OpenMaya C# Standalone

Coding
#1

Hey Guys,
Has anyone successfully created a C# standalone, that can push changes into Maya, from the the OpenMaya API?

The goal I was aiming for, was a standalone software that could do basic things within a maya scene, like get scene DagNodes, the Dependancy graph, read skin cluster data, or export selections.
I have run a few tests and get the following error every time I use the OpenMayaCS.dll, in my C# project.

"An unhandled exception of type ‘System.BadImageFormatException’ occurred in MyStandalone.exe

Additional information: Could not load file or assembly ‘openmayacs, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null’ or one of its dependencies. An attempt was made to load a program with an incorrect format."

I’ve looked into all the standard fixes for library load failures, and I am being to assume it just cant be done.
Was hoping someone here might have some experience with this, they can share, or pose a possible alternative.

Im using: maya 2014 sp7, Visual studio, .Net 4.5.2

Cheers,
-K

#2

I haven’t tried this, but I suspect you’ll need to use pinvoke.

#3

I don’t believe the openMaya dll includes an actual running Maya: I think it’s just a wrapper around OpenMaya, so i believe it won’t have anything to talk to if run from outside of Maya.

You could maybe write your app as a plugin using the C# api and control Maya from there, passing args on the command line to a headless maya instance

#4

You can load foundation.dll and you’ll have a functional copy of Maya. Here there be dragons.

#5

Oh, BTW, if you want C# to talk with a running copy of Maya directly, I’ve done that both via Maya’s built in command port and by writing a WCF framework to do RPC like calls into Maya. For anyone not willing to pour weeks learning WCF/Python.net, I recommend the command port route.

EDIT: And someone tell me if I’m wrong, but you have to use a real TCP/IP port on Windows. *nix style named pipes seem to be completely bogus on Windows.

Don’t forget that mayabatch.exe is still always an option as well for some tasks (such as a build pipeline). It is no frills, but bulletproof.

#6

figured the first responders would be the TA heavy hitters.

Thanks for the input guys :slight_smile:

@Theo “You could maybe write your app as a plugin using the C# api and control Maya from there, passing args on the command line to a headless maya instance”

K: Yea, was thinking this may be the fallback, I’m not so keen on this as it relies of a level of obfuscation and maintaining the libraries would be a bit more challenging.

though it seems like it may be necessary. sadly. :frowning:

@btribble: “You can load foundation.dll…”
K: Sadly, I was unable to load foundation.dll, I received the following: “Please make sure the file is accessible, and that it is a valid assembly or COM component”

Also, I was planning on having this run seperately, and interface with Maya for content on the Users current working file, as needed. So, maybe… a functional copy isnt ideal, as i need the current application instance. :frowning:

Currently, I have this working with photoshop through its COM interface, but with Maya…I think I may be reaching too far on this one.

Is there a way to do this through another language? maybe python? C++?

#7

You want to look at the commandPort stuff. This will work as advertised, though if you want to run multiple copies of Maya concurrently, things get more complex.

#8

Oh Beautiful. These are great options. :slight_smile:

I have a few options now, plugin[args], commandport and mayaBatch files, and all 3 look promising and expandable.

Thanks very much for taking the time to reply.

:slight_smile:

#9

Hey Just wanted to say thanks again,
Also to update I ended up going with a local PC WCF server/client setup. Between a C# Maya plugin and my External C# Tool, to send string commands back and forth.
Works good so far, and seemed like a decent solution.

Cheers,
-Karl

#10

Don’t forget to use Maya’s threading stuff on the far end.

http://download.autodesk.com/global/docs/maya2014/en_us/index.html?url=files/Python_Python_and_threading.htm,topicNumber=d30e815215