"Show samples" color meanings

[mts]

Hello,
although this seems to be a basic question I did not find a clear answer to it, so I am posting it here:

When checking the "show samples" checkbox in the Image sampler settings, what do the resulting colors mean?

I assume green means low samples, red means medium and blue means high sample count (all related to the min - max subdivs settings)? And a bright blue means even more samples than a dark blue???
As I am getting some confusing results in my rendertests I would like to know for sure so if anybody knows please tell me.

And secondly, just to be sure: only the image samples are shown here, that is to say only the "eye rays", right? Material samples are not taken into account, are they?

Thanks!

[Marti]

Basically the colors are blue-green-red gradient . Blue color represents the pixels where the image sampler takes minimum subdivisions. Green shows the middle value and red shows the pixels for which the maximum number of subdivisions is taken. For instance if you set the max subdivs to 20 but and the image shows mostly blue samples this means that in these areas only (for example) 4-5 samples per pixel are taken and the maximum subdivs rate is not reached. This means that in order to increase the quality of the render the threshold is too high and has to be decreased.
Sample Rate RE could be also used.
The image shows only the samples taken from the image sampler and is not affected by the Material samples.

[joconnell]

Marta this might be a bit of a dumb idea or possibly a performance overhead, but would it be possible to change it to using one channel per type of sample? As in dedicate the 256 colours of the red channel to only image sampling, the green channel to material sampling and the blue channel to something else?

[vlado]

V-Ray only counts the image samples for the moment; it would be an additional overhead to keep track of material samples separately.

Best regards,
Vlado

[joconnell]

Cheers Vlado. Do we pretty much assume then that all other sample amounts are being driven by the amount of samples the image sampler assigns? As in does the image sampler make the final decision with regard to how many samples a material will use so we can use the sample rate element as a good guess as to how to tweak for noise / speed?

[vlado]

Well, it is not exactly the same thing, but it can be used as a rough guide.

Best regards,
Vlado