ZBrushCentral

Importing Bitmap textures with alpha channels

ZBrush Usage Questions
#1

Is there a way of importing a bitmap file - a .psd for example with its transparency intact.
Auricks tutorial:
http://www.zbrushcentral.com/zbc/showthread.php?t=20352
suggests:

“You can also use this technique if you have an image with an alpha channel. Import the color into the Texture palette and the alpha channel into the Alpha palette. The texture can then be painted using the alpha for control.”

Has anyone tried this? I can’t seem to get it to work for me. (Though I do have a history of missing really obvious things)

While I’m here. A related feature request:
Could a future version of ZB support PNG files with embedded transparency?

#2

you can import a psd. what he is suggesting is you split your psd. take the alpha channel and load it into the alpha slot of zb and the color version minus the alpha channel into the texture slot in zb. If you do that it should work.

oh ok i think I am getting what you said now dohhh. I may be mistaken but I think the alpha needs to be 100% black in the areas you want to be transparent. Zbrush I don’t think can keep the transparency intact. I haven’t tried loading one but it probably fills it with 50% gray? If you are in PS just make the transparent parts 100% black and it should work fine.

A pic example of what you are trying to do would give us a better idea of what you are doing though.

#3

It seems that if I import a psd the Alpha channel is ignored and ZB creates an alpha based on luminance which is not much use.
I have tried a little experiment where by I exported a transparent png to After effects and then rendered out its alpha and color texture as seperate files. This seems to work after a fasion BUT I seem to get black fringing when I apply the texture with the alpha. (Even at aa half) This is not quite as visible if you render out the colour texture again against a mid grey and gone if you extend your aw over the edges that are going to be transparent.
This is all a bit long winded and a lot of time could be saved If ZB had some way to remove the black from the matte as per Photoshop, after effects etc.

I guess I’m trying to find a quick way of cutting stuff out to apply as textures without the black fringing.

#4

its hard not to get that fringing no matter what you use.

I usually end up using PS with a white layer underneath the layer I want to use and I lower the opacity so I can see beforehand and get rid of any possible fringing.

you can use zbrush and photoshop (if ya got the memory) at the same time so you can separate your file into two files…color and alpha…and load them into their respective menus in zb. if you see something not working well in zb fix it and save in PS and it will autoupdate in zb.

another thing that sometimes gets overlooked is to make sure intensity is set at 99 or less. One thing to note too is that for some reason even if not using the transparent option for textures black comes out transparent on layers so make sure any black in your color version is 99.9% black.

hope that helps ya some.

#5

Thanks for the tips. Shame there isn’t a more integrated way to do this stuff.

I don’t quite understand about intensity being 99% or less. Surely this just makes the texture slightly transparent? Unless it is not rgb intensity you are referring to?