1 | cutOffAngle field specifies the spread angle of a cone of illumination whose tip is at the spotlight's location and whose cone axis is aligned parallel with the spotlight's aim direction. Increasing the cutOffAngle field's value widens the spread of the cone, while decreasing the angle narrows the cone of illumination. |
2 | beamWidth field specifies an inner solid angle in which the light source emits light at uniform full intensity. If beamWidth > cutOffAngle, then beamWidth is assumed to be equal to cutOffAngle and the light source emits full intensity within the entire solid angle defined by cutOffAngle. |
3 | Both beamWidth and cutOffAngle must be greater than 0.0 and less than or equal to PI/2 radians. |