ZBrushCentral

Can't export 32 bit Normal map

ZBrush Usage Questions
#1

Hi all, I’m in my first days of using this amazing app (although I’ve owned it for years!) and I’ve done a very tentative amount of sculpting just to check on any workflow probs I may have between applications.

I can export a 16bit Displacement file but when I export my Normal map it comes into Photoshop as 8bit. If I hover over it in ZB’s texture window, it states that it is 32bit but when I click export and save as psd or tiff it always converts to 8bit.

This is via the standard Normal map pane, not ZMapper. I’m struggling to understand ZMapper and it always seems to lock up when I use it (could be because I’m in Parallels on Mac). But other than the depth problem, I’m finding the basic way works fine anyway.

#2

Normal maps are going to be 8-bit images. There is no need for them to be 16-bit or 32-bit. The 32-bit format is exclusively used for floating point displacement maps.

(Normal maps are RGB images rather than grayscale images. RGB images are limited in the number of color shades that are available, which in turn are limited by what the human eye can detect. They can’t go higher than 8-bit under normal circumstances.)

#3

Hey Aurick, I’m hoping that you pick up on this seeing as how it’s an old thread.

So I’m wondering if what you’ve just stated for normal maps also applies to color/texture maps.

I’m also noticing that when converting poly paint to texture that ZB lists it as being 32-bit but when exporting it converts it to 8-bit.

The reasons I’m curious about this is because I’ve just begun to dig into ILM’s OpenEXR format with Maya. I’m now rendering RAW 32-bit Floating point images with Mental Ray to the .EXR format and enjoying the additional exposure and white balance options that I get in post with either Photoshop, AE or Shake.

Therefore I was hoping to take one of my poly painted models and compare differences in MRay renders between an 8-bit textured model and a 32-bit textured one.

Thanks in advance. Hope you pick this up. Any clarification would be great!

-mike

#4

To try an clear up the confusion:

32 bit for displacement maps is 32 bits per channel, though with grayscale there is only one channel.

32 bit RGB for texture files is 32 bits per pixel. This is 8 bits per channel - 24 bits for RGB and a further 8 bits for an alpha channel. (In ZBrush the alpha channel is only available for embedded material indices.)

HTH,