XM Magdalena 3D print, GGeorgy (3D)
LC #42 Pipers Alley

View Full Version : Controlling the Curvature of an Alpha Brush

06-01-2009, 11:22 PM
I really like the Alpha feature of ZBrush, where you can use a gray-scale image to paint 3D detail into a model.

BUT - I would like to control the curvature of the brush, if I can. I notice that if I use a perfectly flat brush, with no gradients, just one area of white, gray, and black, I can get a flat displacement in Maya or Max, but not ZBrush.

This is the image I'm using to do a test paint -


When I load it in the Alpha tool section of ZBrush, and paint with it in 3D mode on a simple plane, with the div's. way up, I get this -


By "control the curvature", what I mean is, I want a nice flat displacement. For example, this image where I used the same original gray scale image in the Displacement slot in Maya -


See, that's all flat. If I can, that's the kind of paint brush effect I'd like to get in ZBrush.

It looks like the default in ZBrush is to have the curvature, the way it's shown in the second image with the MatCap Red color object. Still, if I can I'd like to find out how to control the curvature, and how to make the surface co-planar, not radiused, like the Maya image.

So far I've found control over the intensity; the radius is less pronounced when the Z intensity is turned down. I'd like to find a way to have the Z intensity turned way up and still make it flat, like this final image from Maya -


06-02-2009, 01:42 PM
Try to adjust the focal shift.


06-02-2009, 01:56 PM
Try to adjust the focal shift.


thank you, that helps !

here's a partial screen capture of the result when the setting is "focal shift -100" -


I'd still like to learn how to make the surface completely flat, using the simple alpha image shown. I could probably set up a gradient to counteract the built-in curvature, but if there's another way, I'd like to find out what it is.

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06-02-2009, 01:56 PM
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