Working with tiling mats in UE4.

Count Vader

I'm thinking of adopting a tiling texture workflow for the environment I am currently working on. I've been seeing some amazing art using this technique, and hey, who the hell likes baking anyway. Now that it's reasonable to have meshes with a high enough density to support chamfered edges, I see no reason to ever bake env. stuff again. Of course the drawback is you don't really get the nice localization of dirt/scratches that you would with unique UV's, but Alien Isolation (and some of the art coming out of Star Citizen that I've seen) looks absolutely insane, and they don't seem worried about that drawback, so whatever.

So my question is - if I am using a tiling texture workflow, should I still unwrap stuff, or just throw a UVW map modifier on it in max set to Box projection, and bring it into UE that way? Or will it freak out on me for some reason.

Obscura

Hello, I think you would find my thread helpful, it is highly connected to what you are asking and saying. Here it is:
http://www.polycount.com/forum/showthread.php?t=154664

There are ways to add unique details anyways. This is where decals can become really powerful. For the UV question, I would say it depends. There is a way to work with no UV at all if the materials are tiling. Also, when you want to change material after an edge (red wall goes to blue, or wanting to add in a detail, etc) unwrapping can be useful. On the 4th page of my thread, I'm trying to completely recreate the star citizen technique, so its a chamfered mesh with edited normals, only tiling materials, and decals on top of that. My shaders built to not need an UVmap for the tiling surfaces, because I'm projecting them from 3 directions (still very flexible, and can work with moving objects). I would say you can get the same quality with these techniques as with baking, if not better, because you CAN get much better resolution with the mixed workflows.

Count Vader

Obscura wrote: »

Hello, I think you would find my thread helpful, it is highly connected to what you are asking and saying. Here it is:
http://www.polycount.com/forum/showthread.php?t=154664

There are ways to add unique details anyways. This is where decals can become really powerful. For the UV question, I would say it depends. There is a way to work with no UV at all if the materials are tiling. Also, when you want to change material after an edge (red wall goes to blue, or wanting to add in a detail, etc) unwrapping can be useful. On the 4th page of my thread, I'm trying to completely recreate the star citizen technique, so its a chamfered mesh with edited normals, only tiling materials, and decals on top of that. My shaders built to not need an UVmap for the tiling surfaces, because I'm projecting them from 3 directions (still very flexible, and can work with moving objects). I would say you can get the same quality with these techniques as with baking, if not better, because you CAN get much better resolution with the mixed workflows.

AH yes!! I actually came upon that thread as soon as I got the inevitable issue of shading artifacts from putting everything in 1 smoothing group, your explanation of vertex normals was immensely helpful, so thank you so much for that!

Also, yeah I can see what you mean about paint stripes or things like that, I guess the way I thought about getting around that was to have an edge loop wherever there's changes like that, and just give that part a separate mat ID, though that would of course not work so well if the change in color is in an irregular shape or doesn't correspond to the flow of the mesh.

You had an example where you added in normals in Ndo -- was that multiple material channels or did you just do unique UV's but just with chambered edges?

Obscura

For this door, I used unique textures+supportloops on the edges. But it is completely doable with tiling mats+decals too.

You are right, generally you need extra edges+material IDs. Plus the decals if they are needed. They are more powerful than you'd think.

Obscura

Here is the Star Citizen art dump thread, where you can see some of the technical details of that ship. He mostly used tiling mats+decals. Even every single bolt,screw, button, text, etc was a decal.

http://www.polycount.com/forum/showthread.php?t=154261


Feel free to ask if you need more info.

Count Vader

Ah! Didn't know there was a star citizen art dump thread, that's awesome.

So as far as decals for things like screws or something go, I guess you would place them onto a plane and then copy-stamp that plane around your geo? So essentially floating geometry but it's all just planes with the decal on them? Sort of how the screw heads were done on this monitor from A:I ?

Der Hollander

For smaller props, you could also try what Tor Frick did, using an atlas texture for details. There's a little more work involved getting the UVs to work on each asset, but you could totally use it with custom vertex normals to avoid baking down assets.

Obscura

Possibly...Luckily I could collect the given artists in my thread, so you can ask there. I might start a specific thread though as we are digging deeper. Actually it is getting closer and closer to what #Der Hollander is mentioning. Your image is kinda confusing btw, I couldn't properly determine whats happening with that computer. As I see there's a hax with alpha but theres definitely a haxery with vertex normals...But as I see there must be an advanced use of decals though! As I mentioned earlier, they are more powerful than you'd though. This is how you can add custom or unique details. Also there are other ways too... As Matthew saying there is a way to use vertex blending for edge wear or such. Still, if you have any specific question regarding the workflow, except what I told already, you can ask. And still, probably I will start a specific thread soon!

In a short answer, yeah, they are floating geo, and they work fine, if the shader allows it to work well.

Obscura

These mixed workflows give you many possibilities! Unfortunately they require a lot more understanding in technical art.

Obscura

For the decals:
Actually there was no way for recreating the star citizen method with the default possibilities in UE, BUT if you can understand the logic, there are no limits. Nodes give you mid range freedom, and if you can utilize this well, you can pretty much reverse engineer them, as I did. My method works in UE. I'd say stay tuned, I'll come up with an advanced explanation really soon. I just need to find the golden balance...There are alway pros and cons... If you are interested in my personal opinion, then I'd say these methods are completely OK on a PC, even on a medium one, they are working completely fine on my one, which is outdated. Also, DX 12 is really close As a closing here, I'd say you can definitely see the potential of the decals even in your example. Still, an advanced usage requires understanding in technical art if you have no pre built tools.

Count Vader

@ Der Hollander Yeah, I definitely plan to adopt a similar approach to the project after this one, since it features more fine but potentially repeatable tech details than the one I'm working on now.


@ Obscura Just to be clear, decals means a flat texture w/alpha. that I can stick on top of geo-in game (ie if I want leaks on a wall or a something). Or is there a lot more to it than that?

Obscura

Well, these decals are a bit more complex, but basically they are a texture with alpha. Sometimes they doesn't require alpha. But everything depends on how the material set up.

Count Vader

Alright, well let me know if you do end up making a thread about this stuff, I'd love to know more about the advanced aspect of using decals.

Count Vader

Also, I wanna address lightmaps for a minute. Still do them with this workflow, or go all dynamic? Because of the greater detail in the geometry I imagine the lightmaps would need to be pretty damn massive to get a decent look. But going all dynamic (in unreal at least) means no lightmass/scattered lighting/proper shadows? Is that a reasonable assessment of the tradeoff involved?

Obscura

Lightmaps doesn't have much to do with the technique, but you are right, with the more modeled details, you would probably need bigger lightmaps. There are already 2 ways for dynamic global illumination in ue4 btw :P Dynamic lighting can be expensive, so I'd say use it only if you really need it, in a case like a day night cycle or when lightmaps wouldn't work. That day night cycle would be the least expensive case of dynamic lighting, because you only need one dynamic light. It goes more expensive, when you have more than one, and they would cast dynamic shadows, especially if they are intersecting each other's attenuation. For people who want dynamic lighting, I would suggest to use it in an optimized way, or to use CE instead. But even there, you probably can't make every single light dynamic shadow casting.

Count Vader

Ah, cool. The reason I was asking about lightmaps is I was hoping to get away from unwrapping altogether with this workflow, but it sounds like I still have to unwrap for lightmaps.