This light allows emission from a line in space, with each point along the line having a photometric distribution defined in an industry standard fashion by using a goniometric shader.

The behaviour of the line goniometric shader is almost exclusively determined by the parameter settings of the shader passed in via the "goniometric shader" argument. In fact ALL arguments to this "goniometric shader" are used by the line goniometric shader, their usage being exactly the same as for a standard "goniometric" light. If the shader passed in via this argument is in some way invalid then the line goniometric light defaults to using a point-light-like distribution for each point along its length.

The other parameters of this light have the following meanings:

"primitive" is used to specify the line in space which defines the spacial extent of the light. This must be a primitive of type LI_PROP_PRIM_POLY_LINE and currently must be a straight line. If an invalid or NULL primitive is provided then the shader will not be able to provide any illumination.

"min lod" and "max lod" control the minimum and maximm levels of detail required when decomposing the line goniometric source. These should be LtFloat values between 0.0 and 1.0. They determine the amount of sampling of the light that is to be done for lighting calculation and visibility analysis. If too low then shadow boundaries will not be reproduced correctly and the illumination from the light may not appear uniform along its length when illuminating nearby objects. If the values are too high then rendering times may be excessive.