colorful noise in cloudy plastic material

[fa2020]

Hi guys,
I have a problem in cloudy material. I set the setting like what you see in the image below but there are lots of colorful noise (dots) all over the sculpture. I tried to change the sample amount to something like 100 but nothing changed. Please help me.
Thanks.

[DMerz III]

For something like cloudy plastic, 100 samples isn't really enough. There are some parameters you can play with to clean it up with less samples, but the easier thing would be to allow more samples, it is one of those calculation heavy materials.

Can you give us an idea of what your lighting settings are? Ray Bounces...Global Illumination...etc. etc.

[fa2020]

Thank you for the response.
I just hit the button "Interior Mode" and didn't change any parameter. I used "maximum time" render method and samples of 100 in the material sample slot. In cloudy plastic we have an advanced parameter that is called "samples". The default amount is 32 but I changed it to 100 but nothing happened. I don't know what to do. Can you please help me? My RAM is 16GB and the CPU is Core i7 4790k 4.0GHZ.
How much time would it take considering my system speed to render a clean image of that cloudy plastic?
What setting should I use to remove those colorful dots?

[Will Gibbons]

The time it takes will depend on the resolution of the image. For cloudy plastic with advanced render mode, you may need more than 1000 samples...

[DriesV]

The colored noise you are seeing is due to the high saturation of the Transmission and/or Cloudiness colors.
Try bringing down the saturation and you should see much less noise. I usually try not to go above a saturation of 30% (HSV color mode).

Dries

[fa2020]

Thank you for the response.
I tried to change the material settings and achieved this result by 600 samples in about 12 min. But I relatively confused that what those two sample slots represent. I marked them in the following image. When do we need to change the sample amount in the cloudy plastic material setting and when do we need to change just sample amount in the render setting?

[DriesV]

Excellent question. The answer is not entirely trivial.

A best practice is to increase material samples, for the materials that need it, first and then increase the samples in Render Options.
The render samples sort of work like a multiplier for the material samples.
The material samples only affect the individual material. The render samples affect the entire scene.

Materials that typically benefit from increased material samples:

• Glossy (rough) metals
• Glossy glass
• Cloudy Plastic

Dries

[DriesV]

As for Cloudy Plastic specifically, then this material generally requires more samples than other materials to look clean. It does depend a lot on the material settings though. More opaque looking cloudy plastics need more samples.

Dries