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Quaternions Again

a2k · 2000-05-26T10:59:50

i''m testing out Jeff Lander''s quaternion code, and i figured if it works in his demo, it should work in my code. it turns out that when i convert to matrices and rotate in my program, it does some totally funky stuff, like it "springs" back into place when stopping, or if you give it an extreme angle, (not necessarily at a 90 deg angle) it goes schizo, and finally uncontrollably unrecognizable. this is actually a continuation off a quaternions topic i had posted, and now i''m outta finals and all those projects, i''ve had time to get back to quaternions. the code goes something like this: quaternion qpitch quaternion qroll quaternion qyaw quaternion qtemp axisangletoquat(&pitchaxis, pitchangle, &qpitch) axisangletoquat(&yawaxis, yawangle, &qyaw) axisangletoquat(&rollaxis, rollangle, &qroll) multiplyquaternions(&qpitch, &qroll, &qtemp) multiplyquaternions(&qtemp, &qyaw, &qtemp) Matrix matrix quattomatrix(&qtemp, matrix) //the axes are also initialized to these values rollaxis = {0,0,-1} yawaxis = {0,1,0} pitchaxis = {1,0,0} rollaxis = rollaxis * matrix; yawaxis = yawaxis * matrix; pitchaxis = pitchaxis * matrix; help is gladly appreciated, and to those who know of my dilemma already, i''ve utilized the code, (except tc''s getpresentangles so far) just to get an object rotating on arbitrary axes. it works fine if i load in the world coord axes into the axisangletoquat function, but it gets screwed up when i put in an arbitrary axis generated from the matrices... a2k

General and Gameplay Programming Programming

Started by a2k May 24, 2000 01:07 AM

10 comments, last by a2k 24 years, 7 months ago

a2k

Author

124

May 26, 2000 10:29 AM

cool. i''d like to see the "real" one.

a2k

------------------General Equation, this is Private Function reporting for duty, sir!a2k

WickedMystic

122

May 26, 2000 10:59 AM

A2k, about your question.

You will somehow have to ''store'' the orientation of your ships if you want yaw, pitch and roll to work properly.

You can do this for example by rotating the mesh and storing it over the ''old'' one.. this is something you DON''T want to do because due to numerical errors occuring when rotating the mesh will get deformed over a long period of time... So you always keep the original mesh and rotate from that.

The cool part is that the orientation is actually stored in the 3 ''extra'' vectors you added for rotating around. TC''s code gets the ''euler'' angles to rotate the mesh with from those vectors.

I hope this makes any sense

I am not really good at explaining this.

WickedMystic

Quaternions Again

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Quaternions Again

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