Can't remove volume shader from volume

[BrianDeMetz]

Just updated to version: MAXtoA-2.3.37.2018.exe

Now it seems creating a new volume even when checking box adds no shader. recreating over and over and finally a volume shader is created..

Then original volume shader can't be removed and I end up with 2 shaders if I try to add a new one. If I apply the original shader it clears the 2nd but applying the second doesn't remove the first so it ends up with 2 - so I have no way to change the volume shader. Is this a feature?

Thanks in advance.

[BrianDeMetz]

Anyone have any ideas on this? Just up'd to latest MtoA version and still seems to happen.

[Stephen.Blair]

What check box? How do you create a volume?

I create a volume shader in the Material Editor, and apply it to an object.

Then I create a surface shader, and apply that to an object, and the object renders with the surface shader.

I tested with a box primitive, so I had to add Arnold Properties and enable/disable the Volume settings.

[BrianDeMetz]

Hi Stephen - thanks for the feedback. If I create an Arnold volume, browse and choose a VDB, leave on checkbox to create a standard volume shader, I can never replace it with a new shader - it remains stuck on that shader. If I create one manually and assign it to the volume, then in the Mat Editor, it shows 2 shaders assigned but will always only use the original shader. All I can do is select the volume and right click on the 'volume shader' box and choose clear or cut, but then I can never assign it a new shader. Either I'm doing something wrong, or something seems broken.

Also, if when creating the volume, if I uncheck the box to create and assign a shader, I can never add a shader to the volume. It remains as 'No Mat' in the volume shader.

[madsd]

I am almost certain you are the victim of mixing workflows together, I saw you use the old material browser as well.

Now, we have several types of volumes, environment, VDB and as Stephen points out, you can enable volume rendering on any mesh in max with the Arnold properties modifier with enabling the Volume features in this modifier.

This last one, works like normal materials, you assign the material the volume material to the mesh.

VDB workflow is totally different, it has a slot, and you drag the small green dot from the volume material to this slot.

[BrianDeMetz]

Hi Mads, thx for the reply. Well I certainly don't want to be a victim ;] I use compact and slate mostly. Lately I've been using VDBs simmed from FumeFX/PFD but rendering in Arnold, so am making use of Arnold Volume specifically.

I've been trying to right click the active shader and select 'assign to selected' and that's where the problems are - it never assigns the new shader. For regular geometry it works fine. Green dot output drag seems to work for volumes, so that's resolved though seems strange it wouldn't work like geo. In any case, thx again - that'll do!

Sorry, can't seem to reply to you and not sure how I 'accept' your comment as the answer.

[madsd · Accepted solution]

Hi,
You cannot assign a material to a VDB, the VDB construct has a slot, slots does not accept "assign material by design" you need to physically drag and drop the green dot from Slate to the slot.
Volume material added to a mesh is done the same way you would add a normal material.

[BrianDeMetz]

Hi Mads, thx for that data. Seems to be working now - dragging the dot over to change shaders.

I still do have a scenario where I'm stuck with 2 shaders assigned to a volume and can't get rid of one of them. See image.

[madsd]

You can ignore that.

It is likely you accepted to have the slot prepopulated to the slot with a volume material when you load the VDB, and then also add your own.

But, the actual volume material getting rendered is the one attached to the slot at the momement you send the scene to the render engine.
So you could have 25 volume materials, and it would still only render the one currently assigned.

[BrianDeMetz]

Thanks Mads. Ignore it I shall. It seems to work fine anyway. Thx again for your time!

[madsd]

Right.
The thing was just, that you were looking at this as some kind of important aspect, when all that is, is just showing some pool of materials.

You main concern is only what is attached to the assets, not so much what is in the material editors, or lists in mat browser.

But you are sorted out, so have a nice one!

[BrianDeMetz]

Thanks - you too!