stbenge wrote:
> Kirk Andrews wrote:
>> What kind of
>> compositing are you doing?
> 
> I use Rune's illusion.inc file which lets you place an image into a 
> scene based on the camera view. I do this with the beta version of POV, 
> because it supports the .hdr format. I will explain my method in more 
> detail later; I'm in a hurry!

Kirk, here's the link leading to Rune's illusion.inc file:

http://runevision.com/3d/include/

This is one of the most versatile include files I've ever used. I have 
modified the code to work with HDR images, but I may need to contact 
Rune for permission to post it.

The basic idea for compositing images in POV is to pre-render parts of 
the scene and paste them back onto the objects for another render pass. 
For instance, in this scene of the clay/stone guy I rendered the 
height_field without anything in front of it first. I simply added 
no_shadow to the stone character. Then I projected the HF render back 
onto the HF, and rendered the character along with it. At this point I 
had two renders, one of just the HF rocks, and another with the rocks 
and character. I applied the HF render to the HF, and the 
character+rocks render to the character. With both images applied their 
respective objects, I then rendered the scene with high-sample focal 
blur, which took a ridiculously *short* amount of time.

It's better to use HDR images for all this, which is why you may want 
the modified illusion.inc code. It's also important to render the 
backdrop first, and render the front objects in steps, so that you do 
not end up with any strange outlines. You can get away with doing 
partial renders. If you use this technique for reflecting or refracting 
objects, be sure you are able to cope with possible inaccuracies. Also, 
using this method for focal blur+grass or similar objects may be 
exceedingly difficult. That is, unless you don't mind the horrible 
artifacts.

I hope this helped. I *should* make a tutorial illustrating this method, 
though I need to contact Rune before I do so.

Sam

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