Hello everyone, i am working on an architectural visualisation and i have designed a crate in 3DS max as a test for importing objects and materials into unreal engine 4.0. The issue is shown in the images provided, i created
and unwrapped a texture in 3ds max and edited it on Photoshop to place on the crate and it looks fine in 3DS MAX. However when i import it into unreal engine and press build i get some random black shades on the texture, effecting the textures original look.
I have tried updating light map coordinate index to channel 1 and it helped a lot but i still see some black shades on the texture. Does anybody know what i am doing wrong i have provided the file of the crate in FBX and 3DS and also a few images to show you guys. i been trying for days to figure out the problem! If someone can help it would be very much appreciated !
I was able to import the FBX into UE4 and take a look. However, the max file was made in a newer version (2015?) than I currently have, 2013.
Looking at the FBX though. I opened up the mesh in the mesh viewer and there isn’t a second UV that is used for lightmaps. This should have thrown a warning that you have overlapping UVs when you build lights. This is going to bake information for lighting wrong for the mesh.
You may have already done this in the Max file but i was unable to test this.
Once you get a second UV created and it is assigned to the UV light map coordinate index 1 you may want to adjust the lightmap resolution up form the default 32 to 64 or 128 for crisper shadows.
Let me know how this turns out and I’ll help you along if you have any questions.
> Looking at the FBX though. I opened up the mesh in the mesh viewer and there isn’t a second UV that is used for lightmaps. This should have thrown a warning that you have overlapping UVs when you build lights. This is going to bake information for lighting wrong for the mesh.
By ‘mesh viewer’ you mean inside of UE4? And by second UV you mean to go down under details and create a new UV map on channel 1?
> You may have already done this in the Max file but i was unable to test this.
You can do this in max?
> Once you get a second UV created and it is assigned to the UV light map coordinate index 1 you may want to adjust the lightmap resolution up form the default 32 to 64 or 128 for crisper shadows.
Really would like to see some more streamlined guides on how to do this stuff. Lightmaps is new to me and probably a lot of us. In fact I’d like to just learn more about the term “lightmap” itself, and reading a lot of the tutorials aimed at UDK just didn’t work for me.
Hi , thank you for the help and advice. I have tried what you suggested as in creating a second channel in 3DS max and the mess on the crate cleared up most of the random black shades on the box. But there still was some parts of it which had black shades.
I have gone ahead and created walls which could show my problem a bit more clearly and is more relevant to my profession (i have attached a link to this for 3DS max 2013). I have created a 1st and 2nd channel in 3ds max for my wall group and exported it as an FBX. When i build the light the same problem as the crate occurs but after updating channel 1 in unreal engine the texture is cleaned up but there is still alot of black shades (as shown in the images). I am not sure what the issue is but i do notice my second UV mapping change in shape after i press build (i have provided a before and after picture).
If you could please take a look and help it would be much appreciated!
The labeled 1 is the mesh you provided with the above FBX. I didn’t touch a thing on it other than adjust the lightmap resolution from 32 to 64 to smooth out some of the edging.
In the one labeled 2 - this one I did what I believe you may have done. I imported the FBX then opened this in the mesh editor and chose to auto-generate lightmap for UV channel 1.
The result was the bad shading and the change in the UV channel 1 that you showed in the images above.
When you import a FBX that has the two UVs already setup in Max UE4 will go ahead and assign the second UV as the lightmap. There is no need to generate one at this point.
The only thing you would need to do is change the lightmap resolution for the mesh to get crisper shadow edges. Changing it from 32 to 64, 128, 256 should work out fine for this mesh. Since it is a larger mesh, having a higher lightmap would probably work better for this.
If you still have questions feel free to keep asking!
Hi , you were right it fixed most of the problem on my wall. However I think i figured out what my next issue is, it is the second UV channel in 3DS max that is causing the random shades to appear. I don’t know how to set up the second UV channel properly, i have given the polygons in the 3DS max UV editor enough space so that there should not be a lighting issue while also expanding the sizes of the polygons to increase shadow and light quality(i assume ive done it correctly).
But in some parts of the walls there are still issues with the shadows and lighting. I have a video of me exporting the FBX files just so you could double check i am doing everything correctly as you suggested in the previous comment. (This video also shows some of the issues with the lighting im facing towards the end)
If the issue here is the second UV channel in 3DS max, how would i go about fixing the arrangement of the polygons in the second UV channel. What are the steps to make sure it is done correctly to prevent this problem from happening. Thank you in advance !
A good way to think about how the lightmap resolution works is here: (64, 128, and 256)
Now if you think about your lightmap UV and how it’s laid out, you can imagine that any of those smaller pieces (especially the sides) will hold more shadow than light. This is why they are coming in blackened like that. If you up the resolution those smaller pieces can use more texture space to bake it’s lighting onto.
I hope this helps.
If you’ve still got questions feel free to keep asking!
