Best method to overlay bakes?

kmahon99

Hopefully this is a simple one, I've got an asset for use in a game and I need to add the model bake onto a texture. I've done this before but it used to just be me setting the bake to multiply and layering it on.

However I've been told that the proper way to add a bake to a texture is to layer on a multiply layer at 50% opacity and a copy on top with an overlay filter set to 70% opacity. I gave this a go but the texture seems to lose most of it's color and become 'washed' looking.

I want this bake to give a proper impression of the asset being lit (it's an indoor space) by natural light, my bake was done in a Mental Ray sky portal lighting environment for Max and overall I'd say the bake looks convincing (but that may just be inexperience). However just setting it to multiply over the texture sort of removes the brightness of the light entering the space.

So could anyone give me an idea if the 50%:70% ratio I was told about is the best method, or should I be doing it differently?

Thanks!

[HP]

If you have ndo2 you can go to Mix -> Overlay Normal.

If not, you can set it to Overlay, attach a levels and set it as this

kmahon99

Ah sorry, I should clarify: This bake is actually a shadow map, I want to layer it on top of the base texture to hard-bake shading on the asset. The issue I'm having is that I can't layer on the bake (which has been rendered in Max with the aim of shading the asset so that the scene appears to be realistically lit when I put the bake on the texture) in such a way that the bake makes the texture appear more realistically lit.

I can layer the bake on but in the game the areas closer to the windows don't seem to be much brighter than the rest of the asset. Overall everything looks rather dull and I'm wondering if I'm applying the bake incorrectly? I can show what the issue is if that would help people, however the project isn't a public one so I'd rather not post images of it unless it's needed.

Thanks again.

[HP]

Oh I see, I've tried using Overlay for my AO's but never really get a result I can trust to be decent, if the pixels in the Overlay layer are less than 128, input gets darkened, if they're greater than 128, it gets brighter; so you wanna be in the middle, where the pixels are 128 . it becomes really weird and hard to tweak so I still rely on the good old Multiply method.

Basicaly, if you overlay white on an image, it gets washed out, kinda tricky.


You'd also need to give more context on what you're building and which engine, because if you're using a PBR engine, AO maps need to be it's own map and imput into the shader that way, the engine does all the overlaying for you.

kmahon99

Well it's an interior scene, a train cab to be specific. I've done a render of the lighting setup in Max and posted it below:

I asked about proper baking practices in Max a few days ago but never got a reply, so I dropped the scanline renderer and went for the MR method. I don't know if this is considered a good/decent lighting setup as I don't have much experience to say so. But to me the areas around the windows are nicely lit and it gives the cab itself a somewhat realistic look. However in-game (game is Train Sim 2014) the bake provides little to no influence on the amount of simulated light in the cab. Everything looks dull and I'm starting to wonder if it's the shaders I set it up with that are giving me hassle?

Here's how it looks in the game, to me it looks far more dull than it looked in Max. I know I added textures under the bake, but the underlying colors are very bright themselves. I know most won't know the TS2014 game engine, but maybe someone can give me an idea as to how I can achieve a better result?

I'm benchmarking this off a friend's product, which has a very convincing light bake in the cab. I just want to make this one look more natural on bright days...

Quack!

The shadows look fine to me. Even a little bit strong for a full sunlit room with all of those windows.

cryrid

However I've been told that the proper way to add a bake to a texture is to layer on a multiply layer at 50% opacity and a copy on top with an overlay filter set to 70% opacity.

If this is about baking light information into a texture, then there is no proper blending mode or ratio. Try something and if it looks off, adjust the values and try to push the result towards something you think looks better.

throttlekitty

I don't know the engine, or what's expected in the shader. Typically one would avoid directional shadowing for things that move - they'll look funky when scene lighting is coming from a different direction. This is why we typically bake out Ambient Occlusion, it gives a sense of shadowing from indirect light bounce that works under a broader set of lighting schemes.

So, how does your light map look in terms of black/white balance? I can't tell from your max render if we're viewing the map on a somewhat gray material. Anything that isn't shaded should be white, and full shadow should be close to black. You can always use Curves/Levels to boost the effect, and opacity to drop it back.

I agree with Quack!, it looks fine, but what's missing is any sense of highlight or tonal variation for each element.

kmahon99

Thanks for the opinions guys, I guess I was probably just being a bit over-sensitive to the issue. In terms of what the engine can do, it's pretty much all-round useless. Everything's environment mapped for reflections, specular isn't independent of reflectivity either etc. So I don't rely much on the game shaders to add visual quality to the assets I make.

throttlekitty wrote: »

I agree with Quack!, it looks fine, but what's missing is any sense of highlight or tonal variation for each element.

Thanks for the suggestion, but I'm not sure what you mean by highlights and tonal variation for each element? Could you elaborate? The unwarpping/texturing is still WIP by the way, so I've only got some basic paint down on some parts of the scene so far. I'll be weathering and detailing other parts once I get the proper source images for them.

It's great to get some opinions and tips from people in the industry, I don't get to talk much about my work with others so this is a great opportunity, thanks for all the help folks!:)

throttlekitty

I missed this last time, that a majority of the cabin is more or less in shadow, or at least out of direct light. The white phone has some nice contrast, but the black phone nearby is a solid color, as are most controls in the front panel. I see some highlights from lighting, but it's very subtle compared to the shadow, so colors are only going towards dark. It's hard to tell the difference between the plastic buttons and the blue paneling, in terms of "what material is this?"

edit: I have trouble putting thoughts into words sometimes, I don't think I explain well.

Quack!

Also, most of these shadow calculations are done in engine. Either via static rendered lightmaps or some fancy realtime GI system. I doubt TS has this, so baking in shadows may be prudent. I would expect it to have normal maps and specular highlights which is what throttle is trying to get at. Your materials are just diffuse at the moment and need spec/normals to sell them as more then flat color.

kmahon99

throttlekitty wrote: »

I missed this last time, that a majority of the cabin is more or less in shadow, or at least out of direct light. The white phone has some nice contrast, but the black phone nearby is a solid color, as are most controls in the front panel. I see some highlights from lighting, but it's very subtle compared to the shadow, so colors are only going towards dark. It's hard to tell the difference between the plastic buttons and the blue paneling, in terms of "what material is this?"

edit: I have trouble putting thoughts into words sometimes, I don't think I explain well.

Ah sorry I think I need to clarify, the model is still WIP, that grey phone is just a diffuse placeholder, it hasn't been unwrapped yet. Same with the paneling on the right hand side, only it's been unwrapped and just has a basic color applied to the texture.

The issue is that a spec map and a normal map exist for pretty much every texture seen here. The spec is something I find hard to work with as the engine uses the same map to control specular and reflectivity, which causes all sorts of problems when I try to make the plastic walls/panels a low reflecting but soft and strong specular material. I'd like it to be more diffuse looking, but working with this game engine rarely produces nice results. So I think I should get on to someone who works with the engine, there's no point in me asking about the details here.

I've realized how hard it is to explain art and CG in the context of a forum, so I appreciate people making the effort to say what looks off in the most concise manner possible, advice has been taken in