Lighting Problem: Unknown highlights

cbates540

Hey all, I'm making a recreation of an office space and encountering a problem with lighting on the doors. I don't know how or where I'm getting a highlight and shadows from. The lightmap seems okay, and I've tried my best to block off the directional light except where it's needed. 

I'm still learning how to set up good lighting, so any general advice is also appreciated. I've been studying the "Realistic Rendering" file along with the interior lighting tutorial and they've helped quite a bit!

leleuxart

How thick are your walls and do any of them stick outside? Your Lightmap resolution might be too low for the mesh as well, which just exacerbates the problem of light leaking. If your walls are too thin, light can bleed through them, or if your walls go outside above the ceiling, any light on that top part could bleed through the ceiling and into the room.

And just to be sure, you have a Lightmass Importance Volume and Lightmass Portals right?

cbates540

I tried bumping the lightmap resolution up to 128 and no change. My walls are decently thick, so I don't think it's light coming through. I feel my set up is a bit of a hot mess, but the result is actually a big step up from how my interior lighting used to end up. I was having problems with light leaking through where the walls and ceiling come together, so I put everything inside a large bsp with an inner hole in it, and then made a couple slots where the windows are that I wanted the directional light to come in. I also added extra bsps around the crease between the walls/ceiling/floor where the light could get in in an attempt to stop any light leakage there. (See images for what I'm talking about.) 

I had an importance volume but I had never heard of the portals! I added them to just behind all the blinds in the windows. Things seem too bright now but that will just mean more tweaking. They did not fix the issues with the doors or the blotchy shadows on the walls.  

Alanandrade92

Hi Cari, it seems that you have a lightmap resolution problem issue. Try to increase the lightmap resolution of your problematic meshes (WARNING: this could cost on your performance). Also, try to see the lightmap density of your scene. Basically, what this mode does is show your UV lightmap texel density resolution. when your mesh is blue, it means that you have a low texel density res, if it's green, it means that your res is fine and red it means that this res is overwhelmed (I dunno if it is the right word, sorry, lol)

You can access this mode by going to your view modes (top left screen of the viewport, 3rd button), go to optimization viewmodes and lightmap density, or simply ALT+0. 

You can find some pretty good stuff too about that theme on Unreal Documentation: https://docs.unrealengine.com/en-us/Engine/Content/Types/StaticMeshes/LightmapUnwrapping

cbates540

Alanandrade92 said:

Hi Cari, it seems that you have a lightmap resolution problem issue. Try to increase the lightmap resolution of your problematic meshes (WARNING: this could cost on your performance). Also, try to see the lightmap density of your scene. Basically, what this mode does is show your UV lightmap texel density resolution. when your mesh is blue, it means that you have a low texel density res, if it's green, it means that your res is fine and red it means that this res is overwhelmed (I dunno if it is the right word, sorry, lol)

You can find some pretty good stuff too about that theme on Unreal Documentation: https://docs.unrealengine.com/en-us/Engine/Content/Types/StaticMeshes/LightmapUnwrapping

Hi Alan, I have bumped the lightmap on the door up to 128, but there was no change. I have been using the lightmap density view to check my lightmaps, and at 128 the door's lightmap is starting to register as being too large, so I'm not sure increasing its size would help.

What is interesting to note is that the door, the door frame, and the wall are all separate models, so whatever is causing the incorrect highlight on the door is ALSO creating it on the door frame, but not the wall. I will try recreating their lightmaps and see what happens later. 

The good news is, after a professional quality lighting build, most of the blotchy shadows on the walls were taken care of!

Alanandrade92

Hey,

Nothing that a build in Production can handle, eh? hehe

About the door, taking a look at your lightmaps I assume that separating the edges on the left UV island can somehow resolve your issue, since there is lighting bleed, if you split the edges and pad correctly these islands should get a individual lighting/shadow information, reducing the amount of errors...

Somehow I just can't upload a picture here  .. but I'm sending you a link to what I'm trying to say.

https://drive.google.com/file/d/1LqjU742g-fgTid5hq7ck0sP7Wj3fQ-OP/view?usp=sharing

cbates540

Alanandrade92 said:

About the door, taking a look at your lightmaps I assume that separating the edges on the left UV island can somehow resolve your issue, since there is lighting bleed, if you split the edges and pad correctly these islands should get a individual lighting/shadow information, reducing the amount of errors...

That's what I was thinking as well. If the highlight still shows up after that, I'll definitely be back and more confused than ever lol. 

Alanandrade92 said:

Somehow I just can't upload a picture here   

I've had such a hard time uploading pictures as well. I've ended up just linking them in the html and ignoring the upload image button completely.

Thanks for your help!

Alanandrade92

Lupe540 said:

I've had such a hard time uploading pictures as well. I've ended up just linking them in the html and ignoring the upload image button completely.

Thanks for your help!

I thought I was the only one with the image upload issue.

Come back and post the results if everything went fine (or no). hehe

cbates540

So I redid the lightmaps for both the door and the door frame, built on professional level lighting. No change at all. I adjusted the largest reflection sphere to include the back wall (all other walls are included), no change. I have turned off the 2 nearby ceiling lights and built on medium quality. This is the result.

These are my lightmaps.



Whatever is causing the highlight is definitely coming from outside the room or caused by something funky about the wall. The door and door frame are grouped together in a blueprint. Could that also have something to do with it? The bp doesn't do anything at the moment, but I set it up so I can give the door interactivity later.

Alanandrade92

Lupe540 said:

Whatever is causing the highlight is definitely coming from outside the room or caused by something funky about the wall. The door and door frame are grouped together in a blueprint. Could that also have something to do with it? The bp doesn't do anything at the moment, but I set it up so I can give the door interactivity later.

Well, this might be the problem in the end, because when you use a static mesh on a blueprint I think it sets the lighting to Movable, therefore that static mesh on the blueprint will receive only dynamic lighting and shadows. However, this can be overriden if you go to the mesh details inside the blueprint and set to receive Static Lighting, from what I remember is here.

cbates540

Alanandrade92 said:

Whatever is causing the highlight is definitely coming from outside the room or caused by something funky about the wall. The door and door frame are grouped together in a blueprint. Could that also have something to do with it? The bp doesn't do anything at the moment, but I set it up so I can give the door interactivity later.

Well, this might be the problem in the end, because when you use a static mesh on a blueprint I think it sets the lighting to Movable, therefore that static mesh on the blueprint will receive only dynamic lighting and shadows. However, this can be overriden if you go to the mesh details inside the blueprint and set to receive Static Lighting, from what I remember is here.

THANK YOU!! I've had this problem before but changing the whole object to stationary didn't fix it either so thank you very much for your screenshot! I had no idea that check box existed! Things look much better now!

Obscura

Just wondering but if the thing is movable, changing the resolution of the indirect light cache volume should fix it? Try increasing the parameters of the volumetric lightmap in the world settings. This IS a real solution if it works unlike the light as if static checkbox. That checkbox makes a movable mesh using lightmaps but an opening door shouldn't do that. It should interpolate in a volume which volumetric lightmap was made for (indirect light cache earlier). It makes a grid of points with the values of the indirect light so when the mesh clips/ moves through the volume, it will recieve correct indirect lighting. Its essentially a voxelized light volume.

Alanandrade92

Obscura said:

Just wondering but if the thing is movable, changing the resolution of the indirect light cache volume should fix it? Try increasing the parameters of the volumetric lightmap in the world settings. This IS a real solution if it works unlike the light as if static checkbox. That checkbox makes a movable mesh using lightmaps but an opening door shouldn't do that. It should interpolate in a volume which volumetric lightmap was made for (indirect light cache earlier). It makes a grid of points with the values of the indirect light so when the mesh clips/ moves through the volume, it will recieve correct indirect lighting. Its essentially a voxelized light volume.

Sure, this is the best approach if the door will move. Thank you Obscura!!