billboard derived from ygNode | Example | Source | Header |
Messages |
mode | (point | axis), three floats | set the mode and optional axis |
Comments |
constructor billboard
method reset
1 set the rotation mode to axial with Z axis (0,0,1)
method message
1 set the mode and optional axis
method app
1 find viewer in the world
2 if a viewer is found
2.1 get viewer position vector relative to this node
2.2 get the cross product of the viewer vector and the rotation axis
2.3 establish the object front as the positive Y-axis
2.4 get the cross product of the front axis and the rotation axis
2.5 get a normal towards the viewer by crossing this cross with the rotation axis
2.6 get the rotation to the viewer vector
2.7 create a matrix with this rotation
2.8 if the mode if point then
2.8.1 get the rotation about the viewer cross product2.9 set the dcs matrix
2.8.2 set the final matrix to this rotation
2.8.3 add this rotation matrix to the existing rotation matrix