public final void setRadius(float radius) {
        if (radius < 0) {
            throw new IllegalArgumentException("Light radius cannot be negative");
        }
        
        if (radius == Float.POSITIVE_INFINITY) {
            radius = Float.MAX_VALUE;
        }
        
        this.radius = radius;
        if (radius != 0f) {
            this.invRadius = 1f / radius;
        } else {
            this.invRadius = 0;
        }
    }
Set the radius of the light influence.
<p>
Setting a non-zero radius indicates the light should use attenuation.
If a pixel's distance to this light's position
is greater than the light's radius, then the pixel will not be
affected by this light, if the distance is less than the radius, then
the magnitude of the influence is equal to distance / radius.

@param radius the radius of the light influence.

@throws IllegalArgumentException If radius is negative
jme3-core/src/main/java/com/jme3/light/PointLight.java