LookAt or FaceTarget function that works on X and Y axis

[bob]

I searched the board for a "LookAt()" function and found several but none worked properly for any camera position and for both x and y axis. So I was forced to engage my brain (which is always painful) and finally came up with this snippet that works, at least for me.

I'm posting it here just in case Florida is flooded due to global warming, and I somehow manage to survive after days of clinging to a rotting alligator carcass and eating dead lizards, I won't have to then, on top of adjusting to my new life in Georgia, figure this out again. Also, someone else may find it useful.

Code: Select all

        void FaceTarget( const CSiVector &v )
        {   if ( !m_pObj ) return;
            irr::core::vector3df rot, dif = m_pObj->getPosition() - v.v;
            rot.Y = atan2( dif.X, dif.Z ) * 180.f / irr::core::PI;
            rot.X = -atan2( dif.Y, sqrt( dif.X * dif.X + dif.Z * dif.Z ) ) * 180.f / irr::core::PI;
            m_pObj->setRotation( rot );
         }

[/code]

[bitplane]

nice to see a useful first post!
welcome to the forums, and thanks

[bob]

nice to see a useful first post!

Thanks, but don't think I'm not full of stupid questions.

[i2k]

Fase target Move

------------------------------------------------------------------------------------
float DTR=(180.0f/3.14159265358979323f);

void faceTargetMove(scene::ISceneNode *obj,float _Speed_)
{
core::vector3df a=obj->getRotation();
core::vector3df p=obj->getPosition();
obj->setPosition(vector3df(p.X+sin(a.Y/DTR)*_Speed_, p.Y, p.Z+cos(a.Y/DTR)*_Speed_));
}
------------------------------------------------------------------------------------

[bob]

Along this same line of confusion

Code: Select all

        void convertAngleToNormalXY( const irr::core::vector3df &a, irr::core::vector3df &n )
        {
            irr::core::matrix4 m;
            m.setRotationDegrees( a );

            n.X = n.Y = 0; n.Z = -1;
            m.transformVect( n );
        }

        void convertNormalToAngleXY( const irr::core::vector3df &n, irr::core::vector3df &a )
        {   a.Y = atan2( n.X, n.Z ) * 180.f / irr::core::PI;
            a.X = -atan2( n.Y, sqrt( n.X * n.X + n.Z * n.Z ) ) * 180.f / irr::core::PI;
            a.Z = 0;
        }