Looking for a cause of Interactive Rendering slowdown (+Poll)

[system]

@Designerman77

…
You can bet that I will do that. I would also give you the scene.
Until now I could only notice that IR sometimes crashes, if I made a lot of changes in the scene very quickly - like every few seconds a change.

Regarding parsing time, I noticed that some scenes are simply parsing quicker than others.
Tried erasing parts of the scene… until it remained literally almost empty. Still the same long parsing…

In other scenes that are much bigger, parsing is much quicker…
Strange phenomenon that I had noticed also in previous Corona versions.

I´ll continue testing.

Designerman77, if you had some empty scene which parses for a long time, please could you send it to us? This indeed should not happen and we would like to investigate what could be the cause of this issue.

[system]

@Alexandre Besson

Forestpack and railclone (itoo software plugin for 3dsmax) slow down deeply the iR.

Hello Alexandre, thank you very much for your feedback. We are aware of this problem and currently we are still investigating whether it is some fault on our side or if the slowdowns are caused by aforementioned plug-ins. Also if you could provide us some scene which manifests this issue, it would help us a lot.

[system]

@steyin

…

I uploaded the scene in question. Initial parsing time was around 30 seconds, seems it is due to the Rhino geometry, but switching between viewports IR was ok. Every now and again it slows down a little though. Still, hitting render instead of IR parsing was 4-5 seconds.

Steyin, thank you very much for the scene. We are going to have a look at it.

[Bowcat]

@selene

Anyway, if you could send us the scene you used for this comparison, it would really help us a lot, since we don’t have enough “real-world” examples (scenes) where we could reproduce these kind of issues.

I’m uploading the file to dropbox. The file name is 044.zip.

[Bowcat]

@selene

I recommend you to turn it off and try the Interactive Rendering again, hopefully it will be much better now. Please let us know if turning off this feature helps.

I did.
There was no difference.
IR behaves like on the video.

[rowan_manns]

@lupaz

@selene

I recommend you to turn it off and try the Interactive Rendering again, hopefully it will be much better now. Please let us know if turning off this feature helps.

I did.
There was no difference.
IR behaves like on the video.

Hi,

Did you also try with subsampling enabled and disabled to see if this has any effect?

Cheers,

Rowan

[Bowcat]

@rowmanns

@lupaz

@selene

I recommend you to turn it off and try the Interactive Rendering again, hopefully it will be much better now. Please let us know if turning off this feature helps.

I did.
There was no difference.
IR behaves like on the video.

Hi,

Did you also try with subsampling enabled and disabled to see if this has any effect?

Cheers,

Rowan

I didn’t try that. Because with those big pixels it’s very hard to compare.
I dislike that style of IR.

[Bowcat]

@lupaz

@selene

Anyway, if you could send us the scene you used for this comparison, it would really help us a lot, since we don’t have enough “real-world” examples (scenes) where we could reproduce these kind of issues.

I’m uploading the file to dropbox. The file name is 044.zip.

Hi.
Did you guys receive the scene? I was wondering if you got the same outcome.

[maru]

@lupaz

Here’s a video:

I can send you the scene tomorrow, but honestly I believe the issue is scene independent.

https://youtu.be/rkaqInTu9SA

I am not saying that this is not true, and actually in my simple tests I had the same impression, that in older versions IR was (or at least felt) faster, but here is what actually happens in the above video:

Older version: image is rendered…camera is moved…the previous rendering remains in the background and pixels from the new rendering start appearing immediately on top of it…after some time the 1st pass is finished and next passes continue
Newer version: image is rendered…camera is moved…the previous rendering remains in the background, but pixels from the new rendering do not start appearing…after some time the 1st pass is finished and is then placed on top of the previous rendering

So the way it works is simply different in 1.5 and newer versions, and it is hard to compare render/refresh times. Basically, in 1.5 IR creates this fade-in effect, which is not there in newer versions.
This “new image interactively blending on top of the old one” effect definitely adds to the feeling of better speed and responsiveness, and I described it in my internal report id=371632450

[Bowcat]

Yes! Please!:

• Bring back “new image interactively blending on top of the old one”
• Remove the, in my opinion, unnecessary IR subsampling (at least by default)

[romullus]

@lupaz

• Remove the, in my opinion, unnecessary IR subsampling (at least by default)

Personally i find IR subsampling to be very useful and i certainly don’t agree with your opinion. If you don’t like it, then turn it off and save the settings as defaults. Problem solved!

[Bowcat]

@romullus

@lupaz

• Remove the, in my opinion, unnecessary IR subsampling (at least by default)

Personally i find IR subsampling to be very useful and i certainly don’t agree with your opinion. If you don’t like it, then turn it off and save the settings as defaults. Problem solved!

How is it useful to you, out of curiosity?

BTW, I’m not the only one who finds the subsampling annoying.
Quite honestly I don’t know what is the purpose for it, and why it was brought up in the first place.
The only scenario I can see it being somehow useful is with very simple scenes.

[maru]

@lupaz

How is it useful to you, out of curiosity?

It can help with setting up the composition, lighting, etc. It is easier to see the changes immediately, rather than if you move your mouse…wait…and only then observe the changes. Basically, it makes IR more responsive to your actions. See this video:

Corona Renderer 3 New Features

[Bowcat]

The link to the video seems to be broken.

Maru, wouldn’t this “new image interactively blending on top of the old one” does/used to do that anyway?

@maru

It is easier to see the changes immediately

The changes don’t show immediately. You can see big squares of color that hardly tell you much. The composition can be seen on the viewport in real time anyway

[Bowcat]

A quote by Juraj, who I respect a lot.

@Juraj Talcik

Didn’t find sub-sampling to help much since when IR is slow, this will further obfuscate the image in buffer by making it unrecognizable during those 2 seconds freeze. Without sub-sampling, I can at least directly compare changes.

Sometime all those hang-ups in bigger scenes make regular hit/quit rendering a lot faster to facilitate iteration for me.

[maru]

@lupaz

The link to the video seems to be broken.

Maru, wouldn’t this “new image interactively blending on top of the old one” does/used to do that anyway?

@maru

It is easier to see the changes immediately

The changes don’t show immediately. You can see big squares of color that hardly tell you much. The composition can be seen on the viewport in real time anyway

Fixed the link - https://youtu.be/nAx9_EDyxCw

[maru]

@lupaz

A quote by Juraj, who I respect a lot.

@Juraj Talcik

Didn’t find sub-sampling to help much since when IR is slow, this will further obfuscate the image in buffer by making it unrecognizable during those 2 seconds freeze. Without sub-sampling, I can at least directly compare changes.

Sometime all those hang-ups in bigger scenes make regular hit/quit rendering a lot faster to facilitate iteration for me.

Another quote by Juraj from September 27:

the whole IR conundrum is strange. For me, IR was unusable in beginning, in time which people remember oppositely, and it’s very smooth right now, and my scenes (while lacking ForestPack, disclaimer) are often gigantic in terms of unique poly and even more instances.
Right now I have 2 billion poly scene with CoronaScatter, and it’s very smooth, of course, not too helpful since it clears slowly due to having millions of SSS carpet strands in small interior, but still smooth.

OFC I don’t want to start a Juraj-quotes-fight, but just showing that the whole IR issue is relative, and possibly scene and system dependent.

[Bowcat]

Yes, I remember that video.
In my opinion this video is more impressive in regards to IR:

Corona Renderer 1.3 New features and improvements

I really don’t understand what was the need to change it to subsampling.
I don’t expect you to answer this since you can choose to do anything with your software.
It’s just a shame that something that was so good was changed.

I love Corona and the work that you do is just amazing. So please don’t get my criticism and negative, but constructive.

Thanks.

[maru]

@lupaz

I really don’t understand what was the need to change it to subsampling.
I don’t expect you to answer this since you can choose to do anything with your software.
It’s just a shame that something that was so good was changed.

I love Corona and the work that you do is just amazing. So please don’t get my criticism and negative, but constructive.

Thanks.

Of course, we were counting on feedback exactly like this. It will definitely help us make Corona better!

[romullus]

maru, i just want to let you know, that not everyone shares lupaz’s opinion about IR subsampling. Here’s two short videos, that shows how subsampling is extremely useful not only in complex scenes, but in very simple ones as well. Without subsampling, IR is almost completely useless. Please consider this, before making any changes to defaults.

Corona IR subsampling (complex scene)

Corona IR subsampling (simple scene)