Hide texture repetition - what's the state of art solution?

bitinn

Say I have following:

- a set of fairly low poly modular wall models.
- a few tileable textures: wall, broken walls, etc.
- I want to blend these textures to hide the repeat tiling when you have a long stretch of walls.

Now, I know there are 2 general approaches:

- vertex color blending: this is no go for me due to model being too low poly.
- texture blending: this is possible but ...

I need at least 2 UV here, right? One for tiling textures and Another for the blending/splat texture?

- I know 3A games have tricks like projecting a large paintable splat texture onto the world geometry, which avoids 2nd UV.
- But doing this for all walls seem difficult, not to mention it will be a custom solution that only works in game engine.
- It also doesn't work in a more dynamic world, as the splat texture is authored, not generated.

So I am weighting my options here:

- I could go with 2 UV, and create variation by having more splat texture, the upside is this can be done in common DCC, the downside is, of course, more work.
- I could go with a procedural solution, where we blend textures differently based on world position and some noise, the upside is even user-created content would be fine, the downside is they are less interesting than authored ones.

Are there any other solution I am not aware of?

Obscura

Yeah there is one more. Its called "texture bombing" or "stochastic texturing". What this does is to apply some offsets and rotations, maybe even scales on the uv tiles. Keep in mind that this is still repeating the texture, but in a much less obvious way. Its also much more expensive than traditional tiling.
https://www.google.com/search?q=texture+bombing&rlz=1C1GCEU_enHU838HU838&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjuvquyya3lAhWjlYsKHWCBAY8Q_AUIEigB&biw=1920&bih=1009

bitinn

Obscura said:

Yeah there is one more. Its called "texture bombing" or "stochastic texturing". What this does is to apply some offsets and rotations, maybe even scales on the uv tiles. Keep in mind that this is still repeating the texture, but in a much less obvious way. Its also much more expensive than traditional tiling.
https://www.google.com/search?q=texture+bombing&rlz=1C1GCEU_enHU838HU838&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjuvquyya3lAhWjlYsKHWCBAY8Q_AUIEigB&biw=1920&bih=1009

Thx. Texture bombing is an interesting idea, the limitation appears to be the random feature must be small (dirt and small decals are probably fine).

As for stochastic texturing, yeah there are new solutions, but they usually don't work with regular pattern texture like brick walls.

Obscura

Thats right, this doesn't work with recognizable patterns, such as bricks or tiles.

Eric Chadwick

You could perhaps use a single uv set, but just tile the mask less than the main wall texture. There's some older info on the UDK wiki about this, for terrains but could be adapted for any mesh. 

oglu

I would go for unique textured wall elements. No tiling textures at all.
This depends on the project and on the platform you have to work.

bitinn

Eric Chadwick said:

You could perhaps use a single uv set, but just tile the mask less than the main wall texture. There's some older info on the UDK wiki about this, for terrains but could be adapted for any mesh. 

This is an interesting idea, a side question if you don't mind:

When making a multi-texture material (one that blends multiple set of diffuse/normal/RMA), it is standard practice to pack the decal(s) as individual channels in a separate texture, right? Because you need to sample it using a different UV offset and scaling, unlike other tiling textures.

I have seen The Division 2 team mention this in their Substance talk, where they call it grunge breaker (to hide obvious tiling produced by decal grunges).

bitinn

oglu said:

I would go for unique textured wall elements. No tiling textures at all.
This depends on the project and on the platform you have to work.

I would do this if I am building The Sims , but blending make our work more reusable in this case as we don't have to build 5 specific variants from 2 textures, and can procedurally do this for player-created content (The Sims basically ask the player to do the artist's work, and some players enjoy it, haha)

Eric Chadwick

bitinn said:

When making a multi-texture material (one that blends multiple set of diffuse/normal/RMA), it is standard practice to pack the decal(s) as individual channels in a separate texture, right? Because you need to sample it using a different UV offset and scaling, unlike other tiling textures.

I have seen The Division 2 team mention this in their Substance talk, where they call it grunge breaker (to hide obvious tiling produced by decal grunges).

Those are two separate things, multitexture vs decsls. Neither is dependent on the other. There is no standard practice, it all depends.

Channel-packing decals makes sense sometimes, but only if you want to apply a single color for each one. Channels are each grayscale. 

WitchDev

Hello, I just registered here because I have created a material in unreal to hide texture repetition some time ago and shared it on the unreal forum(along with a sample project on GitHub). It's inspired by the stochastic texturing idea but uses a heightmap instead to create the final output. It triples the number of texture fetches and adds some math, but hides repetition really well.

https://forums.unrealengine.com/community/community-content-tools-and-tutorials/1603512-randomized-tiling-function-eliminate-repeating-patterns-in-your-textures

Obscura said:

Thats right, this doesn't work with recognizable patterns, such as bricks or tiles.

I haven't really tried much to use it with textures with bricks or tiles, but in theory if you don't scale the textures and don't rotate them (or at only like 90 degree intervals) it might work reasonably well if the random offsets get limited to fixed intervals (like only 1/8th of a texture steps if the texture is 8 bricks high)

V!nc3r

bitinn said:

I have seen The Division 2 team mention this in their Substance talk

Is it this one? The Division 2: A World of Materials @GDC 2019

bitinn

V!nc3r said:

bitinn said:

I have seen The Division 2 team mention this in their Substance talk

Is it this one? The Division 2: A World of Materials @GDC 2019

Correct

poopipe

There's Wang tiling - that's fun

There's probably plenty that can be done in terms of randomly selecting maps from a texture array and tiling them

jStins

poopipe said:

There's Wang tiling - that's fun

I'm incredibly apprehensive about googling that term.

poopipe

Do it at work....

https://en.wikipedia.org/wiki/Wang_tile

Eric Chadwick

search "Do it at work" at work

Mark Dygert

I don't have that much time to read the whole thread so i apologize if it came up already, but decals and mesh decals they can really help add detail and break up tiling patterns.

Unreal's mesh decals can be used to break up tiling and add detail. They aren't just for blood splatters and puddles...
https://docs.unrealengine.com/en-US/Engine/Rendering/Materials/MeshDecals/index.html

Also the newly added Material Layering System is still experimental, but fan-f*ckin-tastic.
https://docs.unrealengine.com/en-US/Engine/Rendering/Materials/MaterialLayers/index.html

These concepts can be applied to other engines in other ways too.