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Would you mix translucent and solid objects in the same texture map for production?

polycounter lvl 3
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VanessaCeline polycounter lvl 3

Hey, I am not sure where I have this from, but I think I've read somewhere that translucent textures and solid textures should have separate texture maps. Is there any truth to that? Or can they be mixed into the same texture map?

I am currently doing an art test for a AAA studio and I want to be sure that I got this right, so I can do things properly.


  • Alex_J
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    Alex_J godlike master sticky

    i think the way the shader is setup would determine how you might pack (or not pack) your maps, and that is a problem for a tech artist to solve (I'm assuming you are making some art asset here, not developing shaders?)

    In general if you can reduce total number of maps you are using, that's good, but it's probably better to keep things separated until you know what the project demands. Think about it like lego pieces. If you have a bunch of loose legos, you can build anything. If you try to guess at what should be built and put together something ahead of time, then when you actually find out what is meant to be built, now the first thing you have to do is tear it all apart to get back to loose pieces.

    If you wanted to demonstrate that you know how to pack texture channels, you might look up a few common channel packings and offer one of each. It's something only takes a few minutes to do so why not I guess. I doubt its a very important criteria though because anybody who can follow instructions can just be told how to pack the textures.

    "Doing things properly" means recognizing what you don't know and preparing a plan to get around that - it doesn't mean feigning that you know things that you don't. In making games whats more important than secret knowledge is knowing how to keep your pipeline flexible because requirements are going to keep changing all the way up until the end. So, the faster you can adapt to changes, the better.

  • pior
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    pior grand marshal polycounter

    "I've read somewhere that translucent textures and solid textures should have separate texture maps. "

    Well, the way you are phrasing this doesn't make much sense, and the terms used suggest that you are confusing things. Even the use of the word "translucent" is odd.

    Now it's totally ok to not know something - but here in this case it really is impossible to give you any practical answer since we cannot see the asset, and we are not the ones giving you the art test anyways.

    The only rule of thumb is that wastful use of ressources is to be avoided ... unless it is impossible to do so because of this or that limitation.

    Very broadly speaking, if you have a full asset/character only requiring a tiny bit of geo to have some alpha masking/transparency applied to it (like the lenses of some googles for instance), then it makes sense to have a tiny material and a tiny texture for just that because sorting the depth and transparency of a the whole thing just for a tiny bit would be wasteful. But some games may be setup in such a way that doesn't allow that. Another setup could involve two materials, all sourcing the color info from a common texture, and one of the two materials having its transparent effect achieved directly in code as opposed to sourcing a texture mask. Who knows.

    At the end of the day this is an art test anyways - not a techart test, and likely not an interview for a lead/senior 3d position, so all you have to do is to ask the studio for more details and clarifications if needed. If they are interested in your art skills they wont care about a small misunderstanding about this or that technical term. And even if someone else competing with you has some fantastic understanding of techart and shaders, it won't help them at all if their modeling and texturing suck.

    So most importantly : good luck !

  • killnpc
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    killnpc interpolator

    you can define opaque regions with an opacity shader. so yes. were an asset or part of one using multiple materials entirely opaque, using an opacity shader for it, would be wasteful. an opacity shader is more expensive and not using transparency, or using only a few pixels for it, would be considered wasteful. from a broader view, overly obsessing over efficiency can be wasteful from a production cost perspective. if the construction of the asset is so wasteful its detrimental to performance, optimization is worth the effort.

  • poopipe
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    poopipe godlike master sticky

    Yeah, you almost always want to separate them

    Alpha blended materials are far, far more expensive per pixel, do not sort properly unless made even more expensive and generally do not light the same as opaque materials (see unreal for several examples)

    You can share the same textures if your materials expect their textures packed the same way and save some memory sometimes but other times you can't and you end up duplicating textures at compile time.

    In short - separate the translucent bit, nobody will complain about that

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