Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

Black area on mesh - lightmap?

Hi all,

I ve a problem with a mesh in Unreal Engine 4.7.3

I ve a strange dark area on left of the mesh ( in red, on pic )


I tried :

  • lightmap 64 - 128 - 512

  • reset Xform - Reset Normals

  • few different unwrap ( flatten, unfold etc... )

  • checked Ngone

  • reset Smoothgroup

But i've still this bug.

Somebody have any idea please ?


Product Version: Not Selected
more ▼

asked Mar 26 '15 at 04:19 PM in Rendering

avatar image

26 4 7 9

avatar image KrunkFu Mar 26 '15 at 07:40 PM

Is there a texture? What is the wireframe like? Can you show us the UVs?

avatar image Alec- Mar 26 '15 at 09:25 PM
avatar image Alec- Mar 26 '15 at 09:27 PM

and no, just basical material in 3DS, and Floor Material il UE4 No texture

I checked with a simple box, and I ve no problem. The problem from mesh or uvs.....but I don't know where :/

avatar image KrunkFu Mar 26 '15 at 09:48 PM

Could you provide a dropbox link(or whatever service you prefer) to the fbx for this mesh so I can try to replicate this on my end. I can't see anything that would be causing that kind of shading and now I'm really curious.

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

2 answers: sort voted first

I imported your model into ue4 and applied the basic material and this is what I got. alt text

Everything seemed to work fine. No weird shading or anything. I checked the mesh in blender and maya and saw some weird geo so I cleaned it up and made it more low poly (you can bake your high res to it) and I also set it up so that you can vertex paint on it if you want. I UVed it and added a second UV set for lightmaps.

Import my mesh and see if it fixes anything. https://www.dropbox.com/sh/yfp3zvqfc8qkw5q/AAAfbMDmJZeaZeArWZOXs_aWa?dl=0

(you might see a small seam down the front of the object if you zoom in. This is caused by the first UV set is mapped.)

Let me know if the new mesh fixes anything.

worksfine.jpg (17.0 kB)
more ▼

answered Mar 27 '15 at 03:01 AM

avatar image

218 13 12 24

avatar image Alec- Mar 27 '15 at 09:10 AM

Hey Krunkfu ! It works !

But 3 things :

  • the first mesh was more high poly, the wire was good, no ? ( without Ngone just full quad and tri )

  • your new model is very big !? do you scaled it ?

  • how do you unwrap a second uv set for lightmap ? what is wrong in my inital mesh ?

Thanks :)

avatar image KrunkFu Mar 27 '15 at 07:19 PM

Your mesh was at 1700 tris and mine was at 398. There really isnt any difference between them in terms of how they look in game so there was a lot of wasteful geometry. I saw some verts floating in the middle of an edge that didn't seem to be connected to anything but other than that I didn't really check for non-manifold geometry.

Your model was tiny when I imported it so I scaled it up. If you scale mine by 0.1 it should get you back to the right size.

It depends on what software you are using. In blender you just go to the UV Maps panel under Object Data. In maya it can be found under the polygons menu in the UV editor.

What was wrong with your initial mesh was the unnecessarily high polycount as well as some strange geometry(random verts hanging around an edge). The grid you can see in my wireframe is so that you can vertex paint. It doesn't change the look of the mesh and considering the new mesh had less than 1/4th the tris of the original even with the added geometry for vertex painting it would be considered pretty optimized assuming that mesh was some kind of wall piece and not a tiny decoration item.

This just occurred to me but do you have anything overlapping in your light map? The only other thing I can think of would be to scale your uv maps up a bit and increase the spacing between the different UV islands.

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

I tried to set a second UV chanel for loghtmap. My Dark area is still here, but smaller. It's better, but not perfect :/

more ▼

answered Mar 27 '15 at 01:19 PM

avatar image

26 4 7 9

(comments are locked)
10|2000 characters needed characters left
Viewable by all users
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question