Vantage Live Link - Volumetric Scattering Issue

[Saii]

I have been testing out the Vantage live link recently and come across a few issues.

One with roughness which is already being looked at. (Report ID=CMAX-1460)

The second however is to do with the "Distance" setting within Volumetric Scattering. I have a glass with distance set to 2mm, but to get the same desired look in Vantage, I have to change this setting to 0.2mm. I am unsure if this is a scale issue within vantage? Or is it a bug when translating the units across?

I have attached both measurements to show the comparison.

Thanks

[maru]

Please always state which exact version of Corona, 3ds Max, and any relevant plugins you are using. This specific issue should already be fixed in Corona 13. Please see my attached video.

[Saii]

We are currently using Corona 13, Max 2024 and plugins such as Forest Pack and Railclone.

I can see your demonstration of the Volumetric Scattering working. However my issue is that it does not match the values in Interactive from Corona. Can you try and start a render in Max with one value. Then see what this looks like in Vantage. I found I had to adjust the values, from 0.2mm to 2mm to get the same desired outcome.

[Saii]

I have done another test to simplify the experiment. Created a simple teapot, applied a Corona Physical Material. Volumetric Scattering set to 50mm.

Attached screenshot of the result. Left Corona Interactive. Right Vantage.

For Vantage to look like the renders in Max, I am having to divide the Volumetric Scattering distance by 10. So 5mm would give the desired result.

[maru]

Here you go. It seems to be working correctly. I have my absorption distance set to 50 and I am just starting the live link.
Note that how volumetric absorption looks depends on scene exposure. Currently, Vantage doesn't use the same exposure than you Corona rendering. So you may need to enable automatic exposure or lower the exposure in Vantage to get a result comparable with Corona in Max. For example, if the exposure is higher than in Corona, the absorption may look more "transparent" (as if it was set to a higher distance).

[maru]

I have done another test to simplify the experiment. Created a simple teapot, applied a Corona Physical Material. Volumetric Scattering set to 50mm.

Attached screenshot of the result. Left Corona Interactive. Right Vantage.

For Vantage to look like the renders in Max, I am having to divide the Volumetric Scattering distance by 10. So 5mm would give the desired result.

I am sure this is caused by having too high exposure in Vantage.

[Saii]

Thanks for the work you're putting in here.

I have tried to copy your steps to recreate this. I have attached a screenshot for lowering and setting exposure to automatic. I cannot seem to get the same desired effect though.

I have tried to attach my Max scene in case that helps at all. Apologies if this is not the correct procedure for sending the scenes.

We use Millimetres for our scene units, I wonder if that has any effect here?

[maru]

Thank you, I will look into it some more. My random guesses now are:
- scene units, good call
- the fact that the teapot is a non-closed geometry

[Saii]

I have done some further testing. I think I may have been correct about the scene units.

I have attached two examples. I have tried to recreate the same scenarios in both. With the Teapot being the same scale and volumetrics having the same distance.

01 Being in MM
02 Being in CM

It does seem there seems to be an issue with converting the scene into Vantage whilst using MM as your scene measurements?

[maru]

Thanks for your tests and sorry for my self-confidence regarding the exposure. :)

I tried reproducing this, but everything is working fine here. I am attaching a recording. If you are doing something differently, can you please explain what? And/or add your recording if possible.

[Saii]

Hi Maru, thanks for doing these tests. To clarify, I changed the display Units as well as the System Unit scale. In my above post I tried to include as much in the screenshot as possible. (On the far left of the images to show both being in cm then both in mm)

I have attached a screenshot of just the units if needed.

[maru]

Thank you, I missed the system units part. This is now reproduced and logged as (Report ID=CMAX-1798).

[Saii]

Amazing, thank you for your help. I will try and keep an eye out for this.