Lightmap/2nd UV Channel issue (Probable Fix)

Hey guys, so I’m having an issue with the models I import into UE4.

I figured that the problem I’m facing is with lighting (Which I made sure of, because I turned unlit mode on and the textures appeared perfectly, but obviously there was no normal map to be seen because of the lack of light).
So I searched here and there and actually added the secondary UV-channel, but I’m not sure if I did it correctly. I had my UV’s made in zbrush, then imported my model into 3dsmax, then I added the Unwrap UVW modifier, added a channel, saved my original UV map, loaded it into the 2nd uv channel, selected inverted polygons then packed UV’s, and this was my result.
From this : to this

I’ll show you a comparison of what the model is supposed to look like, and how it looks like in UE4.
in Zbrush : -------- When imported into UE4 (This was after I imported it without a secondary UV channel, which in that case had black boxes all around) : and (Other than the obvious shadows on the model itself, there’s a weird shade that changes the color of the texture, I’m really not sure how to explain it, but you can notice it if you compare the original model with the one imported to UE4)

I tried multiple things, I tried importing with calculate normals/import normals, I played with Light-map resolution settings, I tried to export from 3dsmax in different settings, both 2013 and 2014 for Binary/ASCII. I’m really not sure what am I doing wrong here , is my UV-Map *****? Cause I’m a total beginner at this.

I searched all over youtube/google and this forum, but I still cannot find something that will help me out and/or is easy to follow, please if you want to help me out give me steps, don’t expect me to know what you’re talking about because I’m really still a beginner and it would mean the world to me if you could take your time to explain all the steps needed to be taken to make sure I have a good looking model that will actually appear in UE4 correctly.

Well I kind of fixed it guys, I think. If I face another issue in this workflow I’ll edit the topic.

What I did wrong: I skipped mirroring vertically and I had rotate clusters checked, which happened because I tried the exact same steps with an older model and it didn’t work (which now that I recall was because I had **** UV’s)

All the steps required :
You need to have a good UV for the model, if you’re using Zbrush, polygroups and control paint are your friends, general rule : Seams on unimportant locations = Blue color.

Steps required to follow in 3dsmax to create a second UV Channel:
Modifier List > Unwrap UVW > Open UV Editor > Save UV Map in desktop > Increase Map Channels to two > Reset UVWs > Open UVW Editor > Load map which was saved on desktop > Be in polygon mode > Inside UVw Editor, select inverted polygons > Mirror Vertically Selected Subobjects > Tools > Pack UVs > Margin 0.3 FILL HOLES + NORMALIZE CLUSTERS + RESCALE CLUSTERS > MODIFY UV-MAP AS REQUIRED, ENLARGE PARTS THAT YOU THINK ARE IMPORTANT ON THE 3D MODEL, LIKE THE FACE OF A CHARACTER > Right click the Unwrap UVW in modifier list and Collapse to > Export Model as a FBX Binary 2014 with triangulation and embed media.

If I said anything incorrect, correct me please , this is all coming from a newbie.

If somebody can change the topic title to : Lightmap/2nd UV Channel issue (Probable Fix) or something in those lines it would be great, I’m seeing a lot of people are facing the same problem that I faced.

I hope they fix the 3DSM to UE4 issue. Maya/Blender files converted to .fbx work flawless…3D Studio Max files…any format with out having to mess with the UV Maps so much is rather irritating since I like the modeling tools of 3DSM and animation is easier for me via 3DSM. Maya just seems to lack the same tools I am use to though I honestly miss LightWave 3D the most was the first “Full Fledged” modeling/animation set I used and fell in love with.

Okay, this is extremely frustrating!
Today I checked my UE4 project again, and the model is still having this problem :frowning:
Even when I increase the lightmap resolution to 520 (Which I don’t want to do, there must be a better fix) the texture/normal map is still f’d up. , you can see that the black checkers are gone, but there’s still that… :confused:
What am I doing wrong here? Somebody please help!

Your UVMap looks not right to me. I guess there is the problem. You should have two clean circles in your uwmap and not 1000 pieces from the object.
Search for some UVUnwrapp tutorials in Youtube

on this pic:


You were almost there, but you messed it all by packing uvs.

Instead of packing them, select all vertices and weld them together. But watch to only weld vertices that are close together, do not change topology.

Simply put GREEN lines on UV layout are bad unless they separate different areas.
Turn all green lines there (besides outer edges) into white welded lines.

Also keep in mind that distance between two areas (green lines) must be at least 2 pixels on lightmap (or 3) for lighting to have no artifacts.

Edit. also this is simple tube mesh. Apply cylinder UV to it in 3dmax, manually “pack”/move uvs so there is no overlapping.
Import back to zbrush with new uvs and render normal map again on new uv layout.

Oh and follow HOURENCES tutorials about making meshes for unreal engine, they are still valid.

By areas do you mean islands? And I’ve selected all vertices and welded them, this is the result

Yup, now do pack uvs, and you have fine lightmap uv.
You should also get this uv back into zbrush and render color, normal etc maps again for this layout.
Less artifacts this way.

And check hourences tutorials about meshes, you have made more mistakes in your mesh than only this uv layout.

Alright I’ll check hourences and thanks for the help. (Can you point out any obvious mistakes I’ve done?)
Lastly, this is the result I got , and isn’t the normal map/texture map supposed to be in the first UV channel? I don’t understand how will I connect the newly made normal map/texture map with the 1st UV channel (I usually do it through the content browser ) , since it’s different than the rendered out UV’s texture/normal map. see this is the 1st UV channel , or am I totally misunderstanding something, sorry for the noobiness.

As i told you allready. You got an round object, so your uvmap should be round too.
Like this one here.

I see you have 3d max. And probably ZBrush.

Your workflow should be different.
First you create LOW poly mesh in max, for Your disc you should create cylinder with 18 or 24 sides, 1 segment for height.
Convert it to poly, chamfer top and bottom circle edges, or extrude those surfaces, unless you want hard edge there. For soft edges its better to have at least 45deg there (not 90).
Replace those bottom/top circles with quads. I do it manually, just delete them and use bridge to create nice polys.
When you have 3d mesh, set its smoothing groups, then make UVs (use cylinder mapping, then edit/move uv islands a bit to use most of 1uv space.)
If done right usually you do not need second UV for lightmaps.

With nice cylinder that has Uvs, go to ZBrush. Subdivide it and add details. Render all normal, diffuse etc maps.

You done, import all that into unreal.

Ps. Substance designer has best/easiest rendering of normals, ambient etc maps. And unreal will probably have support for its materials anyway.
And its great (fastest to make) for hard surfaces.