Hi comunity, can someone to help me? I am trying to do this mathematical things:
1-I have balls (or spheres). Between each pair of balls I have to put a connection (a long cylinder mesh with a small radius) that connects a pair of balls. Each cylinder has vertical orientation (0,-1,0).
2-I have to create 2 matrices. One matrix position to put the cylinder at the center of one of the pair of balls, and a matrix rotation to rotate this cylinder to connect this pair of balls. The cylinder has distance=Dist(center ball1, center ball2).
3-to do this I have this code:
void IniPosRotCylinder(int iball1, int iball2, int icylinder) {
float uv, modu, modv, angle, cos;
Vec u(0, 1, 0),v,uxv; // u=vector initial cylinder with no rotation

//---------- calcule angle vectors u,v -----------------------
v = Gl.c[iball2].pos - Gl.c[iball1].pos; v.normalize();
uv = Dot(u, v); // dotproduct = u.x * v.x + u.y * v.y + u.z * v.z;
modu = 1; modv = 1; // modulus of u,v (directly)
cos = uv / (modu * modv); angle = Acos(cos); // in radians

// get normal to plane u,v
uxv = Cross(u, v); uxv.normalize();

//--- calculate matrix position of cylinder
Matrix m1(MatrixIdentity);
Vec pos = Gl.c[iball1].pos; // ball pos
m1.setPos(pos);

Matrix m2(MatrixIdentity);
m2.setRotate(uxv, angle);

//--- Put cylinder to matrix position m1 and rotate by matrix m2
Gl.cnx[icylinder].mt = m2*m1;
}

this picture try to explain this:
   

In a other 3D engine (TV3D) I could make this with the function:
   

But I want to do this with Esenthel engine. I suppose that I need to keep in mind the center position of cylinder before I put to it exactly at center ball (p1). Note: u=initial cylinder vector rotation, v=vector between p2-p1.

I am sure it's not easy to do, but I did this in the other engine. In Esenthel perhaps is possible to do this in a other way, perhaps in a few functions.

I hope with the pictures the problem is understandable.
Thanks very much for your attention.

you can use Matrix().setPosDir or setPosUp

Thanks, I have used instead this code:

Vec v2 = (Gl.c[ibola2].pos-Gl.c[ibola1].pos) / Vec(2);
Matrix m1(MatrixIdentity);
m1.setPos(Gl.c[ibola2].pos-v2);
Matrix m2(MatrixIdentity);
m2.setRotation(Vec(0,0,0), u, v);
Gl.cnx[iconex].mt = m2*m1;

and it works perfect.
   

Another thing. I can not type many keys in the message box with my spanish-catalan keyword correctly. for example when I press key shift+8 to type "(" instead appears "¿" character.

Looks like the engine doesn't use the WM_CHAR message sent by the os.
Because this would take into account different keyboard layouts...

maybe you need to create a font that supports your characters first?

The issue happens while I am typing in the message of the forum, nothing in relation of the engine, but the cause is to execute perhaps my application. Solution: restarting the computer, for example. But now I can type with no problems! Things that happens sometimes...