How to reduce rendering times when using "IDG Iray Gel Lights and Gobos"

chachah

I do not know if this is really the place to publish this, or even if someone has not already done so. But anyway I think that my trick could help to restore all its interest to a product that deserves it.

I took advantage of the last PC+ annual sales to get some products among which "IDG Iray Gel Lights and Gobos" by DestinysGarden and InaneGlory. At first, like many others probably, I was quite disappointed by the excessively long render times.

For my rendering tests the light is directed towards a matt white vertical plane. The environment mode is set to "Scene Only".

As the first screenshot shows, after 7 minutes the progress bar has not even taken off yet!

This is because the light rays emitted by the 5 light sources bounce against the white walls inside the projector almost indefinitely before eventually exiting through the aperture. To prevent this the solution is really very simple: select the projector > open the "Surface" pane > select "Gel 1" and "Shell" > assign black to the "Base Color" parameter. The black will absorb the rays thus ending their race, and computation times will be considerably reduced as shown in the screenshot 3

DestinysGarden and InaneGlory could publish a patch to their product to correct the inconvenience, and give it a second youth at the same time. Thanks to them.

fastbike1

You can also limit the number of light bounces. The default setting allows infinite bounces. A value between 7 and 10 will not compormise render quality but will provide faster renders.

chachah

That is true.

chachah

fastbike1 said:

You can also limit the number of light bounces. The default setting allows infinite bounces. A value between 7 and 10 will not compormise render quality but will provide faster renders.

That is true. Your suggestion is relevant. However the method I propose completely eliminates unnecessary bounces without altering those that contribute to the image's realism. But we can also do both, we would gain even more speed, which is very significant when doing animation.