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Directional Lights - Casting Shadows

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Hi, I''ve been working on a terrain engine in D3D8, and have decided to pre-process my lighting in the form of lightmaps... all funky looking so far, real nice However, when it comes to Directional lights, I have a slight problem... When casting a shadow I construct a line from the light to the point in question, trace along it, comparing against bounding boxes, then doing a line-plane-barycentric test at a higher resolution. With a directional light there is no origin for the light, such that you can strictly define a line to trace for shadows... My current solution is to take the center point of the terrain, then calculate a vector at the specified angle (for the directional light), and then multiply it such that the "starting" point for the directional light is almost infinitely far away (or as far as the datatype allows), such that the angles between the the min/max points will be so small as to not really matter... that way the shadows aren''t entirely accurate, yet they''re a pretty good approximation... Is this a good way of solving the problem? or is there a clever/better way of doing this that i haven''t thought of?? Many thanks for any help.. Jack;

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