Convert dMatrix to D3DXMATRIX

[KingSnail]

Hello,

I am a semi noobie game developer trying to integrate the newton engine into my engine for the first time,
so far I got some crazy flying boxes and broken collision,
But I believe I will get there. I want to know how to convert the dMatrix found in the dMaths library of newton to D3DXMATRIX.
I am following the tutorial and on the transform callback and I just need to make the final matrix that is sent to the shader to transform geometry.
Anyone can help?

[Julio Jerez]

teh dMatrix hav eteh same layout as a d3dMatrix. you can just copy the element member by member and it should be fine, i think

[KingSnail]

I tried both these methods, both give wrong results (crazy flying polygons)
Am I at least doing this step right? (The dMatrix is m_matrix)

ty->world_matrix._11 = ty->m_matrix[1][1];
ty->world_matrix._12 = ty->m_matrix[1][2];
ty->world_matrix._13 = ty->m_matrix[1][3];
ty->world_matrix._14 = ty->m_matrix[1][4];

ty->world_matrix._21 = ty->m_matrix[2][1];
ty->world_matrix._22 = ty->m_matrix[2][2];
ty->world_matrix._23 = ty->m_matrix[2][3];
ty->world_matrix._24 = ty->m_matrix[2][4];

ty->world_matrix._31 = ty->m_matrix[3][1];
ty->world_matrix._32 = ty->m_matrix[3][2];
ty->world_matrix._33 = ty->m_matrix[3][3];
ty->world_matrix._34 = ty->m_matrix[3][4];

ty->world_matrix._41 = ty->m_matrix[4][1];
ty->world_matrix._42 = ty->m_matrix[4][2];
ty->world_matrix._43 = ty->m_matrix[4][3];
ty->world_matrix._44 = ty->m_matrix[4][4];

////////////////////////////////////////////////////////
//Tried this too

ty->world_matrix._11 = ty->m_matrix[0][0];
ty->world_matrix._12 = ty->m_matrix[0][1];
ty->world_matrix._13 = ty->m_matrix[0][3];
ty->world_matrix._14 = ty->m_matrix[0][2];

ty->world_matrix._21 = ty->m_matrix[1][0];
ty->world_matrix._22 = ty->m_matrix[1][1];
ty->world_matrix._23 = ty->m_matrix[1][2];
ty->world_matrix._24 = ty->m_matrix[1][3];

ty->world_matrix._31 = ty->m_matrix[2][0];
ty->world_matrix._32 = ty->m_matrix[2][1];
ty->world_matrix._33 = ty->m_matrix[2][2];
ty->world_matrix._34 = ty->m_matrix[2][3];

ty->world_matrix._41 = ty->m_matrix[3][0];
ty->world_matrix._42 = ty->m_matrix[3][1];
ty->world_matrix._43 = ty->m_matrix[3][2];
ty->world_matrix._44 = ty->m_matrix[3][3];

[Julio Jerez]

what are you displaying a mesh tree.

I suggess to make a simpel mesh and render at the origin with an didentiry matrix, that will rule out the posibility that teh matriux is wrong.
My guess isthat the construction of the mesh itself is wrong

[KingSnail]

Hi, thanks for replies, It turns out I didnt have the currect matrix set on the body.

I now have another small question, how to convert from rotation quaternion to rotation vector.
I tried using the convert to euler angles method of the quaternion and it seems to work, but the cubes only rotate one way so I am not sure.

[Julio Jerez]

I now have another small question, how to convert from rotation quaternion to rotation vector.

what is a rotation vector?

[KingSnail]

Code: Select all

void Transform(const NewtonBody * body, const dFloat * matrix, int thread)
{
    BaseEntity * ent2 = (BaseEntity*)NewtonBodyGetUserData(body);
     Statue * ent = (Statue*)ent2;

   // get the position from the matrix
   dVector posit (matrix[12], matrix[13], matrix[14], 1.0f);
   dQuaternion rotation;
 
   // we will ignore the Rotation part of matrix and use the quaternion rotation stored in the body
   NewtonBodyGetRotation(body, &rotation.m_q0);

   dVector euler = rotation.GetXYZ_EulerAngles(); //I am not using quaternion and vector like in tutorial because I really dont understand quaternions, I am just using 2 vectors which later make a world matrix

   ent->mrot = D3DXVECTOR3(euler.m_x, euler.m_y, euler.m_z);
   ent->mpos = D3DXVECTOR3(posit.m_x, posit.m_y, posit.m_z);
}


[Julio Jerez]

if you use direct x why do you need euler angles? you can just copy the matrix into the d3d objects

[KingSnail]

I tried just copying it but it gives all sorts of artifacts,
But I mean the way I did it, is it correct?
Because if its correct I could leave it like this for a while and work on other collision things

[Julio Jerez]

to my knowledge the d3d matrix and the dMatrix have an one to one mapping, you should be able to just do
memcpy (d3dMatrx, newtonMatrix)
and it should work just fine.

[KingSnail]

Ok I did that and it works! thanks so much Julio