Mass lighting - a speed suggestion (Vlado, please read here)

[Micha_cg]

Hallo,

last night I let render an interior scene - a perfumery with many small boxes with lights inside. Since I have add the approx. 30 point lights the rendering was very slow. Today I have done a test and hide the point lights and placed small surfaces with emitter material instead and ... the rendering speed is much higher.

Vlado, could you tell something to the topic about the advnatgaes and disadvantages? Is it better to use light materials instead light for renderings in GI mode? For which GI methods is it recommended to use light materials?

-Micha

Edit: I forget to say, the speed enhancement is with my scene approx. factor 10 (!).

[vlado]

Mass lighting - a speed suggestion (Vlado, please read here)

When you put a light in the scene, V-Ray must always calculate it for each shading point (e.g. a shadow ray must be traced). When adding more lights, this means a whole lot more rays. However, this also means that illumination/shadows from these lights is of high quality, since it is specifically computed.

On the other hand, self-illuminated lights are naturally handled by the GI solutions, whenever a GI ray hits them. They do not require extra rays. However, since they rely on the GI engines to produce the illumination, the results may be splotchy, or the shadows - blurry.

All in all, lights that are important (e.g. sun light, or sky-light through a large window) are best represented by actual lights.

Lights that are not important and affect only a small portion of the scene may be better handled as self-illuminating objects.

Best regards,
Vlado

[Micha_cg]

Mass lighting - a speed suggestion (Vlado, please read here)

Thank you for the infos, Vlado.