Hey all -

In my HDA, I'm trying to access the vertex colors of a mesh created in Unity. The mesh is connected into my HDA via a slot in the Input Nodes.

The mesh is successfully imported into the HDA. However, when I try to access vertex colors, I get this error:

“isReadable is false; Read/Write must be enabled in import settings”

What does this refer to? There aren't any import settings on the mesh in Unity.

Anyone know how to fix this?

So the generated mesh in Unity is by default set to not readable, for performance friendly reasons. To make them readable, you will need to set a detail attribute named “unity_mesh_readable” with a value of 1.

seelan
So the generated mesh in Unity is by default set to not readable, for performance friendly reasons. To make them readable, you will need to set a detail attribute named “unity_mesh_readable” with a value of 1.

This is a mesh I'm creating with Pro Builder – not Houdini. The mesh is an input to my HDA.

Where would I set the unity_mesh_readable attribute? Do you mean set it in the HDA? Or somewhere in Unity upstream of the HDA?

seelan
So the generated mesh in Unity is by default set to not readable, for performance friendly reasons. To make them readable, you will need to set a detail attribute named “unity_mesh_readable” with a value of 1.

Ok, so this answers the opposite question: this is how to set the readable flag for a mesh generated by an HDA.

I'm trying to read a Unity mesh into my HDA, and I'm getting errors about vertex colors being unreadable. I've read all the documentation I can find, and this isn't mentioned anywhere.

The use case is this: I have some Unity meshes which, for whatever reason, have vertex color data. I want to use this data in my HDA.

Is this supported?

You have to make the mesh data readable via whatever generated it, so in this case, it would be ProBuilder.

Maybe look for something like this in the mesh import settings:
https://answers.unity.com/storage/attachments/149976-capture.png [answers.unity.com]

seelan
You have to make the mesh data readable via whatever generated it, so in this case, it would be ProBuilder.

Maybe look for something like this in the mesh import settings:
https://answers.unity.com/storage/attachments/149976-capture.png [answers.unity.com]

Ok, I did this, and I'm still getting errors.

Are you certain this is supported? I have a reproducible test case. Happy to send you some screenshots and/or files, but… have you actually tried this?

Sure, submit a bug with necessary files to support@sidefx.com. Thank you.

seelan
Sure, submit a bug with necessary files to support@sidefx.com. Thank you.

Ok, I've emailed support@sidefx.com. Take a look when you get a chance!

For reference, here's what I said:

Files are here:https://drive.google.com/drive/folders/1IHeD2VOB6oglRM1Ud7B5K9q1CkQSYtxU?usp=sharing [drive.google.com]

I've included a video which shows the bug happening. (might still be uploading…)

To reproduce:
1) Set up a Unity project with Houdini Engine
2) Load the annabd_attr_test_out HDA.  This will create a grid with random colors.  Attach a vertex color shader to see them.
3) Bake the HDA output
4) Load  the annabd_attr_test_in HDA5) Import the baked mesh from step (3) into annabd_attr_test_in using Input Nodes/Add Selection
6) Console displays errors

@seelan were you able to take a look at this?

I've found that I am able to read some attributes off the input mesh in an HDA. But, I still get the error messages. Even if they're incorrect, it's a problem – I can't tell the difference between real and fake error messages.

Hi, sorry for the delay. I will look into this very soon and get back to you. I have received your bug report as well.