Zbrush MRGBZGrabber Brush Question

Greg DAlessandro

Does anyone know why this is happening?:

This is my obj that I imported into Zbrush ZR7


I use the MRGBZGrabber, duplicate the Standard brush > use the resulting alpha from the mrgbzGrabber > drag the brush with alpha onto a polysphere but instead of something looking like this: (not the shape, but something similar to this amount of depth)


I end up with a flat square like this:


Does anyone know what I am doing wrong/how to correct this? Thank you.

CheeseOnToast

First off, it's easier (and better) to make alphas like this positive rather than negative. That makes the zadd and zsub buttons behave as expected. To fix this one, rotate your object 180 degrees in the x or y axis, then go to the tool>display properties option and click "flip". That'll give you an positive spike instead of a negative one.

Set up your document to some square dimensions. Hit the "frame" button, then zoom in until the tool fills the document with no empty space around it. Grab the alpha and assign it to a clone of the standard brush.

Turn the focal shift of the brush all the way down to -100. Change the lazy mouse settings to have lazy step around 0.1. That should do it.

Note if your source model has any negative dimensions, or a mixture of negative and positive, you need to play around with the alpha's mid point which you'll find in alpha>modify>mid value.

Joshua Stubbles

Also, if the border persists around your alpha (Cheese nailed a good process), you can also use the radial fade (RF) options in the "alpha" menu panel. You can set it to a value of 1 and it should soft-fade the edges out.

Greg DAlessandro

Thank you for the detailed replies, but how/where do you create a radial fade under the alpha menu panel?

CheeseOnToast

Alpha>Modify>RF