Vray and Zbrush

[Steve_Green]

Hi,

I've recently upgraded to Zbrush 2 which outputs displacement maps from hi-poly geometry - however when I use them with Vray I get banding on subtle areas, as if the map is 8bit even though it is a 16bit TIF.

I'm not sure whether this a Vray or Zbrush problem (Zeddicus has the same problem).

Has anyone here had success with Vray and Zbrush 2?

Thanks,

Steve

[tom schuelke]

Hi Steve

Sory i have no idea to solve your problem. But a Question. I´ve seen some z-brush videos, with very impressing stuff. We are thinking of bying this package for finetuning our modelling and renderpipline. What is your opinnion of it. Our main application is max and Vray. Is it worth it, and

what is the workflow like. Could you tell a bit of your experiance especialy about the learning curve ?

that would be very gentle.

Thanks

Tom

www.lichtecht.de /com

[J_Bug]

I've just started learning Z-Brush but I have to say that they have some of the most forward thinking methods of cutting that learning curve down quite a bit. You should definitely download the demo and see for yourself. It will only take a few minutes to realize how easy it's going to be to learn almost anything about it.

--Jon

[tom schuelke]

Thanks for your comment J_Bug

ive just been on their website for this, and i also found a PDF with grate learning and tutorial stuff. a PDF that you can download after login.

seems to be a very intristing Program for finetuning your models. We will see .

Tom

[J_Bug]

All of the PDFs are nice too but the app has it's own learning system that takes you step by step. I should have mentioned this earlier

--Jon

[Steve_Green]

Hi,

it's a very solid application, there are pdfs as well as Zscripts to take you through things.

Workflow is basically this.

Model in Max (or zspheres in Zbrush) as a low/medium detail model.

UV map if you prefer, or use Zbrushes internal mapping (though the maps are hard to edit in an external app if you do this)

Subdivide the mesh, start sculpting, subdivide etc.

At the highest level you can work with a 2D painting system (projection mapping) which is then applied to the 3D model (you can use custom brushes in this mode)

Generate displacement and/or normal maps.

Export your original low poly model if it's been UVMapped in Zbrush.

Import into Max and add a VrayDisp Modifier and the 16bit Tiff displacement map.

It can be a little unusual compared to standard window apps, but it's definitely worth persevering with.

- Steve

[J_Bug]

Hi Steve,
Have you tried converting your map to a BMP or TGA? When you say 16bit are you talking per channel or in total (millions of colorsa)? I'm not far enough along to test what your describing but if you're talking about millions of colors then you could try 24bit (true color).
--Jon

[Steve_Green]

Hi,

it's 16bits per channel for grayscale displacement maps, and 8bits per channel for normal maps.

Cheers,

Steve

[losbellos]

there is a workflow written in the "practival manual" if u havn't seen yet, check it out. Step by step instrucyions are there.

[samuel_bubat]

hi there,

i´ve written a post about that displacement "problem"sometime ago

http://www.chaoticdimension.com/foru...102&highlight=

maybe this will help you a bit
cheers

[Zeddicus]

Interesting idea about using an HDR map instead of an LDR one. Might be worth a try I suppose. I still think it might be something Zbrush is doing to the physical mesh itself everytime you press the divide button and is just getting translated into the map it generates. Could be wrong though as those images were good evidence that Vray can do strange things as well. Even so, I still think Vray is a superior displacement renderer.

By the way, why do all the threads in this forum always come to an abrupt halt with no conclusion/solutions? Seems to be a frequent trend here, and is highly annoying lol.

PS: Just thought of trying something. Why not take the generated alpha map in Zbrush and apply it to the model as a texture? Then you could paint out any distortions. Oh wait... maybe not. Can Zbrush apply 16-bit maps as textures or only 8-bit? Maybe this idea would work with another texturing program (Deep Paint, Bodypaint, etc)? Sorry, thinking as I go here...

[GeneCrucean]

By the way, why do all the threads in this forum always come to an abrupt halt with no conclusion/solutions? Seems to be a frequent trend here, and is highly annoying lol

Hehe, I was wondering the same thing.

Well, first things first. I noticed that if you export the displacement maps from the texture dialog no matter the file type you get an 8 bit texture and a bigger file size... If you export from the alpha dialog you get 16 bit maps and smaller file sizes. So my question is how are you exporting your maps out of Z?

[Trapezium]

By the way, why do all the threads in this forum always come to an abrupt halt with no conclusion/solutions? Seems to be a frequent trend here, and is highly annoying lol.

What an overstatement

[Steve_Green]

The maps are being exported from the Alpha panel, and Max says they are 16bit. I seem to get better results when using a negative RGB offset in the bitmap rather than using the offset in the displacement modifier.

- Steve

[vlado]

Try playing with the blur and blur offset parameters of the bitmap. Make sure Filter map is on in VRayDisplacementMod.

Best regards,
Vlado