Direct light Diffuse mode VS Path Tracing

[Dave_Yu]

both seems to give similar results on some simple scenes. What is the benefits and differences between direct light diffuse mode and path tracing. Path tracing seems to give more fireflies in my scenes.

[FooZe]

One of the differences is the lack of caustics in the DL kernel.
It could be that some of the fireflies you are seeing with the PT kernel are actually caustics that need more time to resolve and become noise free.
You can confirm/deny this by playing with the caustic blur setting. If the fireflies decrease when you put the caustic blur to 1.0, this confirms they are what you are seeing. (this will blur the caustics so much that they are basically washed out).

Also, PMC is far better at spending time on the caustics to clean them up quicker.

Thanks
Chris.

[Dave_Yu]

Thanks! I'll try that. PMC is good for stills. Haven't tried it for animation yet

[Olitech]

Oh man! I had this in reverse...

I keep setting caustic blur to low values (01. - 0.3, etc) thinking I was blurring caustics. And wondering why they would increase. Subsequently having to turn samples waaaaay up; increasing rendering times; and so on.

Now I know why I've been having such a hard time reducing the noise. Doh!

So value of 1 is the highest caustic blur setting?

best,
O

[Karba]

So value of 1 is the highest caustic blur setting?

Yes