Multiple Maps in Scene Env loads all of the textures at rendertime when disabled

[HalukOzkul]

I render different frames with different lighting setups and keep all of the HDRI's in the Multiple maps list. I only use one HDRI at a time as a Single Map, the Multiple maps tab is always disabled.

For some reason, Corona loads every HDRI in the Multiple maps list when it's disabled. I'm not using LightMix or any on the LightSelect render elements. These textures are not assinged to any other object in the scene. They only live in the Multiple Maps list which is, again, disabled.

The problem is, I'm already working with very heavy scenes and loading multiple unused HDRI maps really messes up the memory usage. I get the memory warning and it's always the HDRI maps hogging the memory.

I think this was an oversight, I can't think of a reason for Corona to load unused textures. Any fixes for this is very much appreciated.

[Avi]

If a HDRI/Texture is being used during rendering, they will be loaded in RAM. Maybe your HDRI are being used in the lightmix setup during rendering.

You can also use out of core rendering for texture. You can read more about it here: https://support.chaos.com/hc/en-us/articles/9477508142993-Out-of-core-Rendering-for-textures-3ds-Max

[arqrenderz]

But he says that is not using lightmix, and corona is loading those hdri assets as it says on the memory breakdown list isn't ?

[Avi]

I render different frames with different lighting setups and keep all of the HDRI's in the Multiple maps list. I only use one HDRI at a time as a Single Map, the Multiple maps tab is always disabled.

For some reason, Corona loads every HDRI in the Multiple maps list when it's disabled. I'm not using LightMix or any on the LightSelect render elements. These textures are not assinged to any other object in the scene. They only live in the Multiple Maps list which is, again, disabled.

The problem is, I'm already working with very heavy scenes and loading multiple unused HDRI maps really messes up the memory usage. I get the memory warning and it's always the HDRI maps hogging the memory.

I think this was an oversight, I can't think of a reason for Corona to load unused textures. Any fixes for this is very much appreciated.

Hi, I am currently investigating and discussing this issue with our devs. Will update you.

[Avi]

Hi,

I discussed this further with our devs, and it seems like this is expected as once the bitmap is loaded for the given scene it remains in memory until it is removed from the scene. Since the bitmap is still part of the multimap (part of the scene), it remains in the memory. This is needed by 3ds Max for various operations such when you open the material editor. Keeping it in memory prevents the need to reload it multiple times, which could otherwise lead to performance issues.

As a workaround for now, we recommend removing any unused HDRIs from the scene entirely if you don't want it to load in RAM and you can also use out of core corona feature if you are running out of ram.
https://support.chaos.com/hc/en-us/articles/9477508142993-Out-of-core-Rendering-for-textures-3ds-Max

We have also logged this in our system to see if we can further improve this in future.

(Report ID=CMAX-1240)

[HalukOzkul]

Hi Avi, thank you for the investigation and your reply.

The explanation makes sense, but I'm afraid it won't be easy to fix this without some changes to the 3dsMax itself right?
I'll try to figure out a workaround, I'm thinking a separate max file containing the light setups and to only copy over the necessary HDRI texture.

I'll keep an eye on the changelogs.

@arqrenderz also thank you for the heads up you gave to Avi :)