Resizing textures

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Old 05 May 2013   #1
Resizing textures

Hi--

I'm a real novice at texturing polys using bitmaps. I'm subscribed to Lynda and have learned quite a bit, but haven't seen this topic addressed yet. Meanwhile, I'm hoping someone can give me some practical advice.

In the screenshot below are three rusty pipes in a subterranean environment.

Numbers 1 and 2 use the same exact material, which consists of a 1024 x 1024 .iff file, created in Photoshop, both for the color and bump map. The 2d Placement node has Repeat UV values of 4 and 40 (the overall scale is very large), and the Bump node depth is set at .2. The larger pipe, Pipe 1, is simply a proportionally scaled-up duplicate of Pipe 2.

Pipe 3 is a duplicate of Pipe 2, but length scaled to about 25%. It is mapped to a duplicate of the material network applied to Pipes 1 and 2. However, in order to match the appearance of Pipe 2, I had to change the Repeat UV values to 2 and 4 and the bump depth to 1. This was strictly a matter of trial and error, trying to guess what would work.

Three related questions:

1) Is there a way to use the same material on two similar, but differently-sized, objects without having to rescale the materials, or must the placement nodes be tweaked on a per-object basis?

2) If the latter is the case, is there some approach that will work better than my trial and error method?

3) Thirdly, I can sort of see the logic in having to tweak the coverage numbers, but I'm baffled by the need to change the bump value.

All help or suggestions very much appreciated!

--Tim
 
Old 05 May 2013   #2
What you want to look at is the uw mapping.

You could have to objects that looks just alike polygon vise but you could scale the uvs of whatever object you want, then you can assign the same material and it will receive a different scale so to say.

just create a regular polygonplane and try some different uv mapping on it. assign a lambert with a checker texture so you can easily see whats happening when you change stuff.
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Old 05 May 2013   #3
And remember to turn texture filtering off for foreground objects, also set multipixel filtering to mitchell and you'll get more detail out of your texture.
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Old 05 May 2013   #4
If you need to keep scale relative to all your objects, consider UV-mapping them into the same space. For example, say you had a scene with a bunch of such pipes? Combine them, then run an autoUV on them, and they'll all be (roughly) proportional in the UV map and the textures should lay out this way too. Granted, this doesn't work great for round objects but that's the basic idea.

Really, so long as your UV maps are proportional to each other, this won't really be a problem for you.
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Old 05 May 2013   #5
Originally Posted by InfernalDarkness: If you need to keep scale relative to all your objects, consider UV-mapping them into the same space. For example, say you had a scene with a bunch of such pipes? Combine them, then run an autoUV on them, and they'll all be (roughly) proportional in the UV map and the textures should lay out this way too. Granted, this doesn't work great for round objects but that's the basic idea.

Really, so long as your UV maps are proportional to each other, this won't really be a problem for you.


Good advice. Personally I feel a bit unsure using automatic uv creation unless I'm using zbrush to texture. Even then I would prefer to concentrate on unwrapping one static, or pipe in this case, then scaling uvs for duplicates.

If op is looking to dup and scale the object and uvs automatically, then someone should write a script!

OP check highend.
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Old 05 May 2013   #6
Many thanks for the excellent advice! I've been trying several of these approaches, and feel like I've learned a lot.

A related thing I picked up (not addressed in my original post) was the issue of continually having to adjust the Repeat UV channels in both the color map and the bump map as I experimented with the texture placement. However, I found the answer deep in the comments section of a YouTube video on texturing. I pass it on here, but I'm sure you guys already know about it--connecting the placement nodes of the respective maps via the connection editor. That way they stay in sync.

Thanks once again for the helpful advice and guidance! You guys are great!

--Tim
 
Old 05 May 2013   #7
Brilliant idea with the connections of the place2D nodes! Don't know why I never thought of that, but I've been doing all of mine the manual way for years. Thanks!
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Old 05 May 2013   #8
Originally Posted by InfernalDarkness: Brilliant idea with the connections of the place2D nodes! Don't know why I never thought of that, but I've been doing all of mine the manual way for years. Thanks!


My pleasure. Wish I could say I thought of it myself, but as I say, it was buried deep in a comment thread on Youtube.

Anyway, it's a good feeling to be able to contribute something useful now and again, rather than just coming up with dumb-ass questions--of which I have aplenty.

--Tim
 
Old 05 May 2013   #9
Placement nodes

U probably want to just delete the placement nodes for bump and or spec maps etc. In the shader network and then connect just the diffuse color placement node to those maps so you only have 1 for the whole network.
 
Old 05 May 2013   #10
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