What is the difference between the “preview” in the “Tool Palette” and the “Current Tool Preview” in the “Draw palette”? What is the purpose of each?
Here are the answers from the online documentation:
Draw >> Preview is found on http://docs.pixologic.com/reference-guide/draw/
The Current Tool Preview shows you the shape and color of the current tool. You can drag within this window to see how the tool looks in a different orientation. Changing the orientation in this window has no effect on the tool or canvas. Click the + button to turn the preview clipping plane on or off. Click the arrow button to set this previewed tool in motion, rotating constantly; change the speed of the rotation by dragging.
Tool >> Preview is found on http://docs.pixologic.com/zbrushcore/reference-guide/tool/preview/
The Object Preview window displays the current 3D model. Also displayed is the clipping plane, showing how the object relates to an imaginary plane at the point where the Z axis (front – back) = 0.
Click and drag to change the orientation of the tool; drag the tiny crosshairs to change the object’s center. Hold the SHIFT key while dragging to snap its orientation to the nearest 45-degree angle. To hide or show the clipping plane, click the ‘+’ button in the upper-right corner. To freely spin the object preview, click the arrow button, and change the speed of spinning by clicking and dragging in the window.
So the big difference is that one is strictly a preview while the other can be used to change the model’s local coordinates.
You can see this in action by having a model in Edit mode and making a change to the Tool >> Preview, followed by pressing Store. The model on the canvas will instantly change position and/or orientation to match the change that you just made.