# Combining Boxes

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Its been a while but now i am a REAL houdini operator (i have a real job).

So on to my question... how would you combine boxes together and remove the faces that are on top of each other.

I am making a chopper for a dops job and i want to lay out small boxes on to points. Group them into random groups of 1 to 12 boxes and then take those clumps of cubes and remove primitives that are on the inside then fuse the lot for each chunk. this is done for each chunk then noise is applyed.

In writing this out i find i have a major clue alredy i will have primitives that are on top of each other so i need to group any primitives that have the same position as any other prim. then delete them.

so any ideas on that one?

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Can I see an image > of what you mean. ! plus congrats on the job !

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If you are using H9 have a look at the "Remove Overlapping Faces" SOP.

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If you are using H9 have a look at the "Remove Overlapping Faces" SOP.

This is funny! I've just told my self: "It wouldn't be very difficult to write such a tool in python SOP..."

Then I checked a tool you advised and... realized that this is a python based tool with a nice and simple solution. Although not terrible fast for big meshes I think.

I only wonder if:

- calculating a centroid of primitive in python is faster/slower then getting it from Houdini via expression or even geometry attribute.

- the same issue for calculating vectors comparison

- also sorting procedure could be slow in python

sy.

Edited by SYmek
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I did a quick test, created a box, removed all except top and bottom faces, scale it down on Y axis to make them overlap. Could someone explain me why the tool doesn't work in that case? Both faces have the same centroid, and are exactly the same, isn't it enough?

kuba

N?

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N?

This node doesn't care about Normals. It takes into account only prims vertices position.

Hey Kuba,

this has something to do with the fact the doing it you way you're trying to remove *all* prims in geo. I don't have a time right now to debug this code but maybe you just found a bug (or a limitation more).

took a box and copied it over its self with its height distance (I put one box onto another). Than I applied our sop and it works as expected. Previously I used it on more then a 1000-polygon geometry with overlapping prims and it worked fine also!

cheers,

sy.

Edited by SYmek

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