bsabiston

02-05-2013, 11:25 AM

Hello,

In my game I have a circle on screen indicating a steering wheel or direction pad. Depending on the position of the finger relative to the center of the circle, I want to move in that direction relative to my current 3D view. Given a 0-360 angle representing the position on the wheel, how do I figure out which way to move in 3D space?

I'm looking down on a 3D plane, and I want to move along it. I tried getting the Euler angles in YXZ order, so that it would give me the rotation around the Y axis of my current view. Then I changed that angle by the angle of my wheel. It sort of works, especially if I am down low, looking at less than a 45 degee angle. But up higher it gets out of whack. I am thinking this is because the Euler angles are not really a predictable way to measure? Or are they? I tried a similar thing with a quaternion for the camera rotation, but it did not work either.

Basically I am thinking that if I can determine an angle representing my current view's rotation around Y, then I can use that to figure out how to map my d-Pad direction to world space.

Thanks for any advice. There seems like there should be an easy way to do this, but my attempts have not worked so far.

Bob

In my game I have a circle on screen indicating a steering wheel or direction pad. Depending on the position of the finger relative to the center of the circle, I want to move in that direction relative to my current 3D view. Given a 0-360 angle representing the position on the wheel, how do I figure out which way to move in 3D space?

I'm looking down on a 3D plane, and I want to move along it. I tried getting the Euler angles in YXZ order, so that it would give me the rotation around the Y axis of my current view. Then I changed that angle by the angle of my wheel. It sort of works, especially if I am down low, looking at less than a 45 degee angle. But up higher it gets out of whack. I am thinking this is because the Euler angles are not really a predictable way to measure? Or are they? I tried a similar thing with a quaternion for the camera rotation, but it did not work either.

Basically I am thinking that if I can determine an angle representing my current view's rotation around Y, then I can use that to figure out how to map my d-Pad direction to world space.

Thanks for any advice. There seems like there should be an easy way to do this, but my attempts have not worked so far.

Bob