When I build lighting I seem to have black sections all over my imported models.

Development Rendering
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I remember this being an issue before on Unreal Engine 3. but all I had to do then was increase the lightmap resolution and it resolved the issue. is it something similar? I cant seem to find a setting that could be the cause of this. Any information on this would be great.

I have seen a few similar situations but the ones I have looked over doesn’t really relate to mine. its now an issue on almost ALL the models across the whole environment.

Thanks in advance.

2

What you’re describing is related directly to your lightmap. Not specifically to the resolution though.

When you build lighting there may be a warning that your meshes have overlapping UVs. This means you’ll need to make a second UV for your lightmap information to be stored. This is exactly the same as it was in Unreal Engine 4.

If your mesh does not have any overlapping UVs the uv spacing between pieces could be too close causing shadow bleed as well.

Ultimately, you’ll want to setup a second UV for all your meshes, so long as you’re using Static or Stationary lights.

This can be done by creating the second UV in your modeling program or by auto-generating one within the mesh viewer/editor (would recommend this one not be used for complex geometry though).

For more information about creating lightmaps and how they can affect your model take a look at World of Level Designs in-depth tutorial series.

If you want to increase your lightmap res and see if that helps out, which it may, you can do this with two different methods.

  1. you can go into the mesh viewer/editor for the selected mesh and in the details panel to the right change the lightmap resolution form 32 to something higher (stick with a power of two: 64, 128, 256)
  2. you can change it for the individual mesh in the viewport in your scene. This only affects the single mesh and not all of the instances of this mesh. In the detail panels look up lightmap and you’ll be able to override it.

On a side note, if you’re having to keep upping the lightmap resolution higher and higher you may want to adjust the lightmap UV to get a better lightmap with a lower resolution.

If you are still having any trouble or have any questions feel free to ask and post any pictures for reference for more detailed feedback. :slight_smile:

Thank you!

Tim

3

I tried the basic method. but I am guessing all I can do is the proper first method you suggested. I never really got into 3D modelling so I get my models from Turbo Squid. I don’t really know what I am doing with the UV things and what not. But I will do a bit of research and see what I can do. Thanks for the Advice! :slight_smile:

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No worries. If you have any questions about your UVs feel free to post them on the AnswerHub or the Forums.

I would recommend being careful with anything you get from modeling sites. The reason being that a lot of these sites recommend that users make their assets as cleanly as possible. This is not always the case with some models not being UV unwrapped and the modeling techniques used leaving ngons and general bad geometry.

Just something to be aware of when using these sites. A lot of their models will more than likely require cleanup to be game-ready.

Tim

5

Thanks for the information. I know what you have mean. I have Experienced a lot of trouble with them. you do however get SOME good ones. Rarely though. as you pointed out. they do need a lot of work before being game ready. I don’t have any friends who are good 3D modellers and Texturers so it makes it difficult to get my projects of the ground as fast as I would like. :frowning: