Sunday, August 13, 2006
Did a little more tinkering with invisiprims and occlusion culling. (Remember, you can find more information on invisibility prims here and here.) And, while I was at it, I played around with FRAPS a bit, too.
The experiment illustrated below is pretty straightforward. I made a 10x10x10 hollow cube and set it up with an invisibility prim script. Then I walked inside and took a look around.
It did a fairly decent job of hiding the surroundings, provided I didn't move the camera too quickly. Interestingly, the patch of ground that still shows when the invisiprim is active is somewhat larger than 10 meters across. As touched on in the previous entry on this topic, opaque prims that are only partially in the occluded field of view are fully rendered. This evidently applies to the ground, as well. Since a portion of the ground patch was inside the cube with me, it wasn't blotted out.
Not a particularly useful discovery, but interesting, nonetheless. Might be worth further experimentation, if someone wanted to make an invisiprim window for their ground-level home. You could place the invisiprim window (and the associated wall) at the edge of a ground patch (perhaps located by looking for pattern repetition in the ground texture?), to avoid unsightly strips of ground in your carefully sculpted and culled field of view. As noted by Ami Chyan in the previous entry, an invisiprim window effectively converts any view into a kinda, sorta ocean view (provided you are close enough to sea level to see it). I'm tempted to go in with something like this myself, just to recapture a portion of my own lost ocean view.