I’m about to set up a room only illuminated with candles. The candles are not really closeup and the rendering will not be animated. What is the best way to go about?
Should the candle flame be an emission shader or do I place a light source inside the flame? What would be the best type of light source? What effect is to be expected with multiple lightsources on complex materials like wax (SSS) and glass? Are there any tricks that I might get away with?
This is what I got so far:
The light thrown onto the scene from the candles looks right to me. However I think the flames themselves are way to bright. How can I reduce that without affecting the overall lighting? The candle light are two area lights one pointing up and the other down each with a strength of 50.
And there is the issue with the fireflies. This is rendered with 2000 samples and no caustics. The final render will have 10000 samples. Any good way to get rid of them in the rendering (I know I can do it when compositing).
It kinda depends on the effect you are going for. A film or portrait set that is supposed to be “candle lit” won’t truly be candle lit. The candles just provide ambience, some big warm stage lights do the real lighting. You could go for a setup like that, and just have a light diffuse shader on the candles. If you want lights coming from the candles, try making a small cylinder around the flame, give it the powerful emission shader, but under “ray visibility” (object properties), disable everything except “diffuse”. Then on your flame mesh, give it a weaker emission shader and on its ray visibility settings, uncheck “diffuse”. And also disable “multiple importance sample” on the flame emitter mat. This way, you have the bright light supplied by an invisible easily sampled lamp, while the visible flame appears to do the lighting.
This should also fix a good chunk of the fireflies. You might still have some from the candle itself though. You can try disabling diffuse ray visibility on the camera objects. That will prevent it from casting global illumination, which is probably where a lot of the fireflies are coming from.
Thanks. Based on your suggestion I got this:
So the final result should be somewhere in between.
Does the size of the object that emits the light matter?
