Arnold Stand-in issue

#1

Hi, recently i made two separate scenes which i want to import as a arnold stand-in in an other one. I exported the objects of both scenes as an ass file. Everything seams working fine but when i import them in a new scene as stand-ins i see that one is imported correctly and the second one has changes texture and is now colored with the texture of the first one. I tried to play around with the override settings and things like that but nothing works.
Does somebody knows what the problem is and how i can import multiple stand-in and keep their shaders and textures?
Thanks!

#2

Maybe the shaders and textures have the same name?
e.g. if you have a shader called “wall” in both archives, arnold defines the shader the first time it appears and uses it for all shaders called “wall”. So if you have the same shader in your second archive, it will receive the same shader as the first one.

#3

Yes this could be the problem. I will check and try to change the name.
Thanks so much :keenly:

#4

Unfortunately this is still not working. I changed the names of each shader and texture file but i get the same error as before. Has somebody an other suggestion?

#5

In cases where same shader occurs in multiple cases, you should see warning in the output window. Set the debug mode to Warning+Info or to Debug and have a look at the messages in the output window, maybe you see something helpful.

#6

No, ok i saw that the .ass shaders and texture files will constantly overridden by the scene shaders. I imported a stand-in ass file into a scene with many different materials and texture files and I saw that it gets one of these and I also could assign a new material to the stand-in. This means that there is the override option turned on. But i want that it gets the textures of the original scene and not an overridden material. How can i turn the override option off, because i could not find it.

#7

Standin->renderstats.overrideShaders

#8

For unknown reason it’s still not working. Did I missed something with environmental variables or similar things because I didn’t set up anything. I tried to uncheck everything what could override my information. In a empty scene with only one ass file everything is fine but the second can’t find the proper shaders. Any suggestions?
Environmental variables?
Render settings?
Tutorials?

#9

If i understand you right, you export *.ass with shaders(which has unique names, as well as each node in shading network) and than import them in render scene? And there are no shaders in render scene? Does you render scene as simple as you describe - just 2 objects imported as arnold standins? Just to check — try clean cashes(Arnold>flush cashes>textures).

First, what comes to my mind - naming, everything should work fine if you careful with names of nodes in shading networks(materials, textures, utilities etc). Researching arnold bring me to a workflow, where standins is basement of creation complex scenes. Each object, which has heavy geometry or which is cloned many times i convert to standin(without shaders) and i have no such issues with them.

Tutorials?.. May be here you can find some usefull info: http://www.kiryha.blogspot.com/2014/02/render-notes.html

#10

Yes in fact when i import the stand in there is no material shader in the hypershader window. However I will import the scene as a reference and view them as a bounding box to keep everything fast. It works also very well. I don’t know maybe a little bug. But thanks for the reply. :thumbsup:

#11

When you export object to ass with, shader exists in this ass. When you import standin, shader would not appear in hypeshade.
There is no need to use references to keep everything fast, cos standIn functionality is even better than references. You can switch display of standin between bounding box and shaded geo.

#12

I had the same issue with a very big scene with several characters with animation. I convert each character to Stand-In and when import each one to a new scene with the environment (also Stand-In) characters end up with materials of other characters, also some materials on the background end up with other materials.

I try many things and at the end i end up having to convert all the characters in the same scene at the same time to a huge Stand-In sequence. So i was having one animated Stand-In for all the characters and one for the environment and only then the issue with the materials got resolved.

#13

I think, applying materials at the highest level of referencing will save from any mess-up issue. No meter what shader do you have in ASS, overwriting it in render scene should solve problem.

#14

As mentioned, the problem is that Arnold does not encapsulate standins in their own namespace. That means that not only surface shaders will be overwritten, but every single shading node. This can happen with a file texture node, a multiply divide node or others.

Our solution here is to prefix all nodes with a special unique string before we export to ass files. And it works really fine.

#15

Thanks Guys.

What do you mean by applying materials at the highest level of referencing?.. And overwriting the shader…, do you mean checking off the option in render stats > Override StandIn Shaders witch is on by default…

Interesting, will try that.

#16

You export geo to ass without any shaders.
Apply shaders on standin after you import standin into the scene. This tehnique require separate standin for each material.

#17

Got it Kiryha, thanks.