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Monthly Archives: December 2011

So, there’s always this question of “what’s the difference between rotate THEN translate VS translate THEN rotate”?

DOES TRANSLATION VS ROTATION ORDER MATTER?

__YES IT DOES__.

If you do ROTATE THEN TRANSLATE, the effect is __spinning in place__, because ROTATE about axis first (we are still @ origin), then translate OUT to some point in space.

ROTATE THEN TRANSLATE, produces SPINNING effect


If you do TRANSLATE THEN ROTATE, the effect is __ORBITING__ around an axis, because it translates you OUT FIRST, away from the origin, then you rotate that new further point about the origin:

TRANSLATE THEN ROTATE, produces ORBITING effect


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I’ve seen this _more than once_ and always seem to look to the wrong things..

# Problem: patchy renders

# Diagnosis: Eye is TOO CLOSE to the surfaces when rendering hemicubes.

– turn OFF backface rendering (CULL THE BACKFACES!!)
– move the eye 1e-9 units in the direction of the eyeToLook vector (to move it JUST ABOVE the surface of the patch you are getting the hemicube for)