Transfer polypaint to keyshot WITHOUT material information?

Started by ghostweeble, March 18, 2015, 03:37:07 PM

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ghostweeble

Hello,

I would like to know how to transfer just the pure polypaint info from my model in ZBrush into Keyshot without the matcap material information being baked into the color texture that is created for keyshot.

Thanks!

slothkins

guest84672

You can always swap out the underlying material and keep the polypaint as a texture. Does that help?


ghostweeble

#3
Hi guys,

Sorry I didn't see your replies until today. For some reason I wasn't notified, even though I subscribed to this thread.

thomasteger:
Swapping out the material in keyshot (by ALT+dragging onto the model) doesn't work. The matcap shading seems  to be retained.

tqped:
In doing some tests you're right! Using flat material is the only way to transfer the polypaint to Keyshot without shading/specular of the matcap so that the materials can be truly changed in Keyshot.

There are some workflow issues that I'm hoping you might be able to address:

I currently use a material called ZbroPaint in zbrush to do my polypainting (it's a material that's good for painting textures as the shading is not strong). My findings are that after I have sent a model through to Keyshot, the material will not change, even if I change the material in Zbrush and resend to Keyshot. Interestingly, the polypaint does update in Keyshot correctly, so that leads me to believe that Keyshot actually does handle the polypaint and Matcap separately.

I think this may be a bug, as I can't imagine that this is the intended behavior?

What I'd like to be able to do is polypaint in ZBrush using the ZbroPaint material while doing test renders in Keyshot to preview my work. Then, when I've finished, change the material to flat color so that I can properly change the material in Keyshot.

Right now there doesn't seem to be a way to do this, which is limiting. I hope that this can be fixed or there's some workaround I'm missing?

Let me know if this makes sense, I'm happy to explain further or create example files to illustrate the issue more clearly.

Thanks!

mm




tqped

hm, it's not a bug.

you know there are 3 ways of polypainting in zbrush?
that's why there are 3 buttons in de toolbar.
mrgb: material plus color,
rgb: color only
m: only material.

i guess you are polypainting with mrgb on, thus material and rgb color.

only way to export this from polypaint to texture is with the excellent plugin from J. Drust, matcapbaker.
you can find it here http://www.zbrushcentral.com/showthread.php?170886-MatCap-Baker!-unofficial-Information-Installation.

let me know if this helps or if you need more info.
and do not mind my bad english. (i am dutch speaking)

grtz p

ghostweeble

Hi tqed,

I do understand the difference between "M" material painting, "RGB" color painting and "MRGB" material and color.

1. I don't want the materials from zbrush transferred to keyshot, only RGB information, so that I can then change the materials in zbrush and retain the pure RGB info from zbrush.

2. The flat material in zbrush is the only material that transfers the RGB information without zbrush material specular/shading/matcap information.

3. The first time a model is transferred through the keyshot bridge, the zbrush material that was transferred initially is permanent! If I subsequently change the material in zbrush (for example if i fill the model with MatCapRedClay) and resend it to keyshot, the material does not update in keyshot, even if I modify the RGB in zbrush (which does update in keyshot correctly). This is what I'm calling a 'bug' or limitation.

I think communicating the issues I have verbally is difficult for me and I'll have to put together visual reference and files.

Thanks,

mm

tqped

jep, i did some tests, and your right.
didn't know that and i do not know if this is a bug.
it certainly is a limitation.

on the other hand, why whould you change your material in zbrush while polypainting?

as long as the changes you polypaint in rgb are correctly send to keyshot to preview, everything is ok, not?
after the polypaintingjob is finished you can then bake a texture from the polypaint in zbrush, (texture>create>texture from polypaint),
export it, and use that in most of keyshot material-colorslots. (some of the keyshotmaterials don't have a slot for colortextures)



ghostweeble

EUREKA!!!!

I've found that if I turn "Group by materials" ON under external render in ZBrush, then the material updates in keyshot with no problem. I'm not sure if this is the default and I somehow turned this parameter off accidentally? It still seems like a bug to me, as this doesn't seem to make sense in what this parameter is supposed to do.

Either way I can now just switch to Flat color and transfer the model over. I would still prefer to have only the RGB info stay when swapping materials in Keyshot, but this will work.

tqped, the point is I do not always want to make a texture as many times I do not even have UV's on my models sent to keyshot. This is for concept illustrations and also just for quick workflow (Which is the whole point of using Keyshot vs. exporting to another 3d app). My goal is to transfer JUST the RGB polypaint to keyshot, so that I can then switch the material in keyshot and not have the matcap shading included. Using flat color does this and now with "Group by materials" on so that I can update the material in keyshot, this will work.

Thanks,

mm

tqped

nice find.
testing it now.

glad i could help (a little)

grtz p

bobKotlinski


soren

If I understand the ZBrush terms correctly, the poly-paint information is transferred using vertex color into KeyShot.

After you have imported your model, change the texture type to Vertex Color and you should have the RGB paint only. You can use the vertex color texture like any other in the material graph for full flexibility (i.e. use with labels etc etc). You may want to apply a color adjust node in the material graph to adjust the contrast.

Søren

ghostweeble

#11
Hi Søren,

I just saw your reply now. I thought I was subscribed to this thread but I guess not!

I'd never seen that vertex color mode under the texture, thanks for pointing it out. It's still not working as I'd expect and I'm confused at how Keyshot is actually translating the colorspace from Zbrush into Keyshot.  I still cannot get pure RGB vertex color info transferred into Keyshot via the bridge. (See my attached image that shows the issue.)

Please let me know if you have any questions I could clarify.

EDIT: I wonder if I should post this as a new thread?

Thanks!


soren

I do not know exactly how ZBrush transfers material information to KeyShot- we simply render it.

MatCap's are not physically based materials so when using them in KeyShot you will at times get peculiar results.

As I wrote above, I do not know how ZBrush converts their data to our format, but I a wild guess would be to add a color adjust node between the diffuse channel and the vertex color node and set the color adjust node contrast to 2 (see attached).

If you have any further issues, I suggest you contact ZBrush support.

Søren

ghostweeble

Thank you,

I'll try to inquire with Pixologic support. There really shouldn't be a need for wild guesses I would imagine?


soren

Did you try the color adjust node as I described? To reproduce the effect of the texture map, you will have to add that node.

Søren