Beveled Assets and Tiling Textures. Techniques?

VanessaCeline

• Hey, what would be the approach in using beveled assets with tiling textures?

• How can you get those assets to look more realistic since they use more "flat" textures without any specific area dirt, etc. I know decals and vertex painting are a thing, but aren't they expensive for performance?
• If I have tiling textures, what would be the best way to get ornaments into the asset? Are decals also the answer here, or is there something better? 

icegodofhungary

If you're referring to something like the Star Citizen technique, it's a trade off. You use tiling textures with face-weighted normals and in turn you save time by not having unique UVs and you don't have as much texture memory used. In term of ornamentation, you just model them like anything else. Anything small like screws or panel lines, you would use deferred decals. So any extra strain from height blending or vertex coloring is balanced out by saving time and using fewer textures overall.

VanessaCeline

@icegodofhungary I've read somewhere that decals are really performance expensive though. If everything is tiling textures then you probably have to use a lot of decals and vertex painting, right? 

Benjammin

Everything has a performance cost. Rather than worry about the performance cost of X, its more important to weigh the cost of X vs. Y, multiplied by time. 

VanessaCeline

Yes... after looking through forums I started realizing that it's mostly a matter of choice and also depends on what you are doing. I would still like to know more specifics or alteratives, like common practices people use and so on.

For decals for example, in a smaller environment, how many would be accepted and how it the cost of those calculated in the game engine? Since a decal could be for example a 2polygon plane with a alpha and a texture, does the engine calculate the additional texture plus transparency calculations plus polygons or is there something else to it as well? Trying to understand this in order to know how much i'd be able to use them. 

I want to start using tiling textures more and adding variation afterwards. But if tiling textures are used to save performance and time, then does the concept of creating a lot of decals go against that, because you'd need time for those and they would again, take some performance.

Just trying to wrap my head around it. 

icegodofhungary

I think you're pretty safe. In the original SC technique megathread, people were using dozens of decals that were more than just alpha and color. They included normals, and roughness in some cases. I don't think it's something you would use too much even if you tried. In Deus Ex: Mankind Divided, the prison environment used in one of the expansions is almost all decals. Dozens of decals per object, and quite a few objects per scene. Again, I don't think you have to worry about it too much. It's good to try to work within a realistic framework, but your AD would give you any technical limitations for a project. It depends per project and scene/level. Someone would be there to guide you through those kinds of things, they wouldn't make you guess at it.

VanessaCeline

Trying to get this information for a personal / university project, so sadly there's no one to guide me here haha. Yes it's an university project with no guidance. )

Anyway, I'm really happy to know that I can use a lot of them! 

Also, I probably can add multiple decals in one texture map right? And just position the UVs in the right place? I think I saw some people doing that at some point :-? 

Eric Chadwick

Yes, you can! Some examples here, along with links to their threads. http://wiki.polycount.com/wiki/ChannelPacking

icegodofhungary

Here are some good resources for the technique that I have found

Long thread but worth the read and pictures - https://polycount.com/discussion/155894/decal-technique-from-star-citizen/p1

Specifically talks about performance costs - https://polycount.com/discussion/214712/trying-to-understand-star-citizen-workflow-optimization-for-ue4

Walk-through of a scene - https://polycount.com/discussion/183764/ue4-wip-star-citizen-corridor-environment

Millennia did a video tut on it - https://www.youtube.com/watch?v=66IGMnPgEW0

Kristof's video of it that was linked in that big thread - https://www.youtube.com/watch?v=3_MG9yMbh-Y

Here's a long video on using deferred decals with blender/unreal, the general concept is the same if you're using maya or Max though - https://www.youtube.com/watch?v=tvo5QcMs4uc

Here is one of the people who actually worked on SC, the wireframe pictures of his SC work will show you how many decals used, it's quite a bit in a small area - https://www.artstation.com/trevelyan

VanessaCeline

Thank you both so so much for the resources! I will make sure to go through all of them, can't wait to get some knowledge haha

MisterSande

sadly UE4 is not stable using deferred decals and so far I do not think there will be improvements coming anytime soon. I did manage to sucesfully use normal/roughness/metal decals which is great but its just a step-up to deferred decals method which could be a game changer if combined with the weighted normals workflow.