Group By Bounding Intersection Problem With Multiple Objects

[pclaes]

Hi,

I've ran into a little problem with point selection in a group node.

I have two hollow spheres (or tori) growing over time, each sphere selects a bunch of points on a grid as they grow through a group (by bounding object) node. The problem occurs when two spheres intersect: the points that are inside of the first AND inside of the second are not added to the group.

I want those points to be selected as well, is there a work around?

pt_selecter_02.hip

[MIguel P]

Hi,

I've ran into a little problem with point selection in a group node.

I have two hollow spheres (or tori) growing over time, each sphere selects a bunch of points on a grid as they grow through a group (by bounding object) node. The problem occurs when two spheres intersect: the points that are inside of the first AND inside of the second are not added to the group.

I want those points to be selected as well, is there a work around?

Yes, this is a problem with the Group. Try with metaballs or generating the iso offset from the bounding objects and using the result to group.

But if you are using spheres, you can use the Attribute Tansfer to transfer an attribute using a radius and then group the points using an expression in the Group.

[Lukich]

ALternatively you can pipe your spheres through a cookie sop that only lives the area of intersection and use that are to group points.

[pclaes]

Thanks for the replies,

the cookie sop gave me a bit messy results using just the spheres.

But when I used it in combination with the metaballs and the iso surface offset it worked.

I do realise that the resulting geometry is a lot heavier to calculate, but luckely the particles don't need to live very long.

thanks again!

pt_selecter_03.hip

[bhbilbao]

Same problem here. when mergin more than 2 objects sharing the same space "Group by bounding objects(points only)" , one of then doesnt work.(the intersected one)

The convert meta+ cookie doesnt work for me.
Using Isooffset works , but the bounding mess is being deformed a lot .., not precise.

Need help if anyone knows another method or trick.
Thanks.
 

[Noobini]

8 hours ago, bhbilbao said:

Same problem here. when mergin more than 2 objects sharing the same space "Group by bounding objects(points only)" , one of then doesnt work.(the intersected one)

just thinking aloud, the merging of objects.....isn't that Boolean ? Why not just Boolean the objects as Union ?

[bhbilbao]

Yes , Noobini, boolean/cookie works easy as you have only two objects A + B plugged into A and B slots of the cookie node.
The problem is than I have more than 10 objects all merged before (with a merge node).
Is a house with windows cuts,...in the walls there are modules like balcony or chimeney..etc, these addons are all merged to do a delete/blast points on the walls... but there is some type of conflict.. some points are not deleted when one of the object intersect with another.
In the image attached the blue ones are balcony and the white one chimeney, merged before and atached to group node. The white one doesnt work when shares same space as the blue ones.

[bhbilbao]

..and this is with the isooffset ; works but same as pclaes user said.."geometry is a lot heavier to calculate". Also the original edges are displaced..deformed using small sampling divs.