Pan and zoom

[Maelvon]

Hello,

I see in the examples that we can rotate the camera (yaw and pitch)
around an object. But I don't see example of panning and zooming. Is
that possible?

I see some threads here but nothing very clear.

Thanks,

Maelvon

[Lindsay Kay]

Hi Maelvon, 

sure is, you can do this by manipulating the 'eye' and 'look' properties of the camera node.

To pan, just find the vertical and horizontal vectors orthogonal to the eye->look and eye->up vectors and move the eye and look points along those.

Some pseudocode to get you started:

pan(x, y, rate) {

        // get look and eye from your camera node

        var forward = normalizeVec3(subVec3([look.x, look.y, look.z], [eye.x, eye.y, eye.z]));

        var axis = cross3Vec3(up, forward);

        up = normalizeVec3(cross3Vec3(axis, forward));

        var right = normalizeVec3(cross3Vec3(forward, up));

        var moveX = mulVec3Scalar(right, x * rate);

        var moveY = mulVec3Scalar(up, -y * rate);

        var move = addVec3(moveX, moveY);

        var newLook = addVec3([look.x, look.y, look.z], move);

        var newEye = addVec3([eye.x, eye.y, eye.z], move);

        var look2 = { x: newLook[0], y: newLook[1], z: newLook[2] };

        var eye2 = { x: newEye[0], y: newEye[1], z: newEye[2] };

       // ... now set new look2 and eye2 on camera node