what is the difference between progressive and non progresive?

[Inbal]

Hi,
Im using sketchup 17 with vray 3 and I am trying to understand what is the real difference between marking the progressive vs not marking it?
I would like a full explanation why to use the interactive option at all- as for my understanding it is the new real time render
but when you go to progressive mode is it also real time and shows you the scene changes as you go along, you just have better control over the result quality wise...

a full explanation will be very helpful, thank you!

[Inbal]

[Peter.Chaushev]

Hello, Inbal,

Let me start by directing you to https://docs.chaosgroup.com/display/...ortheSituation

"No one image sampler is best for all scenes or workflows. Choosing the best image sampler is usually a matter of experimentation, but there are a few guidelines you can follow.

• Setting Image Sampler Type to Bucket is the same as the Adaptive Type in previous versions of V-Ray.
• With the Bucket type, disabling Max. Subdivs will also disable the Noise threshold and will match the Fixed sample behavior in earlier versions of V-Ray.
• Progressive is useful when it is necessary to see overall results quickly (like when placing light, building shaders, or general Look Development work) because it generates the whole image at once and progressively cleans up the noise in it. Additionally, the render can be stopped at any time before resolving completely.
• Progressive is also helpful when a set amount of time to spend per render is needed. This can also be useful when rendering test animations, where the entire sequence must be rendered within a certain time frame.
• Combining the VRayDenoiser with Progressive renders can help with cleaning up render noise. If the Denoiser's Update button is used when manually cancelling a render, the noise levels will be adequate enough to use the denoiser to avoid splotches and/or other unwanted effects. Also note that in 3ds max 2017, there is a Stop button in addition to the Cancel button in the progress window. After clicking Stop, V-Ray will begin denoising the render.
• Using Bucket when running Distributed Renders can be helpful for cutting down on network traffic and reducing the loss of information if work is not completed by one or more DR machines."

Regarding Interactive rendering - it is pretty much self-explanatory. Its main use is to interactively render the whole scene or only a selected region of it while making changes to materials, settings or the scene geometry. This accommodates swifter workflow and encourages users to experiment more when working with V-Ray.

Let me know if you have any further questions!

Kind regards,
Peter Chaushev

[Inbal]

Hi Peter,
thanks for the elaborate response,
I'm affraid Im still puzzled and have more questions:

1. In what case would I want to use the bucket mode instead of the progressive?
you wrote -
"Setting Image Sampler Type to Bucket is the same as the Adaptive Type in previous versions of V-Ray.
With the Bucket type, disabling Max. Subdivs will also disable the Noise threshold and will match the Fixed sample behavior in earlier versions of V-Ray."

I dont think I ever used the fixed sample, when would I want to do that?
and if the bucket is the same is the adaptive, is the progressive the same as dmc?


can you alaborate more on when to use either of them?

2. you wrote "Progressive is useful when it is necessary to see overall results quickly "
but isn't the Interactive rendering meant for that exact reason?
when I render, will the result be different in the interactive vs the Progressive if I'll wait for it to finish?

3. You wrote the progressive is good for test animations and later you refer to 3ds MAX... I'm using Sketchup, were you talking about animations in 3ds MAX or were you talking about rendering separate images to create a movie?

4. "Combining the VRayDenoiser with Progressive renders can help with cleaning up render noise."
but you can also use the Denoiser in the interactive and in the bucket mode.. so how come it is an advantage?
and on that note- should I always use the Denoiser?

5."Using Bucket when running Distributed Renders can be helpful for cutting down on network traffic and reducing the loss of information if work is not completed by one or more DR machines."
does it mean I always want to use the bucket when using the swarm option?

thanks so much for all the info, it really is helpful!
Inbal

[Peter.Chaushev]

1. In what case would I want to use the bucket mode instead of the progressive?
you wrote -
"Setting Image Sampler Type to Bucket is the same as the Adaptive Type in previous versions of V-Ray.
With the Bucket type, disabling Max. Subdivs will also disable the Noise threshold and will match the Fixed sample behavior in earlier versions of V-Ray."

I dont think I ever used the fixed sample, when would I want to do that?

Actually this is not relevant for V-Ray 3.4 for SketchUp as Max subdivs can't be turned off, and the general workflow is to simply use the quality presets instead of manually adjusting the min and max subdiv parameters. You can still set min and max subdivs to the same amount to simulate Fixed sampling behavior, however, there is currently no benefit in using Fixed except for debugging.
When it comes to Bucket rendering, the main benefit it has over Progressive is lower memory usage (depending on the scene).

2. you wrote "Progressive is useful when it is necessary to see overall results quickly "
but isn't the Interactive rendering meant for that exact reason?
when I render, will the result be different in the interactive vs the Progressive if I'll wait for it to finish?

Interactive and non-Interactive Progressive rendering both produce the same results when they reach the set noise/time threshold. However, Interactive never really stops, instead it remains in standby awaiting for further changes to the scene unless manually interrupted (the VFB "Stop" button). This means it will use resources, license, and also not trigger actions such as saving the output to a file automatically upon finishing or denoising upon reaching a threshold.

3. You wrote the progressive is good for test animations and later you refer to 3ds MAX... I'm using Sketchup, were you talking about animations in 3ds MAX or were you talking about rendering separate images to create a movie?

The time limit when using Progressive sampler guarantees you will see the whole frame rendered and only the quality will vary depending on the time length which has been set. Time limit is not an option when rendering in Buckets as it means only parts of the frame would be rendered if the time set is insufficient and this is considered an undesirable workflow.

4. "Combining the VRayDenoiser with Progressive renders can help with cleaning up render noise."
but you can also use the Denoiser in the interactive and in the bucket mode.. so how come it is an advantage?
and on that note- should I always use the Denoiser?

Denoiser is currently not available in Interactive rendering mode.
Using Denoiser depends on each scene. It is recommended to experiment with your workflow in different projects for determining what would the best case for each one be.

5."Using Bucket when running Distributed Renders can be helpful for cutting down on network traffic and reducing the loss of information if work is not completed by one or more DR machines."
does it mean I always want to use the bucket when using the swarm option?

It has its advantage, but the decision whether to use Bucket or Progressive sampling depends on multiple factors (some already mentioned above) and not simply whether you are rendering on one machine or multiple.


Kind regards,
Peter Chaushev

[Inbal]

Thank you!