Mike Williams <nos### [at] econymdemoncouk> wrote:
> The usual situations where manual bounding can be better are those where
> the intersection or difference of two large objects produces a small
> result.

Understood; I've used this trick before and it can yield massive speed gains in
some circumstances.

> Another factor is that the automatic bounding slabs are always aligned
> with the axes.

Presumably it follows that manual bounding shapes are transformed with their
parents and end up at angles, etc...?

> Mesh objects render so
> efficiently anyway that the gains would be unlikely to be very
> significant unless the mesh object has a large number of large polygons.

Hmm. I'll try to explain the source of my suspicions. I have a large number of
small meshes in a union (see my recent post in p.b.i). I'm using MegaPOV, which
draws bounding rectangles on the render window before it starts tracing - I
understand this is a representation of the vista buffer. All of the bounding
rectangles for my mesh objects seem to be much larger than the meshes. Is this
because of the way the vista buffer works or is it a symptom of inefficient
mesh bounding shapes?

I'm sorry I don't have any screenshots - I'll try get some tonight if it helps.

Bill

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