Micke

01-01-2001, 01:22 PM

Hi GL coders.

I have a big problem with a little project im working on.

I have a rocket placed at a launchpad and a camera that is attached to the rocket and rotated around it using the moiuse .

The camera always faces the rocket . Quite standard approach I think.

So first I set the camera , translates the camera zoom factor and draw the rocket .

I aslo added some inputs with the cursor kays so you can rotate the rocket .

All rocket rotations is done by using matrices and all this works fine.

After drawing the rocket I draw the launch pad and after the launchpad I draw some smoke and some rocket flames that comes out of the rocket .

All this works fine until the rocket takes off . As the camera is attached to the rocket the world is translated after drawing the rocket . So I used a separate translation matrix for the rocket that I multiply with the rotation matrix for rocket , I dont want to translate the rocket rotation matrix , right .

After that I pull out the 12,13 and 14 element of the resulting matrix and use those values to translate the ground and launchpad . Really smart , I thougnt .

The problem is that now the world rotates around the rocket instead of being translated according to the rocket direction .

I hope someone could help me with this one .

Maybe I done something totally wrong here , Ive only used GL for two months now.

( Im a former Direct3D user , and my own opininon is that Direct3D SUCKS! )

Micke!

http://www.opengl.org/discussion_boards/ubb/cool.gif

( Couldnt resist in using one of those )

I have a big problem with a little project im working on.

I have a rocket placed at a launchpad and a camera that is attached to the rocket and rotated around it using the moiuse .

The camera always faces the rocket . Quite standard approach I think.

So first I set the camera , translates the camera zoom factor and draw the rocket .

I aslo added some inputs with the cursor kays so you can rotate the rocket .

All rocket rotations is done by using matrices and all this works fine.

After drawing the rocket I draw the launch pad and after the launchpad I draw some smoke and some rocket flames that comes out of the rocket .

All this works fine until the rocket takes off . As the camera is attached to the rocket the world is translated after drawing the rocket . So I used a separate translation matrix for the rocket that I multiply with the rotation matrix for rocket , I dont want to translate the rocket rotation matrix , right .

After that I pull out the 12,13 and 14 element of the resulting matrix and use those values to translate the ground and launchpad . Really smart , I thougnt .

The problem is that now the world rotates around the rocket instead of being translated according to the rocket direction .

I hope someone could help me with this one .

Maybe I done something totally wrong here , Ive only used GL for two months now.

( Im a former Direct3D user , and my own opininon is that Direct3D SUCKS! )

Micke!

http://www.opengl.org/discussion_boards/ubb/cool.gif

( Couldnt resist in using one of those )