Arnold Standard Surface not shading my alembic model when I import.

[Big_Rig]

Thank you, to anyone who can help me make any headway with this situation. I am using Maya 2019 student version (not sure if that matters) with Windows 10, and I have exported an animation I have to an alembic file. Great! I then import my model back into the scene through the alembic cache menu, and when I assign the Arnold shader, or any shader that is more complicated than a simple color, it refuses to shade my model.

I created a test scene to show what I am talking about. It is a poly cube that has been augmented and animated with some joints, it is only for this test. I have tried the exports as all of the alembics. This scene is a GPU Cache export, with a simple Arnold Standard Surface shader with a simple ramp in the color channel. That's it. It was the easiest way to get the point across.

I have watched others do this endlessly online, no one else seems to have an issue with shading after import and I have read through the docs, and everything says as long as you import it back into the scene file, when you assign the shader it should work and shade your model.

What is it I am doing wrong in my alembic cache import workflow. I tried to attach a scene file, but it wouldn't allow me to post without removing it first, so I only submitted an image, but you get the idea. Thank you in advance.

[Big_Rig]

I did just come across this at Arnold answers. crossing fingers, hoping it works.

You will need to make sure "Export All shading Groups" is enabled in Render Settings -> System

[Big_Rig]

Nope! Not that simple. Still white generic Lambert import, and no shade when I apply my scenes Arnold shader. 😞

[Big_Rig]

trying to upload scene file.

[mspeer]

Hi!

The alembic file is missing in your ZIP file.

[Big_Rig]

Thank you, once again for handling my request for assistance. I have re-saved the information inside the zip file. And posted an updated image. Thank you.

[Big_Rig]

The names are cleaner in this one. 🙂

[mspeer]

Hi!

Sorry, but there is only the Maya scene (.mb), but not the alembic file (.abc).

[Big_Rig · Accepted solution]

After more experimentation. I discovered it is a UV issue. The image I attached is not perfect, the uv's do not match. There is a uv issue with alembic when importing. Which is confusing to me, because the feature in the alembic export panel allows you to click, UV write.

I only had this success once I did a UV projection onto the alembic. I was also playing with the merged alembic file options. Which this is confusing because in the root scene which holds the scene data, if it is to replace the original object how then would it know to transfer the uv data, if it doesn't do this when you write out the UV's? Now that I know I need to re-uv my model I have to get back to making forward progress with my scene. Thank you.

[Big_Rig]

Here it is. I apologize for the delay.

[Big_Rig · Accepted solution]

I meant apply a cylindrical map, not a projection.

[Big_Rig · Accepted solution]

The key is to transfer attributes after importing. First, select the original mesh and the newly imported alembic mesh, then go into the modeling menu set and select under mesh use the transfer attributes option with component on.

[mspeer]

Hi!

@Big_Rig 

Based on the last provided data, the issue is a complete different one.

1. Your alembic file already has the exact same UVs as the object on the Maya scene, so the export worked fine.

2. When you want to use the alembic file as "normal" object with UVs inside Maya

DO NOT use GPU Cache -> ...,

use Alembic Cache -> ... instead.

[Big_Rig]

I updated the file. I even sent a lonely alembic by itself for review. I had to figure this out on my own, really. Which is not obvious, or easy if you have no experience with this matter in a pipeline. I spent the greater part of a day, if not the whole day not standing on the shoulders of giants with all of the answers and teching this out by myself.

Which in a way I am thankful for, but I am certain we might never have arrived at this conclusion, so I apologize, if there was extraneous information included in the file. If I give you more, then it is me looking for answers. An alembic cache, a GPU cache (that one I provided because of the color-per-vertex feature baked in.) I was having to guess which cache would accept a shader the easiest,  and through experimentation I figured out a solution. In effect, I needed help. That's why I am here on a help board.

I also, appreciate you for assisting me whenever. I know it is not easy dealing with a million questions a day, always having to have the right answers, and keeping your cool overall. Thank you for caring. Working remotely is it's own lonely void in the art world, and having someone you can hit up from time to time, when in doubt, is a blessing. Take care.