spot_falloff_exponent_light.dae may have too small an exponent to matter

StandardDataSets\collada\library_lights\spot\spot_falloff_exponent_light

There is not a "blessed" image for this test. But it uses a `` of 10. In results consistent with OpenGL this produces in a per-pixel shader a perfect or nearly perfect cutoff, that is identical to the other spotlight document's cutoff, which use an exponent of 1.

It's hard to say precisely if there is no difference between 1 or 10 (at this scale?) because OpenGL uses per-vertex blending, which certainly cannot distinguish between 1 and 10.

Setting the exponent to 100 produces a smaller and fuzzier spotlight boundary in the per-pixel shader. OpenGL's light model produces the same size light, but the fuzziness is the same because per-vertex blending produces about the same effect, corona wise.

Start with StandardDataSets\collada\library_lights\spot\spot_falloff_exponent_light and compare it with the other spotlight document mentioned in the issue. Investigate how falloff exponents 1, 10, and 100 render under the relevant lighting paths, noting that no blessed image currently exists. Done should include a clear expected distinction or a documented reason for the chosen test data.

Written by the indexing model from the issue text.