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32 bit Negative value displacement maps

Posted: Fri Sep 25, 2015 1:34 am
by Raoul
Hi All,

I've received some models out of Zbrush with accompanying displacement maps.
Only problem is the disp maps are 32 bit with Negative values. So when you look at the image it has large black areas that look flat but actually have data.
This is the standard way Zbrush outputs disp maps in 32 bit.

I can't seem to get octane to read that information.. so it just comes in flat for those negative areas.

Does anyone know a way to convert those negative values so they become visible in the positive range..
Or even more useful.. a way to get octane to read those negative values?

It would be useful in the future for octane to support this format as Zbrush is a common tool and a good workflow would be very useful.

Thanks for the help.

Re: 32 bit Negative value displacement maps

Posted: Fri Sep 25, 2015 11:34 am
by atome451
Hi Raoul,

It's really a tricky and poor solution but you may play with Levels > Output Levels in Photoshop (in my old Photoshop CS 5.1 it works like that, maybe there is new possibilities in newer version). By moving the black cursor to the right, you'll compress intermediates values and should be able to restore the negatives values to the positive side. It a poor solution because you'll loose intermediate values, but with 32 bits it should work...

I'm also searching an utility to convert signed Bitmap to unsigned. It should be probably a far better solution in this case... If someone know a solution, i'm interested... :roll:
32b-levels1.jpg
32b-levels2.jpg

Re: 32 bit Negative value displacement maps

Posted: Fri Sep 25, 2015 2:35 pm
by aoktar
Here is a topic about it:
viewtopic.php?f=33&t=50300