Group primitives by normal direction [SOLVED]

[cudarsjanis]

Hi,

This is probably easy, but I can`t wrap my head around it today.

How could I get primitive group where primitives from extruded mesh are grouped by color and N direction from another geo.

I could just do attribute transfer and group by color, but then I get edges of extruded geo as well sometimes. I need just the faces with N direction same as not fractured geo.

I need just the outer shell of extruded geo. But I want to control the group with color from one sided surface.

Will try again tomorrow, but maybe someone knows quick way of doing that?

 

Cheers

Janis

group_faces.hip

[vicvvsh]

Hi,

there are output groups in a poly extrude sop, you can use "extrudeFront" primitive group in your case.

group_faces_01.hipnc

[cudarsjanis]

9 hours ago, vicvvsh said:

Hi,

there are output groups in a poly extrude sop, you can use "extrudeFront" primitive group in your case.

group_faces_01.hipnc

Spasibo Viktor,

That would be easy then yes, but this is just an example scene. I have alembic geo imported, with no groups predefined. So that is why I thought maybe best way to goup outer shell is by matching normals.

[flcc]

16 hours ago, cudarsjanis said:

I could just do attribute transfer and group by color, but then I get edges of extruded geo as well sometimes.

Is that what you want?

In the Attribute Promote set the promotion methode to minimum.
In attributeTransfert decrease distance threshold a little bit

 

group_faces F.hip

[cudarsjanis]

34 minutes ago, flcc said:

Is that what you want?

In the Attribute Promote set the promotion methode to minimum.
In attributeTransfert decrease distance threshold a little bit

 

group_faces F.hip

Thanks for the reply,

Not really, the whole idea with grouping using normals would be to get only shell be in the group. normals for those small primitives by the edges are not aligning with normals from the mesh that I`m using to transfer color.

[cudarsjanis]

To make it more clear I would like to group faces from sphere nr 2, whose normals are facing same direction as closet point from sphere 1. 

 

[cudarsjanis]

Ok, I got it

Just had to use dot product of 2 vectors

group_faces_dot_product.hip