Alembic Mesh - how to read channels e.g. velocity

User avatar
FlorianK
Posts: 238
Joined: Fri Jun 11, 2010 9:56 am
Location: Cologne, Germany

Alembic Mesh - how to read channels e.g. velocity

Post by FlorianK » Thu Aug 08, 2013 5:02 pm

I exported a mesh sequence to Houdini and imported it there as ABC sequence. In Realfow's Export Central, I checked all the channels (velocity, vorticity etc.) and now I was wondering howto access those from inside Houdini.

Inside the Alembicarchive, there is a Mesh Shape SOP Alembic Surface node, having that node selected in Details View I cannot see any attributes. Any idea what I might be missing?

ben.fox@framestore.com
Posts: 41
Joined: Thu Aug 29, 2013 4:12 pm

Re: Alembic Mesh - how to read channels e.g. velocity

Post by ben.fox@framestore.com » Fri Aug 30, 2013 2:38 pm

I thought I would post to try to help a little in this ghost town.
From Export Central it seems that the only mesh file format that supports any attributes is the .md format...but I have no idea how to import that format into houdini or anything else for that matter.
One workaround could be to import the mesh sequence and also the particle sequence you used to generate the mesh. The particles have the attributes which you could transfer to your mesh...slow and not ideal...but could do the trick in a pinch.
Hopefully that helps.
All the best.
~Ben

User avatar
Hector
Site Admin
Posts: 15
Joined: Thu Jun 10, 2010 11:55 am

Re: Alembic Mesh - how to read channels e.g. velocity

Post by Hector » Mon Sep 02, 2013 2:51 pm

Hi

Maybe this can help you

Regard
You do not have the required permissions to view the files attached to this post.
Hector Artal
RealFlow | Cinema4D developer
Next Limit Technologies

User avatar
atena
Site Admin
Posts: 112
Joined: Fri Jun 04, 2010 1:25 pm

Re: Alembic Mesh - how to read channels e.g. velocity

Post by atena » Mon Sep 02, 2013 3:16 pm

ben.fox@framestore.com wrote:I thought I would post to try to help a little in this ghost town.
From Export Central it seems that the only mesh file format that supports any attributes is the .md format...but I have no idea how to import that format into houdini or anything else for that matter.
One workaround could be to import the mesh sequence and also the particle sequence you used to generate the mesh. The particles have the attributes which you could transfer to your mesh...slow and not ideal...but could do the trick in a pinch.
Hopefully that helps.
All the best.
~Ben
No, you are wrong. You can and must use ABC format as it supports different attributes.
Angel Tena
Head of RealFlow Technology
Next Limit Technologies

mcermak
Posts: 1
Joined: Thu Jun 10, 2010 9:24 pm
Contact:

Re: Alembic Mesh - how to read channels e.g. velocity

Post by mcermak » Mon Sep 02, 2013 4:04 pm

Hey Hector,
Marcelo Here.
How are you?
Good stuff for houdini and I will try to make it work in houdini.
Now do you have anything for maya (MR)?
Let me know
M

User avatar
FlorianK
Posts: 238
Joined: Fri Jun 11, 2010 9:56 am
Location: Cologne, Germany

Re: Alembic Mesh - how to read channels e.g. velocity

Post by FlorianK » Tue Sep 03, 2013 11:13 am

Thank you hector. The Parameter node was what I was looking for!!!

Marcelo, maybe this helps for RFRK with dental ray:

Image

Image

(in some browsers, you will have to open the images in a new tab)

ben.fox@framestore.com
Posts: 41
Joined: Thu Aug 29, 2013 4:12 pm

Re: Alembic Mesh - how to read channels e.g. velocity

Post by ben.fox@framestore.com » Tue Sep 03, 2013 2:33 pm

atena wrote: No, you are wrong. You can and must use ABC format as it supports different attributes.
Wow, kind of a harsh response.
I am very familiar with working with ABC files and sending additional attributes between Maya <> Houdini.
Would be great to get a little more info on the right workflow of doing this from Realflow.
Here is a pic of my 2013 Export Central window.
export.jpg
As you can see, ABC format doesn't have any of the attribute options that md offers.
I tried exporting an abc sequence and didn't have any luck bringing any attributes into Houdini.
I still only get velocity and uv when I import an alembic sequence...even with all those md attributes checked in Export Central.
Unfortunately the help topic on this subject doesn't say anything about additional attributes either:

Mesh sequence (.abc)

"ABC stands for the new Alembic format. Please be aware that some older software versions do not have any import or export filters for Alembic files."

Anyway, looks like there were some good suggestions made. Hopefully someone can post some more specifics on the issue of getting all those additional attributes.
All the best.
~Ben

###Edit###
Just started doing some Hybrido meshes and now I see the options...why don't those export options exist for the regular particle meshes?
I didn't realize that FlorianK was talking about Hybrido Meshes...or that there was a difference between the two. I have only done regular particle meshes.
Would be really nice to have the same options.
You do not have the required permissions to view the files attached to this post.

User avatar
atena
Site Admin
Posts: 112
Joined: Fri Jun 04, 2010 1:25 pm

Re: Alembic Mesh - how to read channels e.g. velocity

Post by atena » Tue Sep 03, 2013 5:21 pm

Ben, I'm so sorry if it sounded like a harsh answer. It wasn't my intention, I just want to go quickly over other things I was doing. Sorry about that.

In my answer I assumed also Hybrido and of course I was wrong doing that assumption. In the case of a Particle mesh you are totally right and we should add the list of attributes as we do for the MD file.

We will add that ASAP, bear with us.

Cheers.
Angel Tena
Head of RealFlow Technology
Next Limit Technologies

ben.fox@framestore.com
Posts: 41
Joined: Thu Aug 29, 2013 4:12 pm

Re: Alembic Mesh - how to read channels e.g. velocity

Post by ben.fox@framestore.com » Tue Sep 03, 2013 10:52 pm

Its all good atena, I assumed as much.
That would be a great addition!
I will keep a look out for it.
Very very cool!

izo
Posts: 53
Joined: Wed Sep 19, 2012 2:42 pm

Re: Alembic Mesh - how to read channels e.g. velocity

Post by izo » Mon Apr 29, 2019 6:51 pm

@atena is there any update on this?
How can one get channels like velocity or vorticity exported with any type of mesh? I had this working with rfrk previously but am starting to become a little hopeless here as it just doesn't seem to work.

Post Reply