Learning UV Mapping - Interior wall challenge

[Indigo Mertel]

I have received some good advice from all of you 3d wizards in a previous thread (What's the best topology?) for the conversion of a prim-based villa to mesh while at the same time trying to learn  Blender. The modeling part is coming along pretty well and I am getting more confident with the program. I am now trying UV Mapping. The exterior walls, ceilings and floors were not a problem. I do have a problem with the interior walls.

The image below shows a section of the ground floor, each color represents a different material in Blender.

I have to map a different textures for each material. The textures have different color but the same pattern. Here is an example:



The texture has moldings, so it must match the height of the wall and must repeat for its length. I am not sure what the best approach to do this is. One solution I tought of is to create one new image 1024 x 512 in size in the UV Editor for each wall section, with some optimization for the shorter segments. Then, for each UV Map I would scale the island so that i takes all the UV Map space. Is this correct? Do you have any suggestion?

BTW, can anyone tell me what the dotted orange box around the origin point at the lower left corner of the building is and how I can get rid of it?

Thank you in advance for any advice you can offer.

[Cale Flanagan]

If you want the wall in a continues way, meaning repeating and wrapping around the corners, try unwrap follow active quads (you need one face active), currently I'm not sure if this works with your trigs.

Another way is to wrap project from view (no bounds) with selecting the walls one after each after and always stay in the same zoom level (gives same sizes), then later mount the groups of faces corner to corner in the UV editor. Then you only need to scale so height is right.

Just my thoughts:)

 

[Kwakkelde Kwak]

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Indigo Mertel wrote:

One solution I tought of is to crate one new image 1024 x 512 in size in the UV Editor fo each section of the walls, with some optimization for the shorter segments. Then,for each UV Map I would scale the shell grid so that i takes all the UV Map space. Is this correct? Do you have any suggestion?

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You can keep the original texture and its size without any problems. You do not need seperate textures or materials for your walls either, except for the ones you want to colour differently. Not working with Blender it's a bit difficult to explain, but I'll give it a go.

What you can do is overlap your UV islands (different wall sections) if a wall is 4 meters high and 8 meters wide, let half of the UV for that wall stick out of the texture in UV mode. The texture in UV mode is repeated infinitely, so that way you will get a 2x1 repeat by default for that section (SL will show 1x1). If the wall is 2 meters wide, make sure the UV island only covers half the texture you see in UV mode, etc.

You can overlap as many walls in the UV as you want, or place them next to eachother.

Maybe some Blender user can explain it more detailed, including all the buttons to click .

 

[Indigo Mertel]

Thank you, Cale. I am quite new to Blender so I need to ponder a bit on what you suggest as I don't fully grasp all the details. I'll come back if I'll need more help...

BTW, you touch another topic where I am confused. Gaia Clary suggests that working with quads is easier for UV Mapping. Does it mean that I should triangulate faces after I UV map? Doesn't that break the UV mapping?

[Indigo Mertel]

Can I really overlap and let the islands stick out?!? I have seen tutorials stacking up islands but my understanding was that the islands had to be of the same size. And I didn't know that I could let the islands stick out. This would make things a lot easier.

[Kwakkelde Kwak]

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Indigo Mertel wrote:

Can I really overlap and let the islands stick out?!? I have seen tutorials stacking up islands but my understanding was that the islands had to be of the same size. And I didn't know that I could let the islands stick out. This would make things a lot easier.

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Yes not a problem, you can make one long wall in your UV thing, where only a fraction actually is on the texture. Like I said, you need to imagine the texture repeated infinitely in every direction. I wouldn't be surprised if Blender has the option to show that in UV mode, I know 3ds max has the option.

Like Cale said, all you need to do is make sure all walls have the same height in UV mode, the height of the texture. So scale your islands uniformly (is that a word?)

What you most certainly cannot do when you UV map your item this way, is baking (light/occlusion)) textures.

[Indigo Mertel]

Great! Thanks a lot. I had no idea I could do that. And, yes, I did see a tutorial showing the texture repeating in every direction.

>> What you most certainly cannot do when you UV map your item this way, is baking (light/occlusion)) textures.

Do you mean I can't when I need to bake light and occlusion maps? In theory this is not a problem in this case as I can generate those maps with an external tool (I use ShaderMap, really cute tool).

[Kwakkelde Kwak]

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Indigo Mertel wrote:

 

Do you mean I can't when I need to bake light and occlusion maps?

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Yes and no.

If you want your moldings to have some occlusion effects, you can single out a piece of wall that covers the entire texture, then bake. If you have stacked UV islands, that won't work, because Blender will get information from all the overlapping islands and will try to stack the occlusion on the single texture. That will give horrible black spots.

So make sure you have a texture with occlusion before you start stacking UVs.

With light effects like baked in shadows from other objects, it will not work at all, unless various pieces receive the exact same shadows. Still you need to bake without any overlap.

 

[Masami Kuramoto]

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Indigo Mertel wrote:

The texture has moldings, so it must match the height of the wall and must repeat for its length.

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I'm surprised no one has suggested cube projection yet.

Select the walls, press U, choose "cube projection", adjust the "cube size" parameter until the texture starts repeating at the top edge of the wall. This is best done with a UV test grid and with the 3D view in textured mode, so that you have instant feedback. Holding shift while dragging the widget will increase/decrease the value in smaller steps. When done, move the entire UV layout 50% down. Now the top and bottom edges of the texture should be aligned with the top and bottom edges of the wall, while repeating horizontally and maintaining the original aspect ratio.

[Nalates Urriah]

I am not sure I undersdtand what you are trying to do. So... I'll ramble a little in the direction I think you are asking about.

The UV layout for walls, exterior or interior, can be stacked. If you use UV Unwrap -> Reset, all the polygon's UV polys are stacked on top of each other. Fortunately only the selected polys will have their UV polys reset. A single texture will cover all the polys that have their UV poly on top of it. This is ideal for seamless textures. It is also a good way to provide more pixels to the surface without increasing the download or texture memory use.

You can't generally get away with stacking UV polys, if you want to bake ambient or other textures. Their are advanced baking processes that will let you bake more complex Blender-multi-texture mappings with outputs to ambient or other maps.

You can select various surface polys and unwrap them to different Blender-UV-textures. You do not need to use all UV polys in each UV-texture. Those that you do not want to bake into or use the texture, place off the UV-texture image.

Blender will let you specifiy numerious UV Maps for an object.

----The box... if you mean the box in the image, it looks like an object. If you are having trouble selectnig it, you can try selecting all (A-key) and then manually deselect everything you want to keep. See if you can make it go away that way.

Hope this gives you some ideas.

 

[jamie Cheeky]

Not so hot on texturing so cant help you out there .....but the orange box looks like another mesh object in your scene.  If its joined to your existing item you have prob added a new mesh box whilst in edit mode rather than object mode - so you would need to unjoin it first (shortcut p) then delete it - but please please save before u try this as I would hate for you to lose all of it - if you add items whilst in edit mode it becomes part of the same mesh and not seprate hope that makes sense ?...however if you added it in object mode and its independant of the other mesh then simply delete it.