Houdini custom attributes to vertex color map?

[Mokiki]

Does anybody know the correct workflow to get an alembic with custom attributes out of Houdini and into vray proxy + the vertex color map in 3ds max?
I am trying it with a two different color attributes (same type) but I can only render one of them and even that one isn't really recognized by the vertex map.
Meaning it doesn't show any channel names but it renders one of them in map channel 2.

Would appreciate any pointers in the right direction.

[psanitra]

Use Alembic ROP, and just list your attributes there. Are your attributes showing as map channels in 3d max when you right click on the vray proxy, object properties, user defined tab?

you should see something like:

MapChannel:0 =
MapChannel:1 = grownarea
MapChannel:2 = Cd
MapChannel:3 = localzscale

You should see something like this if you exported your attributes as vectors attributes.
If you exported as float attribues, you will see something like:


MapChannel:0 =
MapChannel:1 = Cd
MapChannel:2 = r_grownarea; g_localzscale;

So it matters how you export it, for me it`s easier to use vector so each attribute gets its own channel, easier to read/work with.

Hope it helps!

[Mokiki]

I was using the Alembic ROP and listed my attributes in the point attributes text box. Also tried the default *.
First of all big thanks for the response Peter.

When I checked the user defined tab was empty.
What I did to create my attributes was a simple attributecreate with $CR for the value and putting that out as float or vector both yielded the same result.
If it isn't too much to ask could you maybe do a quick example file on how you usually export with just 1 or 2 attributes?
Sadly I won't be able to do any tests until Monday since I am not in front of my workstation and you can't export with the non-commercial version.

[gandhics]

3dsMax abc importer can read any arbitrary channel written by Houdini.
I'll come as UV.

If you want to bring in 3 float data. Combine as a vector and use each channel in 3dsMax.

[Mokiki]

Decided to do quick stop at the office and test this again. Now I am pretty sure this is bugged.
When I import an object with different attributes in a fresh new scene I see the different channels under the user defined tab and the vertex map.
When I change the name of the attributes in houdini and export the alembic under the same or new name and import it again the user defined tab shows no change or is empty.
If I create a new vray proxy object and reimport my alembic file the user defined tab and the vertex map stay empty.
Now when I reboot max and import the alembic into the proxy again I get the updated channels. Using reset max doesn't do anything either. I have to restart 3ds max to see any change.

Using 3ds max 2017 and vray 3.5 (official release not beta)