Purge unused materials removes materials used by V-Ray proxies

[kubbek]

I am not sure if it could be addressed but maybe there is some solution. In modo complex shader tree can slow down performance significantly so I use frequently "Purge unused materials" command. Unfortunately it results in deleting materials that are used by V-Ray proxies.
Would it be possible to inform modo about connection between proxies and their material?

Jakub

[vladimir.nedev]

How do you connect the proxy to the material - using a material mask or an item connection ?
Can you send me or attach a simple scene that exhibits this behavior ?

I can reproduce this somewhat, but the "Purge unused materials" command seems to be behaving strangely.
Sometimes it will delete the proxy material / sometimes not.

Greetings,
Vladimir Nedev

[kubbek]

Here are links my simple test scene:
https://dl.dropboxusercontent.com/u/...proxy_test.lxo
https://dl.dropboxusercontent.com/u/..._test_1.vrmesh

I tried using material tag and item mask assigning them to the mesh before converting to proxy and to proxy item. Purge unused material deletes always materials connected to my proxies.

I noticed some other things:
1. independent of proxy settings it is invisible in the viewport (I could be making something wrong as earlier my proxies inside modo looked as expected; in some of previous builts though)
2. when you select proxy item and click m for assigning material tag it is assigned to some other mesh in the item list and only some time.
3. is there a way to import saved proxies to the scene other than creating them inside this scene? There is only option "convert to proxy". I couldn't find any for importing existing ones.

Best,
Jakub

[vladimir.nedev]

I will look at the scene later. About the other issues :

1. The V-Ray Proxy items are considered "locators" by MODO. If you don't have "Show locators" checked in the "Visibility" properties of the 3D view, the proxy won't be visible. I don't think I can change this behavior with the current MODO API.

2. Once you export the .vrmesh file, you cannot assign materials to it anymore. The 'm' command will assign new material tags, which is not possible once the vrmesh file is written. I was thinking of adding a
command that will create material masks for all materials tags saved in the currently selected V-Ray proxy item(s). Without such command, you have to manually find the material tags in the "Polygon Tag" list in the mask item.
I mentioned a possible workflow in this post : http://forums.chaosgroup.com/showthr...838#post634838

3. There isn't a specific "import" command. You just create a "V-Ray Proxy" item from the "Add item" -> "V-Ray Geometry" and then choose the ".vrmesh" or ".abc" file in the "File name" field.

Also this thread has some more info on proxies : http://forums.chaosgroup.com/showthr...roxy-materials

Greetings,
Vladimir Nedev

[vladimir.nedev]

So I finally took a look at the problem with the "Purge Unused Materials" command deleting materials assigned to material tags from V-Ray Proxy items.
It turns out I had to give MODO at least one triangle with each material/part/selection tag that the V-Ray proxy has, or materials with these tags would get removed by the "Purge Unused Materials" command.
So for the next nightly build ( 2015-08-19 ) I am doing just that, this increases the number of "surface bins" that I give to MODO for each V-Ray proxy, so might result in slower OpenGL performance for the V-Ray Proxy item if it has a lot of materials inside it.

Note that even after these fixes the "Purge Unused Materials" command still doesn't work reliably.
For procedural geometry (like the Gear Item, V-Ray Proxy, MODO Deferred mesh), it doesn't work correctly when you have more than one level of nested material masks, it seems.
For example, if you have a mask on a V-Ray Proxy item, and inside it is a mask on one of the V-Ray Proxy material tags.

I am attaching three example scenes with MODO's gear item that have this problem. Running "Purge Unused Materials" after loading the scenes will delete material masks that actually affect the rendering.
I will send these to The Foundry. The scenes are created using MODO 901 SP1.

purge_unused_materials_bugs.zip

Greetings,
Vladimir Nedev

[kubbek]

Great you found time to look into this problem. Number of materials/material tags is one of subjects that affect modos performance. I use it a lot and it was a serious problem with v-ray proxies.

[vladimir.nedev]

Great you found time to look into this problem. Number of materials/material tags is one of subjects that affect modos performance. I use it a lot and it was a serious problem with v-ray proxies.

Like I said, the "Purge Unused Materials" command still doesn't work very reliably with V-Ray proxies, but there is nothing more I can do, I think.
You should be careful when using it. Hopefully The Foundry will fix the rest of the issues.

Greetings,
Vladimir Nedev