mia_material Bug

[dagon1978]

Create a polygon object. Create a mia_material and assign it to only one or some of the faces. Direct illumination will stop working on those faces. In some cases objects that are already or will be assigned with this material will also stop working.

Based on my experience and messages from other users I’m aware that MR has some problems with material per face assignment in certain situations during batch rendering, but I’m posting this as a more severe from this line of problems ahd none of this is mentioned in the MR restrictions section of the Release notes.

light linking > 2

ciau ;)

Mat

[Emil3d]

Thanks Mat:thumbsup:. I think Autodesk should hire you to write properly the Maya documentation.:)

[Puppet|]

It's not mia_material bug, but it's mayatomr bug. Same problem with all mr (custom) shaders.
Maya don't link lights to custom mr shaders if shader assigned to faces, but not to object.

[rygoody]

I've been using light linking mode 3 to avoid this. It works just fine.

[Emil3d]

Thanks for the clarification Puppet. The bad thing is that after I selected all mia_materials and typed 2 for mode in the channel box all my material swatches in Hypershade are now black. So I have to do that only before each rendering. A little bit annoying but what can I do. Sigh.

Edit: Oh rygoody, mode 3 brings back the swatches, cool.

Just curious how many modes and what's behind each number? Can't find anything about this in the help. A pointer wouild be nice.

[Emil3d]

Well after spending another couple of hours of head scratching and testing finally I’ve reached some conclusions that cleared some mystery about all this.

Mode 0 and 1 renders the illumination of the shader from all lights except places where the shader was assigned per faces. If there are lights connected to the shader as displayed in the Lights section of the Attribute Editor, only the illumination from these lights will be rendered including per face shader assignment.

Mode 2 renders the illumination from all lights including per face shader assignment except the lights connected to the shader (listed in the Lights section) This causes all shader swatches in Hypershade and Attribute Editor to become black.

Mode 3 renders all illumination regardless whether shader was assigned per object or face and regardless whether the lights are connected or not.

Most of this makes some sense as a shader based light linking except the behavior of the per shader assignment which seems to me as a result of a poor MR integration.

Also mode 3 appears to be the best choice for a default but unfortunately they’ve chosen mode 0 causing some unnecessary confusion and extra work for the unsuspected users. LOL
And finally they could have just put a few easy to find words in the help about how these modes work so that we don’t waste time with figuring out puzzles.

All this was sent to Autodesk and I encourage others to send it too. More people asking the better. It is easy; from the main menu in Maya go to Help > Report a Problem and/or Suggest a Feature. PLE users are welcome to do so too.


Have a nice day:)

[djx]

Thanks Emil3d, Mat and rygoody, this thread would have saved me a few hours of head scratching & hair pulling last week - those black swatches were most anoying. I never thought of trying mode=3. This is good to know.:thumbsup:

-- David

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