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View Full Version : position lights to "catch" the "carpaintgloss"


the_jonas
11-14-2002, 10:44 AM
Anyone here who can give me some tips of to position my lights to "catch" the glossiveness of the carsurface?. i dont wanna render with radiosity. i use lightwave. i have a hdri image applied. but i dont get that fancy look. i want to "catch the lines in the carbodymodel" better by placing lights right. well excuse my bad english, but i think most of u know what i'm talking about. i use BRDF shader also. no imagefilters.

Ian Jones
11-14-2002, 11:17 AM
In 3dsmax 4 you can use the 'place highlight' tool. It literally positions the light so that the highlight appears where you want it to. If you want to do it manually you need to understand how a ray of light travels, bounces or reflects.

If I had a flat reflective surface and I used a laser pointer and angled it into the flat surface at 45 degrees, then it would bounce up at 45 degrees to the flat surface in the opposite direction. The angle of incidence is the same on reflection. That is of course ignoring any more complex surfaces with refraction etc...

So if you want to place a light to shine a highlight into the camera manually you need to imagine the ray of light in your minds eye, and plot its course and reflection off the surface of your car and into the camera. A better way to do so though, would be to trace backwards. By imagining the light going from the camera to the point on your object where you want the highlight, then imaging the angle at which that ray of light would bounce and place your light source along that line. It would be tricky, but you can always use trial and error to get it just right. Put the light very close to your object to start with, then move it further away. This should help you get the approximate position faster than placing your light miles away and geussing more.

Hope that helps.

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