Hi Acorn—

I commiserate with you that there doesn’t appear to be any easy way to “Drill” or “excavate” into a surface in zBrush mini core. If there were a negative value possible for the “pulling” tools, then you could push and displace an area, as you could in Sculptris, which was a free program zBrush bought and then made un-free ☹. If you look around, you might be able to find a copy of Sculptris, and as with any program that has any worthwhile features, you can export your results to something exchangeable with other programs…OBJ is not as robust as FBX, but but Sculptris and Mini core can export to OBJ.

That said, I think with the exception of brush tools found in larger modeling software (Cinema 4D comes to mind), there is another approach: Boolean operations. Boolean merging, subtracting and so on should be familiar with Xaraist…it’s just that the operations are performed on 2D shapes rather than 3D objects in modeling programs.

The attached image is my attempt at poking a hole clear through a sphere, and mostly failing, using Sculptris, and then and example of Boolean subtraction to get a “hole” in a primitive.

I think I’ll try to get into what a parametric surface is in my next post. Just about all the modeling programs out there (not CAD, but modeling) approximate a surface, and you crank up the resolution to make smooth surfaces. You’ll see straight vectors around a sphere, for example, that has a very low approximation of the surface.

My Best,

Gary

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