IR used to be interactive

[fraine7]

Since I fully switched over to Corona around 18 months ago I’ve always relied heavily on the Interactive Renderer to fine-tune materials/lighting etc etc. I’ve even used it ‘live’ in client meetings to get real-time feedback and critique. It was flawless around 1 year ago, probably around version 1.4 if I had to guess.

I’m not sure when it stopped working fluidly but IR is now becoming useless for anything but the simplest of scenes. I have plenty of RAM to handle the scale and complexity of my interiors but I find myself waiting constantly for updates and restarts when performing the simplest of changes to my scenes. Often I have to zoom in/out to keep IR ticking over, otherwise it just fails to interactively update.

I haven’t gone as far as submitting bug reports just yet but I was curious to know if any other users have noticed IR becoming slower and less interactive recently?

(Corona Camera or Camera Mod always used as I know there are issues with Physical Cam)

[maru]

If anything, it should be more responsive than before.
Could you record your screen when IR is working slowly?

[Giona]

Sometimes I have the same issue, I tried to solve forcing the IR to use only Path Tracing, but for interiors scene is not the best option, and it doesn't fix the issue completely.
I really hope this can be solved in the near future!

[fraine7]

Maru - I thought exactly the same, I have more RAM than ever, better hardware all round in fact. Add to that all of the optimisation that you guys have carried out and it should mean that interactive rendering is quicker or at least more responsive than older versions.

giona4 - I've also tried the force Path Tracing option but as you say this isn't very good for cleaning up interiors.

I will capture an interactive session as soon as I can and post the link here.

[Ludvik Koutny]

There were quite a few IR performance regressions ever since 1.4, so they probably just added up. I've reported some of them, but they are still backlogged on mantis somewhere.

[Bormax]

Hi
Do you guys use proxies and animation in your scenes? I mean even if you render static pictures, but you change for some reason frame number to render?

[fraine7]

Hi Bormax, sometimes I will keyframe scene changes but not always. Have you found this to be a cause of IR sluggishness?

Rawalanche - Regressions definitely sounds like an adequate description. It actually reminds me of VrayRT, I never really know what it’s doing anymore or why it needs to completely restart if I change a light’s intensity or tweak a colour in the mat editor.

I tend to use the zoom functionality quite heavily, both max’s 2D pan/zoom and frame buffer zooming to focus sampling on a specific area. This often messes up my IR sessions once I’m back at 1:1 (zoomed out). This isn’t the only cause but it’s one I encounter everyday.

[Bormax]

Hi Bormax, sometimes I will keyframe scene changes but not always. Have you found this to be a cause of IR sluggishness?

Yes fraine7. Actually it makes problem not only for IR, this issue slows down parsing scene process and as a result IR starts to be not responsive especially in scenes with big amount of proxies, at least it's still true for my computer with dual Xeons. I posted about it here, check this link
https://forum.corona-renderer.com/index.php?topic=14716.msg94525#msg94525

That was the reason why I didn't use IR even for quite simple exterior scenes with normal amount of greenery, and always thought - what is the problem with my computer (it's not the slowest one :))?, and why in tutorial videos IR works fast for much more complex scenes with no problem?
Since the moment I get the point and exclude animation from my scenes I use IR constantly

[fraine7]

Thanks Bormax, having read your own thread in the link it seems we work in a similar way. Animating the sun position or some other object/light/material etc. I don’t use proxies much so I don’t think they are to blame but IR is clearly affected by key frames being present.

I have been reading through some of the other IR related posts and I am convinced that something was broken in an earlier version of Corona which has gone under the radar, getting progressively worse as the software evolves and new versions are released. As Rawalanche suggested with the compounded regressions.

[dj_buckley]

I second this - whenever I make a change it seems to restart, as though I've just opened the IR window again.

[fraine7]

Kind of glad to know I’m not the only one experiencing these issues as it means we have more chance of getting the developers to look into possible causes.

[LUKEC3D]

For me is the same, after 1.4 IR is very less interactive, sure i work with heavy scene, but with 1.4 when i change one material, or one light outside light mix, response was immediatly, now is very slow, sometime freeze for a 5 - 10 seconds, and then start, every time, restart from 0, with " big pixels" and i need wait a lot until i can see my fixes. I've a lot of different comp, from I7 12 4930 K until xeon 2680 v4, all ssd 64 gb of ram and windows 7 and windows 10, i i've a scene with few thousand poly until hundred millions of polyg, i use scene standard, scene with proxys, scene with displacement, scene with easy shaders scene wirh complex shaders, scene with xref and so on... scene start from 0 with corona 1.5, 1.6 and now 1.7, old scene ... and i've 4 guys work in different mode ...
Corona render was perfect because it's simple, fast, effective, and instant .. now it's getting more complicated with many features, I do not want it to eventually become like other slow and difficult to use engines. Immediate speed and ease of use are the elements to be pursued, photographic rendering and the end we must achieve. Who wants a complicated, slow and difficult to use software knows where to look ... I think it is better not to distort Corona Render.
I also have to say that crown 1.7 has much less freeze than crown 1.6, it seems more stable.
I think it is useless to continue running behind a rabbit to try to overtake it and have the short breath .. better to walk slowly and stay fit.

[TomG]

If you want to change the "big pixels first" (which is subsampling to give you a faster overview of the scene while waiting to show more detail), then that can be adjusted in the Devel / Debug section, smaller numbers give less subsampling (smaller "big pixels") and vice versa:

[PROH]

Yes. My preferred setting for Subsampling is 1 or 0 (off). But still IR feels slower - especially the very first use after loading a scene (just like regular render).

[Christa Noel]

now IR run faster than 1.4 for me and without subsampling IR will gives less interactive feel. so I think there is no any benefit in disabling the IR subsampling.
and imho the lag at the very first IR is acknowledged, IIRC there is a thread said that it is caused by the transition from 64x64 output size to our setting and why there is 64x64px output size, because of the need of pre-render minimum RAM usage..

[fraine7]

Subsampling only takes place once IR is up and running, this doesn't explain why IR needs to completely restart when a light intensity or material colour is changed slightly.

It's not so much that IR rendering/cleanup is slower (this would be where subsampling comes into the discussion) - the real issue is the sluggishness of updates/feedback in general.

Recently I have found that rendering a draft image is quicker than waiting for feedback using IR, this is a huge backward step and is something I used to have to do in Vray as VrayRT just wasn't fit for purpose.

[romullus]

this doesn't explain why IR needs to completely restart when a light intensity or material colour is changed slightly.

Huh? So you want that IR would hapilly render without even noticing that user changed material's colour from red to green? It needs to restart to reflect changes made in the scene. Of course it would be great if IR wouldn't restart just from navigating in material editor or selecting objects or anything that does not change output appearence, but i believe that in 9 cases out of 10, it's more 3ds max's fault rarther than Corona's.

[3dboomerang]

+1 here, whenever a change is made in the material shaders, or HDRI, sun, etc.. it's as if the whole scene is reloading, huge lagg - then finaly, it updates - sometimes suddenly after being stuck for 2 minutes the vfb reloads and did a number of passes - stressing me out: waste of time to use corona-IR in this state

using proxies makes everything much worse, same for forest pack pro objects etc

always reloading...

IR is usable for small scenes, terrible for larger or heavier archviz scenes

ALSO: whenever browsing in material shaders for some reason also refreshes the IR - very annoying since I didn't make a change :-/

[fraine7]

this doesn't explain why IR needs to completely restart when a light intensity or material colour is changed slightly.

Huh? So you want that IR would hapilly render without even noticing that user changed material's colour from red to green? It needs to restart to reflect changes made in the scene. Of course it would be great if IR wouldn't restart just from navigating in material editor or selecting objects or anything that does not change output appearence, but i believe that in 9 cases out of 10, it's more 3ds max's fault rarther than Corona's.

I get that it would need to restart to some extent, but is it not caching or storing some data in order to speed things up, thus making it interactive? There is nothing interactive about changing a wall colour from mid to light blue and then waiting 60 seconds to see the effect.

My main concern is that it used to be much quicker to get feedback from Corona IR, I have no idea what has changed, all I know is that it isn't what it used to be.

3dBoomerang - You've hit the nail on the head, 'always reloading' even when it has no reason to

[TomG]

As a note, I wasn't suggesting that disabling or changing subsampling will speed things up :) In fact, it will mean a longer wait to see the preview (this is why subsampling is introduced, so you get a faster, rough overview of the scene) - I just mentioned it as someone said they didn't like the "big pixels", to make sure they were aware they could adjust this. But it has no bearing on the other speed / performance questions from folks.

[dj_buckley]

this doesn't explain why IR needs to completely restart when a light intensity or material colour is changed slightly.

Huh? So you want that IR would hapilly render without even noticing that user changed material's colour from red to green? It needs to restart to reflect changes made in the scene. Of course it would be great if IR wouldn't restart just from navigating in material editor or selecting objects or anything that does not change output appearence, but i believe that in 9 cases out of 10, it's more 3ds max's fault rarther than Corona's.

I get that it would need to restart to some extent, but is it not caching or storing some data in order to speed things up, thus making it interactive? There is nothing interactive about changing a wall colour from mid to light blue and then waiting 60 seconds to see the effect.

My main concern is that it used to be much quicker to get feedback from Corona IR, I have no idea what has changed, all I know is that it isn't what it used to be.

3dBoomerang - You've hit the nail on the head, 'always reloading' even when it has no reason to

For me, on larger more complex scenes, it's almost quicker to just hit render look at the first few passes rather than deal with the freezing/lockups that IR gives me

[fraine7]

this doesn't explain why IR needs to completely restart when a light intensity or material colour is changed slightly.

Huh? So you want that IR would hapilly render without even noticing that user changed material's colour from red to green? It needs to restart to reflect changes made in the scene. Of course it would be great if IR wouldn't restart just from navigating in material editor or selecting objects or anything that does not change output appearence, but i believe that in 9 cases out of 10, it's more 3ds max's fault rarther than Corona's.

I get that it would need to restart to some extent, but is it not caching or storing some data in order to speed things up, thus making it interactive? There is nothing interactive about changing a wall colour from mid to light blue and then waiting 60 seconds to see the effect.

My main concern is that it used to be much quicker to get feedback from Corona IR, I have no idea what has changed, all I know is that it isn't what it used to be.

3dBoomerang - You've hit the nail on the head, 'always reloading' even when it has no reason to

For me, on larger more complex scenes, it's almost quicker to just hit render look at the first few passes rather than deal with the freezing/lockups that IR gives me

I agree completely Dave, that's what I used to have to do in Vray, feels like a huge backwards step doesn't it?

[Bormax]

Hello again!

I tried to find the problem point for IR in my scenes. Worst case for me is case when I'm changing camera position or lens angle in exterior scenes - it takes really much time for IR to start refreshing picture. I made a lot of test excluding/including different types of objects from rendering. And the thing which I finally found is very simple - once I just switched view from the camera to the perspective everything has changed for me - IR SARTS TO FLY LIKE A BIRD when I turn/change viewpoint position! I tried this in different scenes and everywhere I've got the same result - whatever type of cameras I used (corona, vray, standard) they make IR/MAX to freeze for a while before refreshing starts, in perspective view refreshing starts almost immediately. For example for one of my exterior scenes with quite normal amount of green stuff for my projects (a lot of trees, big areas of grass, forest on background, areas filled with cobblestone (scattered with ForestPack) and cars) time from change-to-picture refreshing was 26 seconds from camera, and 1.5 seconds if I used perspective view!
In my cases problem is FP with active Camera->Limit to visibility ON. If you use camera this function is working and every time you change something concerning camera FP rebuilds all it's objects and it makes Max to freeze. If you use perspective view this function doesn't work.

The reason why I didn't realize that FP is the biggest problem here is that even if FP objects are NOT renderable FP REBUILDS it's objects anyway. They are not visible in viewport while IR is active, but FP still makes rebuilding and it freezes Max. If FP objects are not renderable and hidden from viewport picture starts refresh immediately.

I use layers properties to manage what is renderable what is not for big things such as trees and grass (mostly scattered with FP), but I didn't hide these layers, only made them not renderable and for work with camera position/properties using IR it was critical for IR's feedback. So, for me solution is to hide FP objects if they are not renderable (like grass) when I work with camera and avoid Limit to visibility function of objects which are important for picture composition, but could be switch on automatically when FP object was created (like trees)

I know, it doesn't solve all problems described above, but maybe this information can help to someone who works using the same way as I do

[LUKEC3D]

aaa Now I understand ... it's like putting the sign out of the shops with the script "I'm back now" .. now it's all clear! thank you !

Probably did not understand my comment, I do not need anyone to explain why the interactive preview is slow, I would like it to come back in versions 1.4 and earlier.

Also how do I view that panel where I can modify those parameters, to make IR more immediate and responsive?

Tnks

[ThomasCoote]

+1

I've noticed this ever since the update the allowed interactive to work only for the zoomed in area. I can't recall which update that was, but since then it's been a chore to use.

[bluebox]

Watching all those serious problems people reported on 1.7 dailies we decided to postpone installing 1.7 dailies and official 1.7 release.
At some point we only tried 1.7 Sep 15 build and it was running kinda OK'ish, BUT just a quick comparison between Sep 15 build and official 1.7 release on simple 2mil poly interior scene when changing just the intensity of light sources in IR:
Sep 15 build - immediate feedback
Official 1.7 release - ~15sec choke, then IR restart

Interactive Rendering is no longer interactive guys. I can easily imagine that IR was the key point that drew people towards Corona. This really needs adressing, no matter if it is Max's or Corona's fault there can be no excuses. People can wait for interface tooltips updates etc. but imho core features like IR being interactive again and DR being reliable and stable are most important.

EDIT: simple scene I was reffering to could be created as far as 1.5 back.
On scene open IR is still in immediate response, even when 1.7 is installed.
As soon as I reset render settings IR takes ~15 sec. to give feedback.

[fraine7]

Thanks for adding your own personal experiences everyone, it’s much better for the devs to know that these issues are not isolated cases and that IR is becoming less useable with each release.

Bormax - I completely agree with your remarks about cameras slowing IR right down, perspective navigation feels way more like IR used to a few versions ago.

I will do some testing when I can in the hope of getting enough info to file a bug report on mantis.

LUKEC3D - if you click system settings inside the Corona render settings you should see a checkbox called ‘enable dev tools’ or something along them lines. Checking this will add a new section to your performance tab and in there will be an area for IR subsampling. (Not currently at my PC but I think that’s right)

Bluebox - I am with you on that one, a fluid and responsive IR is the single most important thing in my workflow and any bugs which slow it down should be investigated with the highest priority. I imagine for many it was the main feature which first made them consider switching from Vray - it was the catalyst for me too.

[Monkeybrother]

I'm experiencing the same thing. We have been using 1.5.2 up until now and I notice a big difference in speed (negative) when opening scenes that worked fine-ish in 1.7. The most noticable thing is the choking, IR just stops for a (long) while then restarts whenever something changes.

[fraine7]

*Bump*

Is IR still broken or buggy for everyone else?

Still feels terrible for me, would be a shame to think this is how it will continue to perform moving forward

[romullus]

Can't speak for anybody else, but IR is fine for me, from 1.7.2 through latest daily build.

[maru]

You cannot call me impartial, but I also haven't noticed any slowdown or other issues with IR in 1.7 hf2 or the latest dailies. It seems that some performance issues may be happening on some specific computers only, or with some specific scene setup... We have a few reports about this open (mainly from dual Xeon users), and we are investigating this.

[NicolasC]

We have a few reports about this open (mainly from dual Xeon users), and we are investigating this.

Oh yes, please ;)

[Ondra]

We AFAIK currently do not have any solid performance regression in interactive that we could investigate.
Before you swarm me with answers ;):

• We know there are cases where interactive is slow. For example manipulating override material, manipulating hair&fur, creating new objects in heavy scenes, ... - but all these problems should occur exactly identically in previous versions
• We know there are unnecessary restarts, for example when navigating slate editor - but again, the same problem was in every Corona version with interactive
• There are unnecessary restarts with 3dsmax physical camera. They are solved to switching to Corona camera. The physical camera in general is quite bugged w.r.t. notification system. Going from old max to new max will give you feeling of slower interactive due to switching from standard camera to physical camera
• There is another issue, where moving around viewport is more heavy on main thread when using camera than free viewport. Just moving the camera around could make the main thread 100% busy, so there is no time for IR to update. We have an idea how to fix this, but it involves waaay too heavy changes. On the other hand, it should also fix stuff like materials not expanding in slate or render region not working. It will require a lot of time to implement. But again, this should be broken exactly the same in older corona versions

[Dalton Watts]

Like fraine7 and others have reported I too can't put my finger on why exactly IR feels much slower on my Dual Xeon 2696v3 system because frankly, I haven't had the time yet to isolate this and especially to figure out when exactly did it start to underperform. It is something very noticeable though.

This bothers me because IR was THE main factor that made me switch to Corona.

[davemahi]

I have a dual Xeon and I am noticing IR to be slower too. Sometimes I find it faster to just keep hitting Render over and over than using IR.

I thought it was just me, but I do notice it.

[maru]

I have a dual Xeon and I am noticing IR to be slower too. Sometimes I find it faster to just keep hitting Render over and over than using IR.

I thought it was just me, but I do notice it.

Have you already contacted us about this through our support? Of not, then it would be greatly appreciated: https://coronarenderer.freshdesk.com/support/tickets/new
We would then ask some extra questions, and log your case in our internal tracker.

[Dalton Watts]

I reckon that, now, using Corona 1.7 hotfix 3, IR doesn't feel that much slower than 1.6 on my dual Xeon workstation :)

[romullus]

I don't have problems with IR slowness or unresponsiveness (maybe because my scenes aren't big and complex enough), but i noticed that Corona tkaes much more time to start IR for a very first time then it used to be, even in the most basic scenes. Can't say exactly when i start to notice that, but it is like that for months now. Anyone else has similar impression?

[Christa Noel]

... but i noticed that Corona tkaes much more time to start IR for a very first time then it used to be...

yes, same here

[NicolasC]

but i noticed that Corona tkaes much more time to start IR for a very first time then it used to be, even in the most basic scenes. Can't say exactly when i start to notice that, but it is like that for months now. Anyone else has similar impression?

Same here ....

[PROH]

.... and here ...

[snakebox]

Yup, again I don't have hard data but it would be interesting if anyone have corona 1.3 or 1.2 sitting around to do a comparison with a current scene?

[effilang]

Same, dual xeons also.

[maru]

Guys, once again, it is best to contact us about this issue at support@corona-renderer.com and provide as much info as possible: problematic scene, screenshots, video recordings, anything that would help us understand the issue and reproduce it.
Currently we are not able to confirm any of the slowdown reports. We have already tested the reported scenes on various computers including i7s, dual xeons, threadrippers. Most of the reports rely on a "feeling" that something is slower, without much evidence confirming it. We really need good reports showing us the numbers and the behavior of IR. Only then we will be able to share the report with our QA, developers, and other guys who will be able to look into this.