PTex rendering grey in VRay

[insalubrious]

Im not sure if this is an issue on the Mudbox side or 3ds max/vray side. Here's the workflow:

Exported mesh from max 2012 as obj with no UVs
Painted PTex paint layer in Mudbox 2014
exported as 8 bit ptex (also exported a higher resolution version of my mesh as fbx )
applied vray_Ptex shader
Default vray render settings

the ptex renders but with no color,its just grey.
Am I missing a step somewhere?

[Morbid Angel]

the base mesh has to match the base from mudbox, not a higher resolution mesh you've exported. Its point order based, so if you subdivide it once its not going to work.

[insalubrious]

thanks for the reply i just managed to get it to work,it was mentioned somewhere about maybe changing manually the rgb channels to 0/1/2 and that did the trick it's finally working.
as for the fbx export,thats something i also read that if you export as fbx from mudbox it will also export your ptex texture for that subdivision level making that your new base mesh.
still testing but seems to be working fine,thanks again!

[sparks24]

Hi, I was hoping I could get some help here for the same problem as what was originally posted: Vray rendering ptex in grey. (Posted here so I don't repeat a new thread of the same nature)

I tried all the solutions below, but to no avail:
1) changed the RGB to 0, 1, and 2, respectively.
2) change the alpha channel to 3

still not change. I exported my obj from mudbox, and make sure that "retriangulate polygons" was not ticked. Yet, still grey output render on my model. Any help/suggestions would be greatly appreciated.

[vlado]

Would be best to get us a scene to vray@chaosgroup.com - our support guys will be able to help you out.

Best regards,
Vlado

[sparks24]

Thankyou for the quick reply Vlado. The thing is my scene is about half a gig - working with a high poly head with one Vraylight. So kinda hard to send. I can try to use lower-poly count object tests first, and if it doesnt work, then I can get back to you again (I don't know what the difference would be, but I will try).

[sparks24]

Hi Vlado, here is a pic attached using a test low poly model. I'm also sending this to the chaos group email, so it's okay if I don't get a response here.
I'm starting to see what's going on here, but don't know how to rectify it. https://dl.dropboxusercontent.com/u/...%20problem.jpg
Top right picture is mudbox painted model with Ptex (no UVs), and bottom right is Vray render using vrayptex map node connected to a diffuse node on a vraymaterial.

[Morbid Angel]

did you check include mesh data in mudbox when you exported ptex?

[sparks24]

Hi Dmitry,

I don't recall having the option to export mesh data, I just exported the OBJ. But I will check when I get home! thank you.
Also, that is one awesome showreel you have there! Top-notch work

[Morbid Angel]

this option exists in mudbox 2014 I believe.

[sparks24]

Just tried for the past hour to get it working - but no luck. thank you though. (I do have mudbox 2014, but when i go to export the desired paint layer, it just gives me the option to save as a ptex of different qualities (8 vs 16 bit, etc)).

[sparks24]

"did you check include mesh data in mudbox when you exported ptex? " Yes, this worked! Sorry I was confused - I thought there was prompt to save mesh data in mudbox upon export of the paint layer - but the option (for those who might have this problem as well) is found under windows>preferences>Files>save mesh data in PTEX files. Thanks for you help!

[Olor1973]

this option exists in mudbox 2014 I believe.