Will converting images to tiled exr's via img2tiledexr help with memory?

[leuey]

I have a scene with a ridiculous number of images - something like 500 png texture maps, most of them 4K. As you can imagine this takes a huge amount of memory - I have 128GB in the workstation but I'm running out. Will converting images to tiled exr's help save on memory at render time? I'm not really clear what the benefit is (looking at the docs). The other issue is the final render is a spherical pano - meaning that *everything* is in view of the camera.

[boyan]

Hey, Greg!

I have 128GB in the workstation but I'm running out.

I'm guessing but you've been used progressive to render a high-resolution image. Please avoid usage of progressive render with a high-resolution image and use bucket render instead of that.

As for the rest, check the latest nightly now we have compatibility with Modo's Spherical camera VR as well if you don't like the V-Ray's camera.

Cheers,

[vladimir.nedev]

If you convert the images to tiled EXR, they can be dynamically loaded and unloaded during rendering as needed.
This can help you render very large scenes that otherwise would spill to the Windows page file (which is usually slower) or just crash if you reach the page file limit.

The dynamic loading/unloading is disabled by default.
To enable it you must set the Dyn. memory limit option to a non-zero value.
This dynamic limit will be used for both dynamic subdivision/displacement, as well as tiled EXR files.

Or you can set the VRAY_TEXTURE_CACHE environment variable in Windows (needs Modo restart to take effect).
Setting this variable to a non-zero value will create a separate dynamic cache just for tiled EXR files.
From the help ( https://docs.chaosgroup.com/display/...es-CommandLine )
"""VRAY_TEXTURE_CACHE ? Specifies the size, in megabytes, of a separate texture cache to be used for tiled OpenEXR files. If this is not present, or the value is 0 , the same cache is shared between dynamic geometry and tiled textures. One of the advantages of a separate texture cache is that it is persistent across the frames when rendering an animation."""

When this separate cache is created, the following message will be printed in the Event Log "Creating texture cache with size XXX MB", where XXX is the value of the VRAY_TEXTURE_CACHE environment variable.

And yes, you need to render with buckets, as the progressive rendering tends to load tiles all over the image and this will degrade performance.

Greetings,
Vladimir Nedev

[leuey]

Thanks - I will render Adaptive. 2 follow-ups.

1. Can I used MODO's 'save as' to convert the images to tiled exrs? (rather than the V-Ray utility?).

2. Vladimir - when you say set Dyn memory limit to a non-zero value...is there a recommended value? I'm not using the denoiser, btw.

thanks,

Greg

[vladimir.nedev]

1. I am not sure, you can try and see if it works.

2. It depends on how much RAM you have and how much RAM the non-dynamic part of your scene takes.
You can set it to a negative value as well, which means use all RAM minus the value, so -1000, means use all RAM minus 1000 MBs.
In your case, maybe -20000, i.e -20 GBs will be a good value, it should be enough for the static geometry, Modo, your other open apps, etc. and you are left with 100+ GBs for the textures.

Greetings,
Vladimir Nedev

[leuey]

Awesome - thanks for the info, I'll do a test with MODO's 'save as' (doing it using MODO's command will let me keep the shader tree in-tact without have to 600 images...