Therese <[EMAIL PROTECTED]> wrote: > I've run into some trouble that concerns spotlights and large lowpoly > objects. It appears as when I animate a spotlight over the low poly > object the light just flickers as it crosses the polygons, and > sometimes it isn't visible at all.
Hi Therese, A spotlight will only light a face if the light falls on all three vertices of that face. A low-polygon object is likely to have faces which are large compared to the diameter of the cone of the spot-light at the point where it meets the object. If all three vertices are lit, but the spotlight is too close to the face, the face will only be dimly lit. To obtain a highlight effect with a spotlight, you need to use small faces (which implies a high polygon count), and a relatively distant spotlight. I have built a 72 K movie that shows the effect of a spotlight on a plane. It allows you to vary the spotAngle, the distance of the spotlight from the plane and the number of faces used to create the plane. You can use this to judge how many polygons you will need in a given area to achieve the effect that you are hoping for. The movie clearly demonstrates the cut-off point where faces at the corners of the plane will receive no light. It also outputs a graph that shows that the cut-off point can be determined as a function of tan(spotAngle) * distance. If anyone would like a copy of the movie, please let me know. Cheers, James [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
