Lets you limit meshing to a bounding box.
[list][]This is especially intended to help you mesh the top surface of a fluid simulation.
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[]These controls can be found in the new “Region of Interest” rollout.[/:m]
[]Enabling “Select and Manipulate” in 3ds Max will show a gizmo to help you position the bounding box.[/:m][/list:u]
The box is currently world-space aligned and cannot be rotated, since Frost operates in world space.
The bounding box in the Frost UI is defined as a center point and X/Y/Z extents.
The Manipulator however allows you to
[list]
[*]Adjust each side individually by pulling on the red/green/blue ball handles to resize along one of the X/Y/Z axes
Resize both sides symmetrically by holding down the CTRL key while dragging a ball handle.
Move the gizmo along a world axis while retaining the box size by holding down the SHIFT key (“Shift the gizmo”, get it?) and dragging a ball handle
Resize the gizmo to a cube by holding down the CTRL+SHIFT keys to set all three axes to the same value
[/:m]
[]The gizmo also offers arrows an all 6 sides of the box which will move the whole gizmo a whole length with one click.[/:m]
[]The Center of the gizmo is marked by an asterisk handle which can be used to move the gizmo within the world plane most orthogonal to the view, adjusting two axes at once.[/*:m][/list:u]
Note that the gizmo manipulator will update the Frost meshing only if the checkbox to update on particle changes is checked. When unchecked (default), you can adjust the gizmo very quickly, then click the Update button to refresh manually. When checked, you can move the gizmo and mesh interactively, but this can be very slow with large data sets.
Also note that this is just an initial implementation of the Region Of Interest and we are aware of possible future optimizations to make it more efficient.
The original request was for a way to mesh a small part of a large data set for fast iterations while adjusting the meshing parameters, but as Paul mentioned, since it affects both the viewport and the rendering mesh, it could be used to isolate a user-defined region for actual production rendering.
All Region Of Interest parameters (center and size X/Y/Z) can be keyframed to animate the gizmo position and size over time.