days?

[anonymous_user_7dbf6780]

Well, I guess I have no choice, except closing this question, thank you for your help Tim, anyway.

[anonymous_user_f77a82de]

This answer is highly complicated and a lot of math involved I went through the same thing you have quite awhile, I can’t think of a logical way to explain it’s a very complicated task.

[anonymous_user_f26c856c1 (anonymous_user_f26c856c)]

Hi!

I haven’t read the ones above but this is due the low Indirect Light Quality!!
Go somewhere between 4 and 10!!
Also your scale is set to too low: you don’t have a lot of detail in the scene so you won’t need to go that low!
I’d set the smoothing a bit upper /1 even!/! Again: you don’t have small details that would be washed away!
Your lightmap resolution seems fine!

Good luck!!