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Piddu
09-08-2005, 11:10 AM
Hi there, How is possible to transform a world rotation in a local rotation?
What can i do?
Is there a particular algorythm?

thanks for help.

mlanser
09-13-2005, 08:28 AM
The tool that we use in both mathematics and in computer graphics for moving between coordinate systems is the matrix.
Fortunately it’s not particularly difficult math – go Google “Introduction Matrices” and you’ll turn up about a half-million hits that will explain the basics. I’m going to assume you’ve done so from here on out.

multiplying that matrix with a set of coordinates in one coordinate space turns them into the equivalent coordinates in another system.

if you're using direct3d, you might find this one useful:
http://pluralsight.com/wiki/default.aspx/Craig.DirectX/CoordinateSystemsTutorial.html

zhang
09-15-2005, 10:19 AM
You need to multiply the object's transformation matrix by the inverse of the destination object's transformation matrix. That will compute the first object's transformation in the second object's local sapce, just like you parent object to another in any 3D app.

Here is some basic idea:
(http://%0Ahttp://www.gamespp.com/tutorials/matrixTransformationTutorial.html) http://www.gamespp.com/tutorials/matrixTransformationTutorial.html (http://www.gamespp.com/tutorials/matrixTransformationTutorial.html)
http://www.siggraph.org/education/materials/HyperGraph/modeling/mod_tran/3d.htm

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