Christoph Hormann <chr### [at] gmxde> wrote:
> Daniel Neilson wrote:
> >
> >  See the web page listed above. I've updated it with a couple of timing
> > results from Ingo's mesh maker macros.
>
> But everything below 100000 triangles is not very useful.

 Fair enough. I reran another render for the p_bretzel.pov demo mesh, but I
changed the Iter_U and Iter_V parameters of the parameter{} block to 500
and 2000, respectively (from 50 and 200, respectively).

On my 3.0GHz P4, the render/trace times were

 BVH Mesh: 31.40 seconds
 KD-Tree Mesh: 24.65 seconds

 Also of interest is the time to parse the scene using the two different
versions (this includes the time required to build the BVH/kd-tree for the
mesh)

 BVH Mesh: 710.95 seconds
 KD-Tree Mesh: 667.54 seconds

> My first comments:
>
> - while the kd-tree for the main scene objects is optional and can be
> turned on/off with options meshes seem always be using the kd-tree.

 That's true. For comparing the two I actually had two code bases. One used
the old mesh and one used the new -- exchanging the two is just a matter of
copying in the new mesh.* files and editing two lines in parse.cpp. I'd
figured it was a pretty safe assumption that no mesh would produce a
degenerate kd-tree. Easily changed, though. I'll see if I can't find some
time in the next couple days to alter that.

> - in contrast to meshes blobs don't have the kd-tree bounding.

 I hadn't even looked at blobs, actually. Didn't even occur to me that they
might be using a BVH. I'll see what I can do about altering that as well.

> - it seems faster in a lot of scenes but i had problems with others
> (isocacti.pov for example does not render).

 That's very odd. My version actually renders isocacti.pov just fine. Does
it print out any sort of errors, or does it crash, or does it render a
blank image, or... ? Perhaps something's wonky about your patched version?

> - your patch would be much better usable if you would not modify all
> source files (even if it's just the header).

 Fair enough. I'll do that with the next iteration of the patch.

-Daniel Neilson

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