Weird artifacts on baking textures from high to low poly

parikshittiwari

Hii guys,
I am extremely new to the world of 3D and Substance Painter. I am trying to model and texture a game asset from Maya and Substance Painter. The problem I am facing is whenever I try to bake the high poly on my low poly model in Substance, I am getting weird results all over it and can't pinpoint what exactly I am doing wrong. 

I have followed the general advice of:
1. Adding suffix on both high and low poly and changing that setting in Substance to match with suffix.
2. Softening the edges on the low and the high poly.

I have uploaded all relevant screenshots and also the link for my fbx files for both of my high and low poly model. 
Link: https://drive.google.com/drive/folders/1uR_gloedjVsDTF0sPq1p6l0hWGbRsWdu?usp=sharing

Benjammin

First two pics: your low poly cylindrical elements need more divisions to better match the high poly -You're not doing anything 'wrong' here necessarily; Its a judgement call on how good it looks at the expected view distance in-game.

Last pic has the same issue, but the weirdness happening in the cut outs is because those edges should be hard, or bevelled - normal maps don't like that kind of extreme angle change. 

You shouldn't be softening ALL edges, especially on small details. 

Kanni3d

additionally, almost nothing in your uv sheet is perfectly straight. Anything that's on a slight angle/not pixel straight will have tons of stepping/aliasing in your bakes and textures.

parikshittiwari

Benjammin said:

First two pics: your low poly cylindrical elements need more divisions to better match the high poly -You're not doing anything 'wrong' here necessarily; Its a judgement call on how good it looks at the expected view distance in-game.

Last pic has the same issue, but the weirdness happening in the cut outs is because those edges should be hard, or bevelled - normal maps don't like that kind of extreme angle change. 

You shouldn't be softening ALL edges, especially on small details. 

Hii, Really appreciate the reply as I was struggling with this problem with no solution in sight and tried many forums but nobody really replied. 

I had a couple of questions regarding what you said. I have seen many people online who sculpt a lot of details like edge wear, edge bevel and other stuff in Zbrush and bake it all on a very low poly model. I have seen it more with people who sculpt complex characters and re-topologize it to a very few polygons and bake all the details perfectly.

This confuses me a lot over what exactly are the limitations of baking a normal map or any other map because on one side I see people struggling to put details on models (someone like me) and on the other I see people baking so much that it just looks like a primitive if you remove the texture. how exactly does it work then?

Regarding the view distance, I am not making it to import in a game but rather to add to my portfolio as a beginner or you can say as a practice to understand the process of game asset creation. I would therefore like it to look as perfect as possible with as few polygons as possible so that I can demonstrate my skills accordingly. As such, could you please advice that in general where can I cut corners in terms of my poly count and where should I keep higher polycount? or maybe point out something as a reference or some tutorial?

parikshittiwari

Kanni3d said:

additionally, almost nothing in your uv sheet is perfectly straight. Anything that's on a slight angle/not pixel straight will have tons of stepping/aliasing in your bakes and textures.

Hii, Really appreciate you helping me out.

By perfectly straight, do you mean to say that I should orient them perfectly straight or the UV islands itself should all be straight and not make an arc like they are doing in my particular model?

Because many of them if I try to straighten out start producing stretches and distortion. In such a scenario, what do you recommend? Should I cut them more to a point where I can get them to straighten out without distortion? 

Kanni3d

Because many of them if I try to straighten out start producing stretches and distortion. In such a scenario, what do you recommend?

Minor distortion is sometimes unavoidable, but the benefits outweigh the cons. If you need to cut/split off some areas to easily achieve that, or to reduce a lot of distortion, then sure.

But yes, a lot of the UV's you have that are naturally straight/box shaped are slightly on an angle. They should be perfectly flat so pixels can "snap" to them, rather than have chunkiness and stepping issues.

Benjammin

parikshittiwari said:

This confuses me a lot over what exactly are the limitations of baking a normal map or any other map because on one side I see people struggling to put details on models (someone like me) and on the other I see people baking so much that it just looks like a primitive if you remove the texture. how exactly does it work then?

Regarding the view distance, I am not making it to import in a game but rather to add to my portfolio as a beginner or you can say as a practice to understand the process of game asset creation. I would therefore like it to look as perfect as possible with as few polygons as possible so that I can demonstrate my skills accordingly. As such, could you please advice that in general where can I cut corners in terms of my poly count and where should I keep higher polycount? or maybe point out something as a reference or some tutorial?

There are huge threads on polycount explaining all of the technical details better than I could (https://polycount.com/discussion/163872/long-running-technical-talk-threads#latest). 

In terms of poly count, its up to you with portfolio work, because the guidelines you would use in game dev (importance, scale, view distance) are out the window. These days, the number matters far less than how they're fed to the renderer, so my advice would be to raise it up so those cylindrical elements bake correctly, and add some bevels. Experiment with how more geo affects the bake, and the difference between bevelling and hard edges. There's really no shortcut to learning this stuff IMO - you just kinda have to get in there, mess up, troubleshoot and try things out. 

gnoop

I would just bake some "rounding corners" shader  over hard /split edges  . in Arnold or Blender Cycles , Octane, Modo or whatever.     They would give you a perfect base to paint normal details further.    It would does look different on cylinders   looking more straight    without those dark corners  but IMO it's a better look probably until it's super few geo.

No ray distance headache   or cages

parikshittiwari

Kanni3d said:

Because many of them if I try to straighten out start producing stretches and distortion. In such a scenario, what do you recommend?

Minor distortion is sometimes unavoidable, but the benefits outweigh the cons. If you need to cut/split off some areas to easily achieve that, or to reduce a lot of distortion, then sure.

But yes, a lot of the UV's you have that are naturally straight/box shaped are slightly on an angle. They should be perfectly flat so pixels can "snap" to them, rather than have chunkiness and stepping issues.

Ok. I will try aligning them more perfectly and also try to straighten the others as much as I can. Thanks

parikshittiwari

gnoop said:

I would just bake some "rounding corners" shader  over hard /split edges  . in Arnold or Blender Cycles , Octane, Modo or whatever.     They would give you a perfect base to paint normal details further.    It would does look different on cylinders   looking more straight    without those dark corners  but IMO it's a better look probably until it's super few geo.

No ray distance headache   or cages

While this is a very good suggestion, I specifically made this model to understand the whole workflow of game asset creation and how baking works. I am just a student and this will go to my portfolio but this seems like a very interesting thing to do and I will try this too. Will get back to you once I try this.

parikshittiwari

Benjammin said:

parikshittiwari said:

This confuses me a lot over what exactly are the limitations of baking a normal map or any other map because on one side I see people struggling to put details on models (someone like me) and on the other I see people baking so much that it just looks like a primitive if you remove the texture. how exactly does it work then?

Regarding the view distance, I am not making it to import in a game but rather to add to my portfolio as a beginner or you can say as a practice to understand the process of game asset creation. I would therefore like it to look as perfect as possible with as few polygons as possible so that I can demonstrate my skills accordingly. As such, could you please advice that in general where can I cut corners in terms of my poly count and where should I keep higher polycount? or maybe point out something as a reference or some tutorial?

There are huge threads on polycount explaining all of the technical details better than I could (https://polycount.com/discussion/163872/long-running-technical-talk-threads#latest). 

In terms of poly count, its up to you with portfolio work, because the guidelines you would use in game dev (importance, scale, view distance) are out the window. These days, the number matters far less than how they're fed to the renderer, so my advice would be to raise it up so those cylindrical elements bake correctly, and add some bevels. Experiment with how more geo affects the bake, and the difference between bevelling and hard edges. There's really no shortcut to learning this stuff IMO - you just kinda have to get in there, mess up, troubleshoot and try things out. 

I guess experimenting and troubleshooting is my best bet here. I think I will take some time to understand how different geometry types work in baking and then try to model something by applying my new-found knowledge.

Thanks for pointing me to the right thread and I gotta say, I should have discovered this goldmine early on. These threads are definitely one of the most in-depth and informative out there.