Height map baking/exporting

[Nick245827678ml2]

I am having an issue baking/exporting height detail. I wish to use my high res from zbrush to bake my details and then add more detail via substance materials and such and then export the result as a hieght data for displacement in maya. Baking high res to low res yeilds correct looking normal channels but the height channel looks like trash. It almost looks as if the resolution was set to 64x64 even though the bake is set for 2048. I wasn't going to worry about it since, if I remember correctly, substance combines the normal and height channels together for the height map export but that isn't working either. The following have items have failed to remedy the issue: I have tried turning it off and on again. Tried softening normals. hardening normals. Re-exporting all meshes. Starting new files. changing bake resolution. Changing bit depth. Making new meshes. changing projecting distances. I'm running out of ideas. Am I broken, or is substance?

[Cyril Dellenbach]

Hi @Nick245827678ml2,

Interesting subject.

I know this can be disturbing, but this is how to height map is supposed to work. It is made for sub-divisions and this specific look comes from the fact that it is a baked height (not a height from the normal map). You'll find multiple threads on internet about this subject with other software.

Just try the map in you rendering software and it shouldn't have any issue. Keep me posted.

Best regards,

[Nick245827678ml2]

Hiya,

Thank you for your reply and help on this subject. I guess I'm not fully understanding the application of a height map that looks like this. I can't recall ever seeing one like it. But perhaps I'm getting old and things are done differently now? Ha! Similarly I never remember substance baking height maps that look like this. I tried to open previous versions of subsance to verify but since the migration adobe, I can't long in.  Anyway, I did more tests in attached image. I baked the height in zbrush and I got a result that I expected or what I thought would be "correct". I applied that in substance as the height mesh map and get a result that I expect. I also tried applying each set of height maps as a displacement in Maya rendered in arnold. Substance maps did not yeild results I am looking for and zbrush maps did. Seeing these images, is everything behaving as it should?

[Cyril Dellenbach]

Thanks for the pictures, it has created an interesting talk with the team. The render you got with the height map from Substance 3D Painter should be closer from the one with Zbrush. What was your workflow for exporting the map? Did you export it with 16 bit depth? Do the scale was the same between the two renders?

And don't worry, I don't think you're too old for anything, it is just a different process between software for creating the Height Map. ZBrush knows the relation between the low-poly and the high-poly geometry because it's the same mesh at different subdivision level. So I presume they have a way of encoding the right surface information in the texture.

Substance Painter has less information and uses the differences in elevation between the low-poly and the high-poly, causing this "weird" visual. Also, this is why you need to use the Substance Height map with a unsmooth sub-divided object, or the map won't work as intended.

[Nick245827678ml2]

Hiya,

The zBrush map was generated at 16bit. The substance height map was 16bit as well but I tried 32bit for fun with no apparent change in final render. The general workflow I am using or attempting to use is I have my model sculpted in zBrush to somwhere around 15million polys. Low res model used in substance with the high res details baked. Apply texture and micro detail (pores and wrinkles and such) in substance. Export height detail from substance hopefully containing baked detail from high res as well as added detail from substance. Render in Arnold with height as displacement. So first problem of course is that my height map isn't baking like I am expecting in subsance. My backup plan was to import the height bake from zbrush. The second issue I seem to have is that exported height map is not including the baked height information from substance bake or zbrush bake or from the normal map. Plan C is to try to combine both height maps from subsance and zbrush together in arnold with some sort of fancy node wizardy. 

[Pandajolokia]

Yeah, havin the same problems here with substance painter and i would love to have a solution for this substantial and essential task.

Cant get normal information into a height map in Substance with baking.

I think it works to create height information in the Height channel with substance materials etc but it does not work to transfer the height data from the normal channel into the height channel.

That would be needed to create a displacement map.

[1k0]

Here either I have the same issue. (My low poly model has 1 smoothing group)
Indeed, I'm talking about painter because I have no solution for Designer yet, In painter you can use this faceted baked height map as "displacement" and not "height" map, the model will look as if the baked map was from Zbrush.

However, outside Painter, the issue stills occurs, like in 3ds Max and Arnold (what I am using).
The core problem is the way the different softwares subdivide the models to apply the baked height map.

Can someone from Adobe could confirm the subdivision process in painter is different between the use of displacement vs height or hy there is a difference between the 2 methods?

My solution (Max+Arnold) is to avoid using the subdivision pannel in Arnold Properties modifier and only use the displacement pannel, loading my height map there. Before the Arnold Properties modifier, I put an OpenSubdiv or Turbosmooth modifier and add the subdivision levels here. No more faceted look in the final render.

Of course, my model only need 2 or 3 subdivisions, depending on your computer power and scene complexity, this workflow may not work.

[1k0]

1st picture: Faceted baked map used as "Displacement"
2nd picture: Test render in Arnold with the same baked map, using subdivisions in the Arnold Propertie modifier

[Cyril Dellenbach]

The Height map exported from Substance 3D Painter should work properly with simple subdivisions, but not with Catmull-Clark subidivisions. This is in fact why you can "see" the mesh's polygons in the bitmap.

https://polycount.com/discussion/comment/1947155/#Comment_1947155

So whatever the software is, it should work as expected as long as the mesh isn't smoothed.

Best regards,

[1k0]

Indeed, Arnold use Catmull-Clark subidivisions, this explains the issue.

[Scote801]

I also getting a faceted height map.

I try few things:
1---
My lowres is a bottle I "soften edges" the mesh then export as FBX smooth mesh/triangular
My Highres is a zBrush exported version.

2---
My lowres is a bottle I export subd1 from zBrush, the mesh then export as FBX smooth mesh/triangular (no soften edge before)
My Highres is a zBrush exported version.

I also try no smooth mesh or without triangle. I also try soften edge on the high res.

Same result. I just bake in Painter and export the result. It's not the arnold or other software issue. The map look wrong directly from Painter

[deepakamba33]

i also substance painter baking hight map very bad

[Cyril Dellenbach]

Hi @Scote801,

As mentioned upthere, this is how the Height map is supposed to be, therefore no matter what you're doing, the result will always look the same.

The faceted look directly on the bitmap is due to what it is made for. The Height map exported from Substance 3D Painter is made to work on mesh with simple subdivisions (unsmoothed), but not with Catmull-Clark subidivisions (smoothed).

Try this height map in any software with a simple subdivision, it should work properly.

Best regards,

[deepakamba33]

maya export fbx substance painter bake hight map line problem, i dont understand please can u make record send me video

[deepakamba33]

i think u don't work i m angry can u make fix hight map update thanks

[Scote801]

HI @Cyril Dellenbach 

  but if the result of the exported map from Painter bake lines of the facets then the map is not useable in any softwares.

For my example below: everything should be gray 50% except the embossed parts (should be light grey or white) but substance don't provide the propre result.

see my files (2k maps with 2k bake)

https://drive.google.com/file/d/1ROe0l1Fh8MEu5Y7p8yqqk0uNAYAYnWfe/view?usp=sharing 

[Scote801]

Oups here's the link of the various geos I test

https://drive.google.com/file/d/1JfiqqcFwTNlkmJlOMn6yK88KuI3Si4eV/view?usp=sharing

[deepakamba33]

it's line problem 😞

[Scote801]

I know. We dont need to circle the issue here to see the issues 🙂

[Scote801]

is there an update on the issue?

[Cyril Dellenbach]

Hi @Scote801,

I'm sorry to insist, but there's no current issue with the baked Height map. The faceted result is the one expected.

To have the proper result inside Maya, subdivide your mesh with a simple subdivisions (unsmoothed), and not with Catmull-Clark subidivisions (smoothed).

Regards,

[deepakamba33]

not working please can u make video send me from maya

[Scote801]

OK I will try

But get with my file and my mesh a good result? Could you share the result

Cause. just reading the map itself. If black pull the nesh and white push it and 50% grey do nothing.. then all those lines in the map should do that: the dark lines visible in the map (wireframe baked) should pull in the mesh. And my result do that.. in PAINTER.

Let's ignore Maya for now. Let's try to understand why my baked result read bad and the result in Painter read bad too.

[Cyril Dellenbach]

Substance 3D Painter always convert the Height channel into a Normal, so if you simply Drag & Drop the baked Height map in the Layer Stack, it will convert it into a Normal, therefore it won't work properly.

However, you can use a Displacement channel, plug the baked Height map in a Layer at the Displacement slot, and this will work as expected.

Regards,

[Scote801]

Thanks for explaining that. I tought the height channel was the displacement.

[Scote801]

If we test at the extreme of the push, we can see the black lines DO something on the mesh. I dont think it should do that.

Personnaly I except no black lines on my gray height map. Is there a reason why Painter does it? because zBrush dont. I also can paint manualy in Photoshop a map. Black pull and white push. That Painter bake doesn't react how we suppose to get it in my opinion.