[Bf-committers] Sculpt optimizations

[Benjamin Tolputt]

On Sat, Oct 17, 2009, Nicholas Bishop wrote:
> Basically the patch adds a coarse BVH for sculpt mode. The BVH is used
> for finding where the sculpt brush is (so no more copying the OpenGL
> depth buffer!), for finding vertices within the brush area, and for
> partial redrawing. This gets rid of the nasty linear performance (in
> relation to number of verts) that sculpt previously had.

Removing the linear performance hit is the best thing I've heard about
sculpt-mode for some time. Is the BVH calculated across all vertices or 
just those in the visible frustrum?

Regardless of that, being able to sculpt with non-linear performance
across a sub-divided mesh up to the limit of the machine's memory (as
opposed to the CPU) will be an incredible improvement. Blender will
never be a replacement for Z-Brush, but if this is as good as it sounds
- it might become Pixologic's open-source cousin :)

Now if only it were possible to hide/show polygons in a consistent
manner across multiple levels of the multi-resolution modifier. Being
able to step easily between form & detail whilst sculpting is nigh on
essential for speeding up the concept sculpting workflow in Blender
(over the linear performance). In other applications, as with Blender,
hiding what you don't need to sculpt enhance performance. The
unfortunate side-effect of this is that it limits you to a single level
of detail in Blender (at the moment).


-- 
Regards,

Benjamin Tolputt
Analyst Programmer