selectedObject.x += delta.X * speed/(float)gameTime.ElapsedGameTime.TotalMilliseconds;
//update gizmo position
Gizmo3D.Position = selectedObject.Position;
Quote:Original post by Buckeye
The action you need to take varies with the type of manipulator.
Warning: Math required!
There are more refined ways to do this, but this will either work for you or give you a start.
For example, for the manipulators that work in a single direction (e.g., the X-axis arrow that allow movement only along 1 axis):
1. Unproject the mouse position where it "picks" the arrow (on WM_LBUTTONDOWN probably). Save as WP (world position) and as MP1 (first mouse position). Calculate D = distance from eye to WP. You have to "pick" the arrow so WP, MP1 and D can be used to start the sequence.
2. When the mouse moves, unproject the new mouse pos to get the 3D direction vector. Set MP2 at the position along the mouse direction vector a distance D from the eye. This is actually a spherical movement of the point but for small movements of a few pixels it's fine.
3. MP2-MP1 is the mouse's 3D movement at a distance D from the eye. The component of MP2-MP1 along the X-axis is the distance and direction to move the object and the manipulators. This makes the object appear to move along the x-axis the same distance along the x-axis that the mouse has "moved."
4. Update WP += x-dist-direction. Recalculate D for the new WP. Set MP1 = position along the mouse direction vector the new distance D from the eye.
5. Wait for another mouse move or WM_LBUTTONUP.
Rotation manipulators are done similarly, intersecting the mouse direction vector with the plane containing the "picked" manipulator, but using the change in angle with respect to the origin of the rotation from one mouse move to the next.
Confused yet? [WINK]
