Reprojecting UVs?

# 1 20-11-2009 , 09:43 PM

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Not sure if this is the right place to ask this. Ive said elsewhere on here that I've been looking at zbrush lately. I made this model and learned a method for creatinga nd exporting a displacement map. Having got back into maya, I set up the render and after a few tweaks ended up with the first image. I had no colour map however, and wanted to try to make one quick as an experiment. I planar mapped the model, but as you can see from the second picture im posting, its messed about with the subdivision of the model. Any ideas of ways around this problem. You can assign more than one set of uvs to a mesh cant u?

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# 2 20-11-2009 , 09:44 PM

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and the same model with displacement map still applied, approximation editor e.t.c, but with a newly created set of uvs and colour map...

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# 3 21-11-2009 , 01:04 PM

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how is the uv conected to the shader, why did you not let zbrush create the uvs after you created displacement map

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# 4 21-11-2009 , 02:42 PM

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I wanted to do the colour map in photoshop. I (is it) a.u.v'ed (?) the uvs in zbrush to do the displacement map, but you dont get something to work with like when you create a map in maya do u?. Am i making sense?

And because my shader had the displacement map applied, which was created from one set of uvs, would it not have messed it up if I applied another map (colour) based on a different uv layout.

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# 5 21-11-2009 , 08:00 PM

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ok. Now I'm really confused. It turns out that there was no displacement map at work at all on the above renders. All the work was being done by the approximation editor. Is there anyone who understands the process of creating and taking a displacement map from zbrush and rendering in Maya? I have followed all the resources I have found on this but theres obviously something still going wrong somewhere...

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# 6 21-11-2009 , 08:32 PM

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I have only done this once before but if you walk me through what you did mybe I can help, ps could you include a pic from zbrush to see what you are trying to acheive............dave

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# 7 21-11-2009 , 09:09 PM

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Hi dave. Thankyou. I have 'Z-Brush Character Creation, Advanced Digital Sculpting' book, by Scott Spencer. In the displacement chapter (chapter 9) he talks about the different types of maps, 16 bit, 32 bit floating point, multiple 32bit maps e.t.c. He reommends 32 bit floating point which I created and exported via the multi displacement 3 plugin for Z-Brush. Then, on the DVD included with the book there is a batch file which you can drag and drop your files onto to convert them. The displacement file was coming out of Z-Brush in TIFF format. What this file does is convert them to .map format via the command line, an automated process and made kind of sense to me as I have heard about mental ray's preference for this file format before...

...deep breath....

So then in maya I set up the approximation editor and the shader. Now on the DVD with the book I mention there is a short tutorial on there covering this process, again by Scott Spencer. However it isnt clear what file format he exports out of Z-Brush but he doesnt convert it to a .map, its still a TIFF, not sure 16 or 32 bit. He also sets up his approximation editor a little differently. He creates one for displacement and one for subdivision. In the book he just uses Subdivision. Plus he uses slightly different settings. On the video he goes for length/distance/angle, in the book he goes with parametric. So there are all these factors which could be at play. Thats all relying on the fact that I created a successful displacement map in the first place. Again, I did this by following the books instruction so Im assuming I have. I have tried several variations of the above settings, different approximation settings and values.

This is the picture of the ztool I generated the map from. This is at level 6 or 5. I generated the map off of level 1. And it is the exported level 1 obj I am trying to put the exported map back on in maya.

...deep

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# 8 21-11-2009 , 09:17 PM

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p.s, i didnt mean to complicate things by using a different model from the previous pictures.

...so I guess the map must be doing something in creating those wierd artifacts. So im guessing the problem is with the map rather than the maya set up. I know about flipping the map in the v-direction, I checked the option to do this in the z-brush export options so as far as I know it has been flipped. As I understood it aswell, when using a 32 bit floating point displacement file, scaling wasnt an issue either. I have read there are maybe some option sto constrain the scaling and proportions when exporting OBJ's from z_brush, but I just exported straight from the tool menu, understanding scaling shouldnt be an issue. HHmmm, maybe that something I should check.

This is all im getting so far...

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# 9 21-11-2009 , 09:22 PM

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the picture you supplied from zbrush looks nothing like the one you first posted is that correct? or are you trying to get the first post effect?........dave

ps. yes there are some things you must do if you want to change the scale, if you have change the scale of the model this is most likely your problem.........dave

Last edited by daverave; 21-11-2009 at 09:26 PM.

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# 10 21-11-2009 , 09:28 PM

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yes it is a different model. Having the same issues with both.Im not really rescaling it though. On import in maya I am just leaving it as is.

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# 11 21-11-2009 , 09:36 PM

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well. I dont think this looks right. This is the 16 bit map in photoshop, the 32 bit one looks exactly the same but with less contrast

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# 12 21-11-2009 , 09:37 PM

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hmmmm

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# 13 21-11-2009 , 09:40 PM

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ben will get back to you tomorrow, having a drink,
that is what it should look like.

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# 14 21-11-2009 , 09:55 PM

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I may have found the answer!!!!!!!!!!!!!!!!!:attn:

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# 15 22-11-2009 , 01:29 PM

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The problem seems to have been with the settings in the displacement exporter in Z-Brush. I was reading about the differenc between 16 and 32 bit maps, and where id tried the 16 bit type first of all, when I then switched to 32bit, the 16 bit type was still checked to on. So I was creating two maps at once which I guess were messing each other up.

As for the grid like look of the map above. A guy on zcentral said thats what it should look like too. I know that when you create uv maps in zbrush they do have that broken up tiled look, but actually the displacement map Ive had success with looks a lot more like what it represents. In the tutorial video I watched aswell, the displacemnet map for a character, when opened in photoshop, looks recognisably character like, you can see the eyes mouth nose etc. I wanted to post up a picture of what my displacement map looked like, but opening Tiff's in photoshop, i cant save out as a jpeg. But this next picture is the result I got in Maya, and the map for it looked like a load of squiggly lines with arrow heads, not the grid type thing above???

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Reprojecting UVs?

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