Problems with points representing objects in dopimport

[ophamletsen]

Hi,

I`m currently trying to use the "Create Points to Represent Objects" import style in a Dop Import node.

I thought that would give me center points for each rbd object, but so far I have not been able to make that work.

What I`m trying to achieve is to copy some geometry onto these points, which inherits the translation, rotation etc., from the corresponding rbd piece

I included a simple hip fille showing my problem. The points seem to be moving all over the place, and certainly not representing the objects.

Any help on this problem would be greatly appreciated

points_to_represent_objects.hipnc

[anim]

they do, just keep in mind that pieces that you are sending to DOP have offset 6 units in Y from pivot (and plus a little bit per piece) so even though the imported points do not represent centroids of piece geometries they correspond to what was send to DOPs so when you copy the same pieces to them it will match

but they as well contain pivot attribute which contains offset from pivot to computed center of mass so you should have no problem to get the centroid points if you wish

[ophamletsen]

Thanks anim, i got it working!

However I`m strugglin when trying to do it on a slightly larger scale.

Im trying to copy some geometry onto the fractured pieces, but I don`t get whats going on.

I had some more help here, but the closest we got to what I want is what you can see in the attached hip file. Everything works fine until it collides...

points_to_represent_objects_v2.hipnc

[anim]

well, this is what I meant when I said that you can offset points by pivot attribute (you need to do it in local space of the dop object)

this way you can get centroids of your objects as that seems to be what you are aiming for (but if you want to replace the pieces with higher res pieces geo or something similar, you can avoid computing centroids)

points_to_represent_objects_v2_fix.hipnc

[ophamletsen]

Thank you very much anim!

[ranxerox]

Thank you very much anim!

 

 can anybody confirm that this setup works/doesn't work in H13 (H13.0.198.21). It looks fine in Houdini 12.5.533,  but very wrong in H13.0.198.21 (haven't tried other builds yet).

 

 thanks

 

 -G

[sadhu]

turn off transform using template point attribute on the copy node where you are copying spheres on points and it is working.

[ranxerox]

 Thanks Sadhu,  unfortunately turning that off means the spheres aren't rotated properly anymore.  I wonder what changed between Houdini versions ?

 

 -G

 

 

turn off transform using template point attribute on the copy node where you are copying spheres on points and it is working.

[oatz]

 Thanks Sadhu,  unfortunately turning that off means the spheres aren't rotated properly anymore.  I wonder what changed between Houdini versions ?

 

 -G

This is driving me nuts. Was this ever solved?

 

EDIT: I got around this by deleting the pivot attribute coming out of the dopimport.

Edited August 19, 2014 by oatz

[ranxerox]

This is driving me nuts. Was this ever solved?

 

 I think the best way to do this now is to use "transform_pieces".   I've attached an example using the file from above as a base.

 

 -G

points_to_represent_objects_transform_pieces.hipnc

[anim]

 can anybody confirm that this setup works/doesn't work in H13 (H13.0.198.21). It looks fine in Houdini 12.5.533,  but very wrong in H13.0.198.21 (haven't tried other builds yet).

 

 thanks

 

 -G

to make that scene work in H13 you'd need to check Center At Pivot on the DOP Import as that was not in H12.5, done

on top of that

while Center At Pivot Checked, you can just delete pivot attrib as oatz mentioned so it's not used by Copy SOP and that will work as well

and of course Transform pieces is build for similar purpose so it will work as well, however it's still dependent on Center At Pivot checked, but that's default in H13

[ranxerox]

to make that scene work in H13 you'd need to check Center At Pivot on the DOP Import as that was not in H12.5, done

on top of that

while Center At Pivot Checked, you can just delete pivot attrib as oatz mentioned so it's not used by Copy SOP and that will work as well

and of course Transform pieces is build for similar purpose so it will work as well, however it's still dependent on Center At Pivot checked, but that's default in H13

 

 thanks for the clarification.  I've pretty much moved on to using transform pices whenever I can for speed, but it's good to know this difference between h12 and h13.

 

 cheers

 

 -G