pickRay function
On success, rayNear
and rayFar
are the points where
the screen space pickX
, pickY
intersect with the near and far
planes respectively.
The viewport is specified by (viewportX
, viewportWidth
) and
(viewportY
, viewportHeight
).
cameraMatrix
includes both the projection and view transforms.
Returns false on error, for example, the mouse is not in the viewport.
Implementation
bool pickRay(
Matrix4 cameraMatrix,
num viewportX,
num viewportWidth,
num viewportY,
num viewportHeight,
num pickX,
num pickY,
Vector3 rayNear,
Vector3 rayFar) {
bool r;
r = unproject(cameraMatrix, viewportX, viewportWidth, viewportY,
viewportHeight, pickX, viewportHeight - pickY, 0.0, rayNear);
if (!r) {
return false;
}
return unproject(cameraMatrix, viewportX, viewportWidth, viewportY,
viewportHeight, pickX, viewportHeight - pickY, 1.0, rayFar);
}