Remco de Korte wrote:
> 
> I have an origami-object that is made with CSG. Every fold is a new sit of
> clipping and rotating. I have made some aeroplanes this way and it works out
> fine. The trouble is, they're terribly slow to render. I understand that since
> each new manipulation cuts the object up in more parts the problem is here
> somewhere. I have tried optimizing it but nothing seems to make a significant
> difference. I think I'm overlooking something obvious, perhaps it would help if
> I did something with bounding boxes but all the things I have tried didn't work
> or at least not very well.
> I have posted a scene file to binaries.scene-files hoping someone will check it
> out and be able to make it work faster. I've commented out some light_sources
> and that helps but not really very much.

Well, from a quick render and some reading of your code,
it seems you are multiplying the basic object, a union of two boxes,
inside more and more complex construct.

I noticed a lot of clipped_by and I'm pretty sure that you
may instead use an intersection , thus reducing the bounding boxes.

On the same way, given the pyramidal explosion of your construct,
I wonder if disabling the bounding box would not give some speed-up.
(with 8 stages using two objects, you have about 2^8 (=256) basic objects, 
i.e. 512 real box and the whole hierarchy of bounding box:
512+256+128+64+32+16+8+4+2+1 = 1023 !! 

Given the compactness of the object, when a ray it one box, it may 
as well hit the others... so you probably end up doing 1023+512 box intersection
per ray. (may be not, but I do not remember that clipped_by was also 
taken into account for the bounding box [source is too far away for me at this
time])

You could also accelerate the rendering of the background by
doing an intersection with a box in which you know your origami is in
(side effect on the top bounding box: it is smaller; The box should 
of course never show itself, as the origami is smaller and inside.)

I let you do the experiments.

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