Building UV Unwrapping trouble

I’m trying to texture a building asset in Blender, however I can’t figure out how to get the UVs just right for Unreal. Unreal has been a bit wonky for me when trying to import objects but I managed to figure it out for simple objects which could be easily projected from view and adding a 2nd UV channel for the lightmap. But for a pretty complex building I don’t see how to easily unwrap it. I’ve tried and can’t seem to figure it out. Every unwrapping tutorial I can find is of a cube or another simply unwrapped object, so I would greatly appreciate some pointers. Is Blender just not good for Unreal? Should I try to learn Maya?


Edit: Colors on the building are just the different materials.

Blender is the application for UVs bar none, Maya is much more of a pain… That being said I don’t really know if the lightmaps are your issue or not, I just don’t know the game engine that well.

BUT UV mapping can be difficult, its mostly trial and error.

Assuming you understand the very basics of texture coordinates, the idea when Unwrapping UVs is to create seams along the more hidden and out of sight edgeloops.
You define seams to map the UV islands, and Blender does all the rest flawlessly(99.99% of the time). Provided all of your intended islands have marked seams around their perimeters and their aren’t any overly complicated shapes, or shapes that run in a circle (i.e. the walls of your building in a continuous UV island around your buildings perimeter would be unable to make the 2d UV faces area the same as the 3d polgyon faces along the height of the building as the UVs would be forced to expand radially from the center)

After a little bit of fiddling around, I managed to get it sorted to one UV

However, since the building will be large it’s going to need a pretty high resolution and using the UV that I have now would force me to use a very large picture size to get the resolution I want. My question is: is there anyway to have multiple UV layouts so I can have things sorted out easier and smaller file sizes? Or am I just wishing for too much here?

ex. Brick walls file contains only the brick wall faces and Glass file would only contain glass faces.

Yeah Blender is a good UV’ing tool - you should try C4D sometime :wink:

It’s a skill you have to learn to do game art. Look for Blender tutorials where you select seams etc.

What you need to do is not expect to unwrap the whole thing in one go, you need to select parts and build up a UV map. You could do nice flat UV’s for all the fronts (around the door and windows) but you should select the inner arch for instance and do that as a separate island.

Saw your second post. you should only really have 2, one for the texture(s) and one for the light mapping. the Lightmapping one is more like the unwrap you have there but you should try and repack it better - I think Blender has some packing tools.

To get better texture resolution, people tend to make things more modular. For instance your building facia there might be made from two modular pieces. So you’d do a “window” piece and a “door” piece and texture those up appropriately. You might also consider tiled textures in parts too.

There’s no magic to this though, go to any 3D tutorial site ( and learn.

Funnily enough im the complete opposite, Maya is simple and efficient compared to blender… at least for me, I’ve had varying success with blender in terms of the UV mapping just doesn’t work properly when exporting then importing. Compared to maya (which I’ve yet to have a single problem with).

Uv mapping proper for textures is completely different to setting up a UV map for light map, this is something you need to remember from the get go when setting up your UV sets. Uv mapping for textures is usually about trying to keep the lowest amount of islands and splits and to maximise the area. When it comes to light map UV’s you need to need to take into account of the effect you have on the light map when splitting uv’s into separated islands.

Example for a light map uv on a 90 degree angle, normally for a texture it wouldn’t matter if those were joined (and for something like a wall it would be beneficial to join them as it would give better continuity in the texture) but for light mapping UV’s it can have different consequences as the light can bleed from one angle to the next because they are joined with no space it can end up looking weird.

Hi Hydrolexo,

There are definitely some good suggestions in here to get you started.

Something also to consider when building larger environment pieces like a building a good method to use would be modularity. One of the first modular tutorials I worked with was from 3D motive using UDK for a modular building. Tyler Wanlass goes through a whole process showing you how to build your assets layout the texture for the highest UV resolution by using a tiling texture. Using this type of method for texturing will give you the greatest resolution for your your uv space and keep from having to have such a large texture to make the object look great.

As everyone above has also mentions lightmaps are a very important task to set up when using Unreal. If you’re using a dynamically lit scene then, yes, you don’t need them, but if you are using static lighting you will absolutely need these to make your model look great!

Some tips and tutorials on setting up lightmaps (these are not specific to a particular software necessarily, but the concepts should help get you started and you can always ask questions when they arise):
While some of these reference UE3/UDK the concepts and theory is the same.

Epic’s Lightmapping documentation

World of Level Design - Lightmapping common problems and solutions

World of Level Design - Techniques and how to create a second UV in Maya (I know you dont have Maya but some good tips included!)

Hourcences - Lightmapping Basics

I hope this get’s you a good head start.



I think I am going to go with modularity as you said. From what I can tell it seems like the answer to my problems and it will save me a lot of work-load for future models!

Hi Hydrolexo…
I can feel the pain you are suffering…! :frowning: and Really wish if there is a plugin for Blender for texture baking.
I had never tried Blender, and don’t know if you can export your work from Blender to 3ds Max OR Maya, just for unwrapping and import them back to Blender…!!
My suggestion is to try one of the following:
_ Flatiron for 3ds max
_ Unwrella for both 3ds max & Maya.
Since I had tried Flatiron I encourage you (in case you know how to use Max) to try the Trial version for 3ds Max, it was very helpful for me :slight_smile:

Best Regards

Two main things to note when creating large single mesh buildings or tiled multi texture objects.

The Building or Object can be approached in two ways.

1.Skinned Ie uses a single texture map either made by hand or baked via various 3d apps (this will give poor resolution on various parts of the model or require a huge texture map)

  1. Groups/Child meshes
    This is by far the best method, Constructing your mesh and breaking the faces up into Brick,Stone,Wood,Glass groups ect would allow you to have separate materials for each which allows Tiling Textures and a model resolution far beyond the skinned single surface without hitting huge texture limits.

If you use 3DS Max then you should try the TextTools by Renderhjs…]( script.
Its got everything under one roof, its donate-ware and it works in Max 2014 too.
UV-ing for textures and lightmap channels can be a pain when your starting out :mad:, but tools like this really help take the edge off of it IMO…:o

Good luck on your UV adventures…:slight_smile: