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leigh
11-08-2004, 11:36 PM
I hope this isn't a stupid question, but please bear with me because I'm still getting the hang of ZBrush. I imported a model made in another application into ZB, and then played around with the add and subtract brushes and all that to make some details on the surface.

But when I try to create a displacement map, it just gives me a blank gray image. Any idea what could be causing this? I am sure that I did not miss out any steps in the process...

:blush:

erilaz
11-09-2004, 12:01 AM
This usually means there is no difference in detail between the level of sub divisions, which may mean you are on the highest level of subdivision.... but I'm really just pulling at straws.... I'm fairly new to zbrush as well!

roguenroll
11-09-2004, 12:32 AM
steves workflow was great for me, I've had no probs, there were a few little settings, and tweaks to get the model ready.

http://www.stevewarner.com/Tutorial.../zBrushTut.html

seems down, email, I'll send it to you. its a flash tutorial.

John-Stetzer
11-09-2004, 12:42 AM
But when I try to create a displacement map, it just gives me a blank gray image. Running into the same problem with a model I did over the weekend; this was a new version of a model that previously provided good results, but this time through I'm also getting an all grey displacement map, and when I export the object back out of Zbrush I end up with geometry missing. Hoping to find a solution soon myself :^/...

leigh
11-09-2004, 12:42 AM
Thanks for the replies.

Erilaz - I already changed it back to the lowest setting :shrug:

roguenroll - heh thanks, I actually nabbed that off the web earlier, and was working with it. I followed every step and indicated and yet still I am getting plain gray displacements when I try to make them. I redid it all a few times in case I'd missed something out but I'm still getting the same problem :surprised

meats
11-09-2004, 03:37 AM
Leigh,

That's cool that you are getting into Zbrush, you will kick butt with it!

It does sound like there just isn't enough change to create an obvous map from.
It may be that there IS information in your map that you can't see - 16 bits can hold a lot of information. You can test your map in Photoshop by cranking the levels to see if there really is different values in it. You can also do this directly in Zbrush by going into the Alpha Palette, selecting your alpha displacement map then pressing Alpha> Make Tx (Texture). This will convert your alpha to a texture and place it into you texture palette. Then go to the texture palette and press Crop and Fill Document. This will fill the screen with your texture. Now you can go into the Render Palette and adjust the brightness/contrast using the Adjustments> Adjust settings. This is just to make sure there isn't hidden information. Realistically, if there is enough difference between the lowest and highest subdivision levels, you should easily see the different grayscale values.
Do a test with some major changes between the low and the high, really push in and pull areas on your model. Then do some high frequency deformation using the projection master and create a new displacement <adaptive on - smooth UV off - displacement mode ON>.
Post again if you have any luck.

John-Stetzer
11-09-2004, 03:49 AM
It may be that there IS information in your map that you can't see - 16 bits can hold a lot of information. That wasn't the case in my file; in the attached image the bottom two squares show a section of the displacement map (E) and the same section with an auto level performed in photoshop (F). Basically not getting anything generated as the difference between A and C. B shows the other bug I had, with the exported mesh missing geometry.

Joebount
11-09-2004, 05:16 AM
It might just be one f***ing vertex in any resolution that is very far away from its friends (they gray come from that since Z take the higher en lowest value for the values of the displacement map), so, you have to hunt this little bastard and put it back in its proper place. Yeah, a real pain in the a$$, it happens sometimes, I hope it helps.

roguenroll
11-09-2004, 02:26 PM
yeah that reminds of my problem, very similar, don't know if its related. I worked out and another suggestion was made.

http://www.cgtalk.com/showthread.php?t=174390

hope it helps, clicked morph target, switch twice, or
just click 'cage' button

leigh
11-09-2004, 02:47 PM
Thanks so much for all the helpful suggestions! I am sure that one of these solutions will do the trick, so I'll try each of them and hope for the best :D

I must say that I am so excited because ZBrush has finally clicked with me. It's taken AGES... I could just never get my head around the program 100% but now it's all fallen into place and I'm having an AWESOME time! :thumbsup:

Pentagramma
11-09-2004, 05:24 PM
Hi Leigh,

Im not sure if thats the problem, but are you adding the base geometry as a morph target before the disp map extraction? If you do this , and do the switch trick, it should work.

Zbrush absolutely rocks. Im sure youll have lots of fun with it. :thumbsup:

John-Stetzer
11-09-2004, 09:04 PM
Thanks for the suggestions given in the thread; unfortunately none helped in my specific instance. At this point I'm just going to assume that something got corrupted along the way and start over.

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