Shadowgun's character/semi-dynamic shadows

Unity Engine
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1

http://blogs.unity3d.com/2011/06/08/advanced-shading-and-lighting-for-mobile/

“Caustics from the light passing through the green fluid, character shadows and rotating ventilator shadows were simulated with textures projected onto tight geometry (to keep the fillrate requirements low) and then animated in the shaders.”

I’m looking for more details about the bolded portion, in particular. How are they projected? What does he mean by ‘tight geometry’? Anybody have any insight?

edit: the autor of the blog post got back to me – he directed me to this video: http://video.unity3d.com/video/3709506/unite-11-shadowgun-rendering :slight_smile:

2

To me it sounds like he’s saying they used alpha in textures to simulate light beams, only did it on smaller areas of geometry(to lessen fillrate drawing performance hits) and used UV coordinate animation to make it appear to move or rotate or whatever.

3

Yeah, by ‘tight geometry’ he just meant that it tightly fits the shape of the shadow so that there’s no extra geometry with 0% opacity. The geometry for the blade’s shadows rotates along with the fanblade as a normal rotation – don’t think there’s any special UV animation going on.