kicking ass with debug shading


You can use kick to render with debug shading. Here’s the flags to use:

  • -is to ignore the shaders assigned to the shapes
    When you ignore shaders, a default utility shader is used to render the scene.
  • -sm sets the shade mode ( ndoteye lambert flat ambocc plastic metal)
  • -cm sets the color mode (color ng ns n bary uv u v dpdu dpdv p prims uniformid wire polywire obj edgelength floatgrid reflectline bad_uvs nlights id bumpdiff pixelerror)

Here’s some examples that show how to kick with different types of debug shading (I’ve used the Arnold Render View debug shading modes for these examples)

 

Debug shading kick flags
Basic: disable all shaders in the scene, switching to a gray ‘ndoteye’ shader; a very fast shading mode.
kick -is

or

kick -is -sm notdoteye
Lighting: renders the scene with a white lambert shader
kick -is -sm lambert
Occlusion: use ambient occlusion shading
kick -is -sm ambocc
Wireframe: displays geometry as a wireframe
 kick -is -cm polywire

or

kick -is -sm ndoteye -cm polywire
Normal: visualizes the normal vector (between 0 and 1, in tangent space)
 kick -is -sm flat -cm n
UV: displays the coordinates of the primary UV set (red=U, green=V)
 kick -is -sm flat -cm uv
Primitive ID: displays random colors based on the per-primitive (triangle, curve) index
 kick -is -sm flat -cm prims
Barycentric: displays intra-primitive parametric coordinates (barycentric for triangles, parametric length, and width for curve segments)
 kick -is -sm flat -cm bary
Object: displays random colors based on the per-object ID
kick -is -sm flat -cm obj

Using an operator to override parameters in an ass file


Arnold 5.1 adds operators, which among other things, allow you to override parameters in ass files loaded by procedural nodes.

Here’s a quick example using the brand new MtoA 3.0

I exported some particles from Softimage, loaded them into Maya with an aiStandin (aka an Arnold procedural), and then used a set_parameter operator to scale the radius by 0.5

Note that I connect my operator by setting the Target Operator in the Render Settings.
set_parameter_radius
I can chain two set_parameter operators together, to set the mode and then scale the radius:
set_parameter_mode_radius

[mtoa] Arnold batch rendering flags


MtoA defines a lot of batch render flags for Arnold. For example, here’s how to set the Arnold log verbosity and enable file logging:

render -s 2 -e 2 ^
-r arnold ^
-ai:lve 2 ^
-ai:ltf true ^
-ai:lfn C:/Users/blairs/Downloads/render.log ^
D:\Projects\maya\Support\scenes\example.ma

First,  to use the Arnold batch render flags, you need to use the Maya -r flag to specify that the renderer is arnold (otherwise, you’ll get an “Invalid flag” error).

Then you can use the Arnold batch render flags:

  • ai:lve sets the log verbosity level
  • ai:ltf enables file logging (Log To File)
  • ai:lfn is the log file name. I used forward slashes; I could also have used backslashes and put quotation marks around the log file name.

[MAXtoA] Rendering XGen in 3ds Max


 

You can export an ASS file from Maya (with the XGen primitives) and then use an Arnold Procedural to load the ASS file into 3ds Max.

You need to add these two folders to the system environment variable Path:
  • C:\Program Files\Autodesk\Maya2018\plug-ins\xgen\bin
  • C:\Program Files\Autodesk\Maya2018\bin

For example, you can copy this:

C:\Program Files\Autodesk\Maya2018\plug-ins\xgen\bin;C:\Program Files\Autodesk\Maya2018\bin;

and paste it at the beginning of the current Path:

windows_sys_env_var

Restart 3ds Max after you do this.

Then add the MtoA procedurals folder to the Plugin Search Path:

maxtoa_plugin_search_path

 

[MtoA] cross-platform volume file names


The Arnold volume node uses the texture search path, so you don’t have to use an absolute path in the volume filename.

volume_texture_searchpath

So if you need to set up a Maya scene so that the OpenVDB volumes work on any platform, you could put an environment variable in the Texture Search Path

volume_env_var

Just note that support for volume filenames is still a little … rough. You can’t enter an absolute path in the aiVolume Filename box, then enter a texture search path, and expect MtoA to automatically export a relative path. That still needs to be implemented.

For now, here’s what to do:

  • When you first create the volume, load the vdb file and leave the full absolute path in the aiVolume Filename box.
  • Select the grids and set the other volume parameters.
  • Then set the texture search path and strip off the path from the volume file name (leaving just the file name).
  • Now the environment variable will control where Arnold looks for the vdb file.

The Arnold volume node also support environment variables, so you could do this:

volume_env_var_in_filename

But again, once you put the environment variable into the Filename, the path won’t be resolved inside Maya (but it will work when you render).

compiled against non-compatible Arnold


If you see something like this:

[Arnold]: MAXtoA_Shaders.dll was compiled against non-compatible Arnold 5.0.2.1

it usually means you have an older Arnold trying to load something compiled with  a newer Arnold. There’s two common reasons for this happening:

  • The system PATH includes the location of the older Arnold, so the older Arnold is loaded instead of the Arnold version included with the plugin.
  • The plugin install is messed up, and has the wrong Arnold version in it.