Correct way to lightmap?
Hi there, I am fully aware of the many, many tutorials, questions and tips out there to finding the correct way to lightmap but these methods either aren't working for me the way I feel they should, or i'm missing something crucial.
I have many models but for this question I'm going to use this specific one as my example -
This model is fairly complex despite its lowpoly style and for it to look half decent in UE4, it needs to be correctly lightmapped.
It has a texture UV which is done in blender with a simple "Smart UV Project". Nothing fancy, just gets the faces on my simple texture. Here is a screenshot of what that looks like -
Now here is where I feel the issue is. I created a second UV map for the lightmap which, when unwrapping, I use "lightmap pack". What I don't know is the correct image size i'm supposed to use or the margin. Heres what my lightmap looks like and the settings I have. (Once the uvs are unwrapped I use Ctrl-A, and Ctrl-P to separate the faces and add space between them) -
Now in UE4, I always seem to need a high lightmap resolution. some lighting issues don't go away unless I put up the LR as high as 1024 which i generally try to avoid doing as it seems to me to be unnecessary for such a model. I have used the other method of generating a lightmap through Unreal. this is still followed by the same issue. In general, my question is - Am I doing something wrong? Is there something I'm not seeing? Please help in any way you can without just sending me to some site I've likely already been to. Thanks for the help in advance. :)
asked Sep 07 '17 at 08:06 PM in Using UE4
There is no unified "proper" way of unwrapping for lightmap, but there is a set of guidelines and recommendations.
In your particular case, generated lightmap UVs seem quite impractical for given model. Use much lower number of separate UV islands. For example, whole outer surface of the log can safely be a single UV island. As for knowing correct lightmap size in advance, well of you can either approximate it in advance, eyeball it, or rely on UE4's lightmap packing.
answered Sep 07 '17 at 09:41 PM
Reviving this - I've done a lot to lightmaps since this post and am still having trouble. Here is a different model to show how I've used seams and such to unwrap a model and the result -
The model - Simple in design but a pain none the less. - ![alt text] and the Lightmap - ![alt text]
Now I thought that the lightmap i had prepared would be fine. it had padding and was within the bounds and uses as few islands as possible; everything everyone says to do for lightmaps. Here is what it looks like in UE4 however - ![![alt text]]
bear in mind that the lightmap resolution for this object is set to 512. : /storage/temp/224669-tree-image.png : /storage/temp/224670-blender-uv-image.png : /storage/temp/224713-screenshot00009.png
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