vray env fog issue

[super gnu]

is this feature *totally* supported?

ive got a map in the fog transparency with a very low multiplier (0.35%) to add a small colour shift. this uses a gradient ramp driven in mapped mode by a distance tex. in theory all supported features. the analyzer gives no errors.

my render however looks dreadful when rendered using the vrscene exporter. as if the map is on 100% or something.

if i turn off the map, it *still* renders differently to standard max render.

i do have some lights with include/exclude and some of them excluded from illuminating the atmosphere, but given the fog looks darker in some areas, rather than brighter, i doubt thats it.

[super gnu]

im trying to upload example renders but i get an error.

[aleksandar_ivanov]

Could you attach (or send) the scene so we can take a look? Mention your 3ds max, V-Ray versions, and Cloud Job ID as well.

[super gnu]

hi, i have opened a ticket here: #76668

with files attached.

please note i dont have a cloud render job ID , i didnt bother wasting credits on a test since a simple test with vrscene export/render gave a totally wrong result, so i assume cloud would be the same, using standalone as it does.

[aleksandar_ivanov]

Thank you for the provided files and information. Let's continue the conversation there to make sure everything is in sync...

[vladie]

Hi,

Just posting the resolution from the ticket for everyone's sake who is reading.

We found that this behavior is related to several different reasons:

1. The 2D maps in VRayEnvironmentFog are not supported yet, the same behavior is observed when rendering with V-Ray Standalone and in Chaos Cloud too. This issue is reported in our internal system for fixing.
2. Also we found that when we are using any map in the Refraction slot in VRayMtl, there is a discrepancy between the render in V-Ray for 3ds Max and the V-Ray Standalone/Chaos Cloud render. The issue is reported in our internal system for fixing.

There's not an easy workaround of this issue but if you'd like you could try our VRayVolumeGrid to see if it could fit in your scene's setup. You could read more about it here.

Thanks,
Vladie

[Joelaff]

Thank you for sharing the resolution here. It drives me nuts when problems come up on the forum and then they move to a support ticket, never to be publicly resolved so everyone can benefit.

[super gnu]

its odd because i dont think i had any 2d maps in the env fog... a distance tex driving a gradient ramp to change the colour based on distance from an object. , which, as far as i understood it, are both 3d? it also works fine in standard max vray.

[aleksandar_ivanov]

The Gradient ramp map is a 2D map, there are no X,Y, or Z coordinates like in the Noise map for example. They will work as expected in the 3D host application, the issue appears when we exported them to the Cloud or Standalone.
If you like, you could you attach (or send) the scene so we can take a look?

[super gnu]

The Gradient ramp map is a 2D map, there are no X,Y, or Z coordinates like in the Noise map for example. They will work as expected in the 3D host application, the issue appears when we exported them to the Cloud or Standalone.
If you like, you could you attach (or send) the scene so we can take a look?

i have already sent a scene, as per the previous posts in the thread.. i guess the gradient ramp is the issue then... i wonder if i could use nested distance texes with different falloff distances to approximate the gradient in a 3d way... sounds messy.