Converting bullet matrix

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Katachi
Posts: 10
Joined: Thu Mar 27, 2014 1:49 pm

Converting bullet matrix

Post by Katachi »

Hi,

I am trying to include bullet into my project for Cinema 4D (aside from the native c4d). It works fine but it seems bullet is using a different coordinate system.

C4D is using a left-handed one which means:
x > 0 = to the right; x < 0 = to the left
y > 0 = to the top; y < 0 = to the bottom
z > 0 = into the screen (back); z < 0 = out of the screen (front)

For now it seems to me the bullet x-axis is pointing to the left > 0. y-axis definetly seems to be pointing up > 0 in bullet. And the z-axis seems to be pointing into the screen.
What are the actual directions of the bullet coordinate system?

Thanks in advance!
Katachi
Posts: 10
Joined: Thu Mar 27, 2014 1:49 pm

Re: Converting bullet matrix

Post by Katachi »

I just read in the manual that it is right-handed, but it does not say anything about the directions. I used the debug drawer of the openGL demo to draw the shapes I am inputing and indeed the alignment of the shapes are flipped from the ones in C4D (when naively converting c4d rotation matrix to a bullet matrix). The image in the docs is not very helpful, but if I had to guess, it looks as if only the z-axis is flipped (pointin out of the screen if z > 0 instead of into the screen as in c4d).

Anybody able to confirm the handedness of the bullet system as I describe it?

Thanks
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