Messed up with matrices

kulesz · 11-07-2011 12:17 AM

Hi,

It's a bit late and my head isn't working too well.
I try to draw a particle, which is attached to specific object bone (in example, torch - point is placed in the end of the stick).
I'm calculating the position with:

Code:

// matrix is the hand matrix (the hand position)

void drawParticles(Particles &particles, Matrix & matrix)

{

    SkelPoint* lightPoint;

    if (lightPoint = mesh->skeleton()->findPoint("lightPoint"))

    {

        Matrix a(*lightPoint);

        particles.matrix = a + matrix.pos;

        particles.draw();

    }

}

But the effect looks like on a screen (like the position isn't rotated by the item orientation).
Where did I messed up the matrices? ;-)

Driklyn · 11-07-2011 08:22 AM

Try using:

Code:

if (lightPoint = Players[0].cskel.findPoint("lightPoint"))

{

    particles.matrix = lightPoint->pos;

    particles.draw();

}

The cskel should already be rotated since it's animating with your character. Using mesh()->skeleton() will give you the non-transformed version (i.e. what you see in Model Editor).

kulesz · 11-07-2011 09:53 AM

But the lightPoint is the point in item skeleton, not the player skeleton.

Driklyn · 11-07-2011 08:56 PM

Yeah, good point, didn't think about that..

Here's a code snippet from an old project of mine. This was used to find the barrel direction and position of the gun the player is currently holding.

Code:

if (SkelPoint *point = skeleton->findPoint("barrel")) {

    barrel_dir = point->dir * matrix();

    barrel_pos = point->pos * matrixScaled();

}

skeleton, matrix(), and matrixScaled() belong to the gun (Game::Item). I believe this will help you out..

Messed up with matrices
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