ZBrushCentral

3dmodels-> pixols-> 2.5d models?

ZBrush Artworks
#1

When I was newer to ZBrush, i wondered why it was that I couldnt edit my previosly made models once I had put them down on the canvas, and let them go. My question was answered by this: ZBrush converts the 3d model into pixols once the user lets go of the model on the canvas. This is useful in keeping ZBrush from being super-slow. Im now wondering if ZBrush also stores in its super-brain a 2.5 dimensional map of the image to retain the qualities of a 3d image when a new mesh is being put down.

David

#2

To be honest David, That’s the weirdest question I’ve ever heard. Of course now I’m intersted if aurick has an answer to it,Or someone from Pixologic. My guess is No, it a process of Conversion between 3D and 2 D. the two world’s don’t really meet, the computer just make’s it seem that it does…
David

P.S. Weird questions are a sign of brilliance or plain stupidity…Either way I’m right there with dude…

#3

Actually, ZBrush maintains a 32 bit depth map of the scene. Notice that we don’t call them “pixels,” but rather “pixols.”

Here’s the difference in what each “remembers”:

Pixels (used by 2D apps):
:b4: X position
:b4: Y position
:b4: RGB value

Pixols (used by ZBrush):
:b2: X position
:b2: Y position
:b2: Z position
:b2: RGB value
:b2: material

You can really see the fact that ZBrush tracks the full depth info of the object (including pixols that face away from the camera) in the example below.

I’ve activated ZMode in the Light>Modifiers>Shadow menu so that ZBrush would take that depth information fully into account. Notice that the shadow is properly shaped for it to actually be cast by a sphere when the light is coming from that angle? If the depth information for backward-facing pixols was lost when the object was snapshot, then you would see a curved front edge to the shadow and a straight line for the back edge.

Of course, telling ZBrush to make full use of that information does slow things down a bit. Which is why full shadows are only calculated during a best render. But the bottom line is that the full depth of the object does indeed remain!

#4

You learn something new every day… I’ve been using ZBrush since the first demo, and I still didn’t realize that the backwards-facing pixols were recorded, though now I think about ZMode, it seems obvious. :slight_smile: (Things always do, once you know them…) :wink:

Anyway, thanks for the clear explanation Aurick. :slight_smile: