Missing Lights

I am using IRender 4.0 (full version) with Sketchup. I have created a home model with MANY lights (more than 100), most of them spot lights. When rendering, some of these lights are simply ignored. What can I do?

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Permalink Reply by Render Plus on December 10, 2011 at 7:03am

Do they start to appear you let it render for a few passes?

There is that setting for lights per pass:

Note: setting lights per pass to 100% will make all the lights appear in the first pass, but will slow down each pass because all lights have to be processed. We recommend setting it to 33%, and allowing enough passes to let the rending "cook" and get better and better.

A model with 100s of lights is going to require quite a few passes to get a good result.

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Permalink Reply by Render Plus on December 10, 2011 at 7:04am

Well I’m experimenting with the number of passes now.

The # of lights per pass is set at 20%, minimum 10, but after 6 passes there are a lot of lights still missing. It _appears_ right now that the missing lights are showing up at pass 20 or so. Any explanation?

As each light is added to the model, in a pass - in your example with lights per pass set at 20%, some lights are first added in pass 5, only the direct effect of the light is added the first time. The indirect effects - light bouncing off of the first surface - are added in subsequent passes - so it can take 10 passes for the light itself and the first bounce to appear.

Also, the softness of lights and shadows is accomplished by sampling more points from each light over more passes. The result is that 20 passes is necessary to start seeing things, and hundreds, or more, passes will be required to get a good result. The results just keep improving on each pass.

If a particular light never seems to have an effect, then we would need to look to see if there is something different about it. Perhaps it was too dim, compared to the sun, sky, or other lights, to have a direct effect.