Not fully understanding creating 16 bit Alpha Depth Maps

[marcZ]

Hi,

Im trying to manually draw some geometric Alpha/Depth Maps. I understand bit depth ok, but my exports all seem to still be 8 bit with noticable banding when used as an alpha, even when Im setting the documents to 16bit grey colorspace.

I’ve tried exporting 16bit greyscales from Cinema4D, Affinity Photo & Designer, CorelDraw and Gimp. In corel, I also set the gradient steps to Max 999, but it makes no difference, Ive tried Linear workflows, no compression, everything I can adjust I have tried.

I’ve tried PNG, TIFF, PSD formats.

Nothing will work, I always get Noise even after 0.5-5 pix gauss blur, which looks like cheap mottled plastic finish, or I get distinct depth levels no matter what. Im using default 3dPlane subdivided to over 4 million.

I can use the smooth tool to get a perfect finish, so I know the resolution is there, but this somewhat destroys the edges of my shapes.

EDIT - Its not the automatic add noise option in zbrush
EDIT - Its not the dither gradients options in Affinity
EDIT - I checked an alpha made in GrabDoc and some I downloaded from Artstation, and the pixel values still register between 0-255 (although the doc is 16bit → as shown in Affinity)
EDIT - Applying a layer FX 3 px Gauss to my basic shapes, does eliminate the noise.

I still need a solution for Cinema4D export as I have some amazing tiling models I created that have a depth shader on them.

I have to ask, Does Photoshop handle this better?

How to draw custom depth maps without having to use the smooth tool in ZBrush?

[Spyndel]

Hello @marcZ ,

What version of ZBrush? If using an obsolete version of the program please make sure to upgrade. There were issues with alphas that were fixed over the last several versions.

Once you have upgraded to the most up to date version possible for your license, if you still experience the issue please contact ZBrush Support. Please be prepared to document your process and explain what you are trying to do.

Thank you!

[marcZ]

Latest version. The problem does not appear to be zbrush. I also did some tests with displacement mapping in Cinema4d with the same alphas, and had the same problem.

Having done lots more tests and pixel peeking, it is the output from all the programs I use that is the problem.

It seems that anything vector drawn that has a gradient on it, has some kind of dithering applied that just cannot be removed via preferences. Rendering from c4d also appears to have noise or dithering applied too on flat surfaces…

The only partial solution I can find is to use 16bit greyscale documents, export as 16bit greyscale, then apply a 2 - 5px gaussian blur. This loses a bit of definition, so I upped the size to 4096x4096 to bring it back.

But I am wondering how do other people make high quality alphas? or is it a standard thing to apply a bit of blur to smooth things out?