Hi,

I'm reading in a bgeo cache with a hda that just contains a file sop.
Engine correctly loads the particles and maps the per point attributes to dynamic per particle attributes in maya.

However, if i try and query these attributes using
particle -id X -attribute Cd -q particleShape
or
particle -order X -attribute Cd -q particleShape
i get the error:
// Error: line 1: Could not find specified particle. Please check the value passed to -id or -order. //
but the particle does exist

If i do the same thing with a maya created nparticle system i get the value of that attribute from the corresponding point.

Is there a difference in the attributes the houdini engine creates and the ones maya creates?

The reason i am asking is that i can't get arnold to pick up any of my custom attributes (floats and vectors) from houdini engine nparticles (apart from rgbPP)
It does work with maya nparticles.

Anyone have experience with this?

Some common attributes that exist in both Houdini and Maya are mapped to their equivalent. For example, Houdini's Cd would be mapped to Maya's rgbPP. Other custom attributes should be carried across to Maya with their original name.

Take a look at the attached Maya and asset file.

Which version of the Maya plugin are you using? There may have been bugs that were fixed. I think the last bug fix related to particle attribute was 14.0.304, make sure you're using at least that.

thanks for your reply.
it seems that is you try the expression on any of the ‘internally mapped’ attributes then you receive that error, but if you try it on other custom attributes it works fine.

By chance i was only trying it with attributes like opacity, pscale (all of the mapped ones). So i was getting the error every time.

So in summary, it works as it should, and they can be exported to arnold just as any maya particle attribute. But maybe you can make a note of this error?

Thanks

Looks like I can kind of reproduce the issue after all. But in my case, “particle -id” errors out, but “particle -order” does work.

“-id” doesn't work probably because the particles don't contain an “id” attribute. I've made a change so that the plugin will generate the “id” attribute if the points don't already have it. But “-order” should have worked though. The changes should be in tomorrow's build (14.0.411).