Re: Low latency video mapping on 3D objects
Re: Low latency video mapping on 3D objects
- Subject: Re: Low latency video mapping on 3D objects
- From: Erik Buck <email@hidden>
- Date: Tue, 19 Feb 2008 07:46:46 -0800 (PST)
I think you can map video to the sides of a cube without writing any code at all. I think there is a Quartz Composer example of exactly that. If not, use the Cube renderer in QC and map 6 video sources onto the various frames.
There are examples that show how you can drive QC inputs from your programs. Drive the cube rotation, position, and scale inputs to manipulate the cube.
I am unsure what you mean by "low latency". If you are concerned about human perception of latency, humans can only detect latency greater than about about 1/25 second if the human is not "in the loop". If the human is in the loop, e.g. the human is using a joystick to move the cube, 1/50 second is probably undetectable. If for some reason you need latency less than about 1/200 second, you probably can't use Mac OS X. The nature of the system and the OpenGL drivers will not reliably provide less latency. Drivers, the AGP or PCIe bus, and the design of the graphics cards limits the minimum latency.
For an experiment that will only take ten seconds, connect the mouse input source to the rotation inputs on the 3D cube in QC. Move the mouse around and see if QC provides adequate responsiveness.
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