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Old 07-13-2012, 11:58 AM
saajaja saajaja is offline
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Join Date: Nov 2011
Posts: 14
You have to fake everything in virtual reality. Turning the lights up is done separately from casting shadows.

There isn't much perceptual benefit of having over-the-top realistic lighting. The Shadow.py module that WorldViz has works on dynamically changing objects, but it isn't very realistic. If you're working with static objects, or ones that don't completely change form, you can use images as shadows.

For two methods of doing this, if you're running Vizard 4 (3 might have it), press Shift-Ctrl-O and open gallery.py and tutorial_shadows.py.

gallery.py demonstrates a simpler method, but it only works if the object is casting the shadow on a uniform plane, like a human casting a shadow on the floor. The shadow helps the viewer understand where the human is in relation to the floor.

tutorial_shadows.py is more flexible, but it is limited by hardware constraints. Some graphics cards can support eight projectors (shadows) at once; mine supports three. It can cast shadows on nonuniform objects and account for their curvature.

Getting objects to cast shadows on themselves in realtime is just not something I've heard of anyone out there doing. The rendering just doesn't happen quickly enough to happen in realtime. Until hardware improves dramatically, we'll have to keep hacking.
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