material editor SLOW - i think its a CORONA issue?

[shortcirkuit]

Hi devs,

This material editor is driving me crazy (its been years) - ive tried restarting/merging scenes/scene cleanup scripts etc.  So i decided to do a quick video on switching between 2 corona materials and 2 standard Physical materials (from max).  Look how much quicker it is to swap between physcal materials vs corona materials.  It seems to be a corona issue?  or am i mistaken?

[maru]

I have personally never ever experienced a slowdown close to this. I am attaching a recording from a Ryzen 3900X, 3ds Max 2025, Corona 12 HF1.
Please provide basic details such as your CPU model, Windows version, 3ds Max version, Corona version.
Also, is this happening in any scene, or only in some specific one(s)? For example, if you take an empty scene and open the material editor, is it the same? Or does it only happen when a heavy scene is loaded?
Is this happening right after you start 3ds Max, or you need to work with the scene for some time and only then it starts happening?

[romullus]

What is your viewport texture display settings? Try to set baked procedural maps resolution to really low value and see if that improves your experience.

[muoto]

same feeling here (corona12 hf1, max2024 or max2025, nvidia rtx4090)... material UI is sooooo slow, even on a complete new empty scene

baked the 128px didn't change anything

[shortcirkuit]

Specs are as follows:
Threadripper 5995WX
256 GB RAM
4090 GFX card.
Win 11.

Corona Daily 30 July

My baked procedural map was 2048.  Ill try 128.

As for when it happens, mostly after opening an existing interior scene and usually after some time.  MOst new scenes appear to work ok and then it gets bogged down!  Still never as fast has Maxs physical material editor

I have personally never ever experienced a slowdown close to this. I am attaching a recording from a Ryzen 3900X, 3ds Max 2025, Corona 12 HF1.
Please provide basic details such as your CPU model, Windows version, 3ds Max version, Corona version.
Also, is this happening in any scene, or only in some specific one(s)? For example, if you take an empty scene and open the material editor, is it the same? Or does it only happen when a heavy scene is loaded?
Is this happening right after you start 3ds Max, or you need to work with the scene for some time and only then it starts happening?

[pokoy]

This is due to the fact that Autodesk ported (almost) all of their UI to Qt, while Corona still uses the win32 UI framework, so any materials from Max will display its UI faster.

Vray rewrote their UI to Qt, see the blog post here:
https://www.chaos.com/blog/the-qt-fication-of-v-ray?srsltid=AfmBOooGKkMEzBLEyVe5Ma_jz6IcgspWyJhZO02MDPrmk3QyDbe6-AN9

The upside of a UI port to Qt is a much snappier UI. The downside is that it takes effort and time and can get complicated.
Corona has avoided porting the UI to Qt for some reason (only VFB2 uses Qt right now as far as I know), probably due to the fact that supporting old max versions would force them to take care of two UI frameworks for each release and UI component. Still, a switch to Qt is long overdue.
Autodesk started porting to Qt in 2016 if I'm not mistaken and finished porting most UI elements in 2019/2020 (with some exceptions though that still make Max slow at redrawing the UI).

tl;dr - unless Corona doesn't port their UI to Qt you will not see any improvement.

[Aram Avetisyan]

This is due to the fact that Autodesk ported (almost) all of their UI to Qt, while Corona still uses the win32 UI framework, so any materials from Max will display its UI faster.

Vray rewrote their UI to Qt, see the blog post here:
https://www.chaos.com/blog/the-qt-fication-of-v-ray?srsltid=AfmBOooGKkMEzBLEyVe5Ma_jz6IcgspWyJhZO02MDPrmk3QyDbe6-AN9

The upside of a UI port to Qt is a much snappier UI. The downside is that it takes effort and time and can get complicated.
Corona has avoided porting the UI to Qt for some reason (only VFB2 uses Qt right now as far as I know), probably due to the fact that supporting old max versions would force them to take care of two UI frameworks for each release and UI component. Still, a switch to Qt is long overdue.
Autodesk started porting to Qt in 2016 if I'm not mistaken and finished porting most UI elements in 2019/2020 (with some exceptions though that still make Max slow at redrawing the UI).

tl;dr - unless Corona doesn't port their UI to Qt you will not see any improvement.

This is the all info you need in regard to this.

I will just add that when switching from same type to same type (e.g. from CoronaPhysicalMtl to another CoronaPhysicalMtl, or from CoronaColor to another CoronaColor), the change should be instant or much faster than switching to another type (at least for SME, I have declined to use Compact material editor straight from from Max 2011).
I have also noticed that the longer 3ds Max is open between sessions/scenes, the slower it can get. To get the best performance, you need to restart 3ds Max (it will still not be as fast as Physical or VRayMtl).

[shortcirkuit]

hardly a solution though - to restart!  Such a waste of time.  Some of my scenes take 10 mins to open!  WOuldnt it be best to get to the root cause of the issue?
If what @pokoy has written to be true, then surely we need to get up to speed (QT).  Today for instance, i think i wasted up to an hour or so opening scenes so it works properly for little while.  It just all feels so 1995 pentium clunky at times and i have a pretty beefy machine.

This is due to the fact that Autodesk ported (almost) all of their UI to Qt, while Corona still uses the win32 UI framework, so any materials from Max will display its UI faster.

Vray rewrote their UI to Qt, see the blog post here:
https://www.chaos.com/blog/the-qt-fication-of-v-ray?srsltid=AfmBOooGKkMEzBLEyVe5Ma_jz6IcgspWyJhZO02MDPrmk3QyDbe6-AN9

The upside of a UI port to Qt is a much snappier UI. The downside is that it takes effort and time and can get complicated.
Corona has avoided porting the UI to Qt for some reason (only VFB2 uses Qt right now as far as I know), probably due to the fact that supporting old max versions would force them to take care of two UI frameworks for each release and UI component. Still, a switch to Qt is long overdue.
Autodesk started porting to Qt in 2016 if I'm not mistaken and finished porting most UI elements in 2019/2020 (with some exceptions though that still make Max slow at redrawing the UI).

tl;dr - unless Corona doesn't port their UI to Qt you will not see any improvement.

This is the all info you need in regard to this.

I will just add that when switching from same type to same type (e.g. from CoronaPhysicalMtl to another CoronaPhysicalMtl, or from CoronaColor to another CoronaColor), the change should be instant or much faster than switching to another type (at least for SME, I have declined to use Compact material editor straight from from Max 2011).
I have also noticed that the longer 3ds Max is open between sessions/scenes, the slower it can get. To get the best performance, you need to restart 3ds Max (it will still not be as fast as Physical or VRayMtl).

[shortcirkuit]

also - its not instant from corona phy material to coroan phy material as you can clearly see from my initial video i posted.

This is due to the fact that Autodesk ported (almost) all of their UI to Qt, while Corona still uses the win32 UI framework, so any materials from Max will display its UI faster.

Vray rewrote their UI to Qt, see the blog post here:
https://www.chaos.com/blog/the-qt-fication-of-v-ray?srsltid=AfmBOooGKkMEzBLEyVe5Ma_jz6IcgspWyJhZO02MDPrmk3QyDbe6-AN9

The upside of a UI port to Qt is a much snappier UI. The downside is that it takes effort and time and can get complicated.
Corona has avoided porting the UI to Qt for some reason (only VFB2 uses Qt right now as far as I know), probably due to the fact that supporting old max versions would force them to take care of two UI frameworks for each release and UI component. Still, a switch to Qt is long overdue.
Autodesk started porting to Qt in 2016 if I'm not mistaken and finished porting most UI elements in 2019/2020 (with some exceptions though that still make Max slow at redrawing the UI).

tl;dr - unless Corona doesn't port their UI to Qt you will not see any improvement.

This is the all info you need in regard to this.

I will just add that when switching from same type to same type (e.g. from CoronaPhysicalMtl to another CoronaPhysicalMtl, or from CoronaColor to another CoronaColor), the change should be instant or much faster than switching to another type (at least for SME, I have declined to use Compact material editor straight from from Max 2011).
I have also noticed that the longer 3ds Max is open between sessions/scenes, the slower it can get. To get the best performance, you need to restart 3ds Max (it will still not be as fast as Physical or VRayMtl).

[dj_buckley]

Yup, "Get with the times" springs to mind.

[James Vella]

Some of my scenes take 10 mins to open! 

Not related to the UI topic however if your scenes take 10 minutes to open, I would certainly start to optimize - proxy out large mesh(s), xref items that can be delayed or turned off until render time etc.

[pokoy]

A UI port to Qt will help with displaying the UI faster, not necessarily scene open times.

As James says, a few things to keep in mind when scenes take very long to open:
- Max rebuilds caches on scene loading for materials/maps. It is supposed to re-use caches that were built/used in the past but clearly this system is not reliable. Autodesk uses a directX-related HLSL parser from Microsoft for the HQ mode in the viewport and it's basically a black box to them. Max' Nitrous viewport engine is really outdated by now as it was designed some 15+ years ago.
Scene sizes, material counts, texture sizes and counts etc have grown over the years, and Max development never caught up.
- Nitrous is really fast for pure geometry drawing but will not perform well in HQ viewport mode for the reasons above. Make sure you use Standard viewport mode for ALL viewports and disable map display when saving - this will be a much faster mode and will not trigger a cache re-building when re-opening the scene.
- As Romullus suggested, switching texture sizes to smaller values will also help if texture caches are being built.

In short, if you're using HQ viewport mode, try to use Standard mode everywhere, save and re-open. If it's faster, HQ is the bottleneck.

I have no idea how it is in 2024 (I'm still on max 2021) but on my production scenes, switching to HQ mode even with maps disabled will hang Max, some objects will just disappear (while still being selectable) - a sign of the caching system failing.
I can't even open Slate or the Slate material browser, it'll build previews for all maps/mats and will take 25+ minutes on any of the bigger scenes I have. Not sure if Slate 2.0 improved anything but my guess is... no. I'm still using the old Mtl browser from Compact Ma- Ed for this reason.

Autodesk doesn't test too much, at least not with production scenes typical for what we do, and they don't check for 3rd party compatibility, that's up to the 3rd party to provide.
It's possible some problems arise from the combo of Max (with all its subcomponents developed at different times by different teams who are long gone) plus Corona but that would be on the Corona team to investigate. Which can be really hard since sometimes there's no documentation on important changes from the Max development team, and if you want to support multiple Max versions you need to track each one on its own.

And then check, of course, for all the other possible issues - slow network connection, plugins that rebuild their geometry (Scatter, Forest etc), loads of HDRs in the material editor or submaps, texture count and sizes.

[shortcirkuit]

Thanks for the detailed info - i think youre right baout how autodesk havent caught up to the higher demanding scenes.  I feel as though things have gotten slower (ie load times) - more interested to see if the Corona devs can do anything about it though regarding the material editor.

A UI port to Qt will help with displaying the UI faster, not necessarily scene open times.

As James says, a few things to keep in mind when scenes take very long to open:
- Max rebuilds caches on scene loading for materials/maps. It is supposed to re-use caches that were built/used in the past but clearly this system is not reliable. Autodesk uses a directX-related HLSL parser from Microsoft for the HQ mode in the viewport and it's basically a black box to them. Max' Nitrous viewport engine is really outdated by now as it was designed some 15+ years ago.
Scene sizes, material counts, texture sizes and counts etc have grown over the years, and Max development never caught up.
- Nitrous is really fast for pure geometry drawing but will not perform well in HQ viewport mode for the reasons above. Make sure you use Standard viewport mode for ALL viewports and disable map display when saving - this will be a much faster mode and will not trigger a cache re-building when re-opening the scene.
- As Romullus suggested, switching texture sizes to smaller values will also help if texture caches are being built.

In short, if you're using HQ viewport mode, try to use Standard mode everywhere, save and re-open. If it's faster, HQ is the bottleneck.

I have no idea how it is in 2024 (I'm still on max 2021) but on my production scenes, switching to HQ mode even with maps disabled will hang Max, some objects will just disappear (while still being selectable) - a sign of the caching system failing.
I can't even open Slate or the Slate material browser, it'll build previews for all maps/mats and will take 25+ minutes on any of the bigger scenes I have. Not sure if Slate 2.0 improved anything but my guess is... no. I'm still using the old Mtl browser from Compact Ma- Ed for this reason.

Autodesk doesn't test too much, at least not with production scenes typical for what we do, and they don't check for 3rd party compatibility, that's up to the 3rd party to provide.
It's possible some problems arise from the combo of Max (with all its subcomponents developed at different times by different teams who are long gone) plus Corona but that would be on the Corona team to investigate. Which can be really hard since sometimes there's no documentation on important changes from the Max development team, and if you want to support multiple Max versions you need to track each one on its own.

And then check, of course, for all the other possible issues - slow network connection, plugins that rebuild their geometry (Scatter, Forest etc), loads of HDRs in the material editor or submaps, texture count and sizes.

[Juraj]

I will oppose all the advice in this thread, because I can already tell you, it will not help. Any big-PC (Threadripper, Xeon, etc..) in high-core version, is pain like this in material editor unless as you correctly shown, you use native Physical Material.
Corona, will have super slow material editor in any remotely sized scene. And it's not snappy even in completely empty scene, unlike native.

This has absolutely nothing to do with proxies. This is technical issue on Corona's side that they just don't care about. I guess majority of users aren't on 64-core machines.

BTW, my settings:
Standard viewport (so no HQ)
Every big mesh is proxy. (most of long opening is due to bugs like "corona assets" etc.. and similar stuff, having proxies makes scenes smaller, but it hardly makes difference in opening after scenes start to feature bloat).
Viewport texture settings 1024px for all 3 types(laughably blurry, so despite having 16GB of Vram, I only use like 2GB per scene because otherwise everything will be even slower).
Basic material editor for editing materials. I only use Slate to create them, but because it's so slow, all the little changes (changing IOR 10perc. here or there, etc..) I do in basic.
All textures mapped locally, on local disc with exact paths.
No plugins whatsoever. No ForestPack, no nothing.
It doesn't matter which Max version. It's the same as long as I can remember. Really makes zero difference.

It's not anything else, it's Corona. Yes you are correct.

This does in no way help with slow material editor, and esp. slow material editor during IR. That's like unusable, I waste like 90perc. of my time and 99perc. of my mental health waiting on shit to unfreeze.
It's what it is :- (.

If it's really all because of QT, then that should have been tried ages ago.

One thing I never tested, if it's connected to materials being applied to scene ( and/or additionally, having "shown in viewport"). So I will test:
- disable show in viewport in big heavy scene
- dis-apply all materials (I don't know, apply them to single box and hide it) just keep big material editor full of materials.

[hurrycat]

I have to add to this, in hopes of strengthening our point here, that the Material Editor is the single biggest burden to our everyday productivity. We constantly have to deal with scenes that are populated with thousands of proxies and geometries, Scatters, Forest Packs and everything remains relatively snappy on a 3970x with 128gb ram except for the material editor, using nothing but Corona Materials.

We are using the SME exclusively and I have to say that the heaviest SME slowdowns we are experiencing are during IR, even after limiting the number of cores used for rendering.

Trying to replicate this behaviour in a fresh new Max Instance is unrealistic and very far from real world usage scenarios. Also, restarting Max can be a pain when opening scenes and starting IR can easily take 15 mins and we often avoid it unless Max crashes lol.

Already voted for it in the Ideas Portal, porting to Qt is long overdue and will save us not only time but frustation as well.