Property Value

Type: Boolean
if the billboard axis vector is the fixed axis and the normal vector is adjusted; otherwise, if the normal vector is fixed and the axis vector is adjusted.

To orient a billboard two vectors, the axis vector and the normal vector, are required. If these two vectors are not perpendicular, then one vector is kept constant and the second vector is made orthonormal to the first vector. For most particle effects, the normal should be the fixed axis (e.g. for fire, smoke). For billboards with a fixed direction in world space (e.g. for tree billboards or laser beams), the axis vector should be the fixed vector.