Texture precision

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  12 December 2004
Texture precision

Something that have been baddering me with textures mostly (Decals with alpha) is that they can look great from far away, but when i get up too close they are horrible and loose a lot of precision. So, an example, i made the decal of this ship saucer with a .tif of 1024x1024. The saucer is 106m long, etc...The vectorial design was made into illustrator and then export to a jpg. The alpha and tif was generated into paintshop pro.

Up close:


Far away:


Is it the format of the picture, it's size ? Or is this a rendering problem or settings ? Been lost with this problem since a year now, and quite frankly i don't know what to search as a base of solution.
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  12 December 2004
Are you applying a material with alpha to make holes in the ship? And does the ship hull has thickness.
If it is so, it's got nothing to do with precision. What seams to be happening is that you see the hole on the front surface and the hole in the back.
Materials with alpha can't make solid holes in geometry, it's like drilling an empty can of coke.
 
  12 December 2004
No the ship has thickness. Let me explain how the textures are applied. There a main texture (White with panels and patterns) mixed with an underlying big rust texture. Some bumps and luminance is applied to it. Now i want to do a different lines overlay on this (Which i call a decal), so i make it with the UVW of the saucer in the bagkground in illustrator. I do the alpha stuff and all...Let called that tif texture "decalup"

I go back to the saucer and make a polygon set of the area where i want the overall texture to be. I create a new material, applied it to the object and the set's name. I adjust it accordingly. It's working fine this way. I got decalup with an alpha, that you can see in my pictures, that is over the main texture. This way i can adjust and modify each textures to my liking afterward, without having only one UVW texture.

The problem is that decalup once i get too near, generate a fuziness into the lines. It doesn't have the clarity of the main texture. Not sure if i explain this well...
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  12 December 2004
your texture resolution simply isn't high enough. when you're close you're zoomed in on not just the model, but the texture.

the fact that you used vector lines to draw the original has no bearing on this as you're using a bitmap of them.

if you want to use vector artwork then i suggest importing the lines into cinema as a spline and using that spline in the spline shader (can take quite a bit of work to get right, but it should then be resolution independent).
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  12 December 2004
Originally Posted by mdme_sadie: if you want to use vector artwork then i suggest importing the lines into cinema as a spline and using that spline in the spline shader (can take quite a bit of work to get right, but it should then be resolution independent).

??? Very first time i heard of this. Is there a tutorial somewhere that can show me how to use this method ? It sounds interesting.
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  12 December 2004
Your texture resolution is too low for a close up and even at 4096 it won't be enough for a large model. I would suggest breaking up your UVs to multiple UV sets of 4096 or whatever you can handle for different parts of the ship. There is a tutorial on Maxon's site on sort of creating Multiple UVs, though they should really support Multiple UVs via UV space, instead of this workaround.



Cheers,
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  12 December 2004
What also helped me a great deal in trying to get lores maps to look higher res is not using MIP mapping but SAT mapping. In every channel of your material you loaded your texture map into, set it from MIP to SAT. It isn't the holy grail of making your textures look 1000 times better, it does add that little extra edge , for human skin it works great for example.
 
  12 December 2004
I took the suggestion about sampling and fiddle with various settings. Finally i think that even tho it is fuzzy, using Alias 3 was a fair solution:



At least the line hasn't the "pixel's stairs" in them when you are up close. And they still retain the original quality far away. It's a bit transparent but it's the luminance and bump texture that seems to influence it.

I could have done all seperate UV, but that object has already 6 textures on it, so i tend to find the interface for managing those textures for the object a bit confusing. But maybe for the rest of the ship i won't plug a big piece of decal like that in one piece...

A question tho: Does R9 support psd files now and especially it's layers and alpha channel ? I think i read it was the case...I wonder if it's not the antialiased option of paintshop pro that didn't stand up, and maybe doing a psd file with an alpha channel would have been more precise.
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  12 December 2004
Originally Posted by dubeau: ??? Very first time i heard of this. Is there a tutorial somewhere that can show me how to use this method ? It sounds interesting.


It's covered in the 8.5 Addendum PDF.
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  12 December 2004
Originally Posted by mrblifil: It's covered in the 8.5 Addendum PDF.

Thanks. I hate reading pdf file...Why can't this software manage to have a real help .ch system (Just like windows), which allow context and word searching. I will try to read it, that is if i got the patience.
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  12 December 2004
- make your texture higher-res (e.g. double the resolution)
- go into render-settings and set mip-map level in the Antialiasing menu from 100 to 0. The default setting is totally useless unless you're doing broadcast graphics. softens the crap out of all textures.
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  12 December 2004
Originally Posted by dubeau: Thanks. I hate reading pdf file...Why can't this software manage to have a real help .ch system (Just like windows), which allow context and word searching. I will try to read it, that is if i got the patience.


What version of Acrobat Reader are you running? The latest version has very robust word search capability. I wouldn't go to the C4D manuals without it.
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  12 December 2004
Originally Posted by mrblifil: What version of Acrobat Reader are you running? The latest version has very robust word search capability. I wouldn't go to the C4D manuals without it.

6.0...that must be the last one. Maybe i never actually saw the feature...
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  01 January 2006
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