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View Full Version : 1st Zbrush attempt, what went wrong?


capone_adam
09-24-2006, 02:58 PM
Just tried rendering a normal from my HIGH and putting it onto my LOW. Projection seemed fine, no overlapping. With 512 size render you get some nice shape but its really messy, with 2048 its nice and clean but loses shape. Also what have I done wrong with the back of the neck?

So, yeah, if anyone can point out any of my 'n00b' mistakes it would be much appreaciated.

http://i93.photobucket.com/albums/l69/kenman2626/2.jpg

BenEoff
09-25-2006, 02:49 AM
Seems like the quality of the normal map is being rendered pretty low. Are you using zbrush to render out the maps? Maybe try xnormal? I've been using that and I love it.

Squirmy
09-25-2006, 02:59 AM
The uvs look a tad streched. Did you use a checker texture when flattening them? I get that seam sometimes to, usally I just keep rotating and flipping the uvs and that fixes it.

tin-tin
09-25-2006, 05:01 AM
To me it seems like the renderer doing something ugly with the nmap, try exporting to a game engine or some realtime shaders. Also it has flipped the one of the channels on the back seam.

hakanpersson
09-25-2006, 07:12 AM
like the renderer doing something ugly with the nmap

Agree. That is the reason for sure

capone_adam
09-25-2006, 07:53 AM
Mistake : Do not know how to delete post

capone_adam
09-25-2006, 07:58 AM
Thanks for the advice,

I thought maybe my zbrush model was not defined enough so went back and did a new zbrush pass andn especially tried to define the mouth more. As you can see it didn't really work. So maybe you're right, its my renderer? I am using direct X in max's viewport.

Oh and as for the squashed UV's. I did put a checker map on it but the only way I could keep the squares square was to squash it as much as I have.


http://i93.photobucket.com/albums/l69/kenman2626/latest2.jpg

braincell84
09-25-2006, 12:15 PM
Are you sure you're exporting the normal map when you are at the lowest subdiv? If yes, make sure you "store MT" before you start editing the piece and then switch MT (at lowest subdiv) when making the map. There are tutorials for this at zbrushcentral, so in case you went through them other things may be wrong. But from the look of the errors you're getting, it looks like youre exporting the map from higher subdivs.

The seam at the back of the head appears in max for me but when I load it in my engine there is such a function called "Compute normals" and it will reapply the normal map propperly to the mesh. The seam at the back of the neck is caused because the triangles are ordered differently (in their vertice order) but the normal map is the same. So either use a different shader or find a compatible engine.

Jaidek
09-25-2006, 01:37 PM
capone_adam, have you tried the ZMapper plugin for ZBrush? Its simple to use and creates perfect normalmaps, here's the link: ZMapper (http://206.145.80.239/zbc/showthread.php?t=031281)

Good luck!

BenEoff
09-25-2006, 04:40 PM
As for uvs, the nice thing about normal mapping is that is projecting onto the lower poly geometry and if you stretch or squash a poly, it doesn't particularly matter, it will still normal map correctly (don't get too crazy, though, as it still needs the pixel space to get the detail in). With normal maps, having perfect uv's is no longer a big concern unless you're just picky like that. And I highly recommend using xnormal, it can handle extreme detail, and it's very fast and free.

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