Hi everybody,

I am a new user in Houdini and have a problem with the welding of two Polygons together.
1- first I make a primitive cube (Type : Polygon)
2- I delete half of it and duplicate the other half.
3- I merge them all and then I use “fuse” to weld the vertices between them.
4- The vertices don't weld and still there is a seam between them.

In the other hand, If I change the Type to “Polygon mesh” and do the same process I have a nice welding and there is no problem.

I would be appreciated if anybody tell me how I can fix this problem and what is the difference between Poly mesh ,mesh , and polygon?

Thanks

First make sure that the Fuse SOP is actually consolidiating those points on the seam.
I usually use the MMB on the SOP before the Fuse and note the point count then MMB on the Fuse to see if there is a difference. If there isn't, I know that no points were consolidated.
If there is a difference in the point numbers and the Fuse is consolidating some points, I will then turn on point numbers in the viewport. You should only see a single point number on your seam.

If the seam isn't welded, increase the fuse distance until they do consolidate. The default value of 0.001 is very small. I usually turn on point numbers then increase the distance until the points obviously fuse. Not too high or you will start to fuse other parts of the model. Increasing this value to rediculous values is lots of fun as you watch your model get crushed in to a distorted badly shading mess. If you find this happening, you have to select a region of points and either make a group and use that or put that string of points in to the Group field. Reselct the fuse (back quote key) works great for this.


If the points are welded, then I suspect that you have a shading issue with adjacent reversed primitive normals. A bad thing in general. You want your primitive normals always pointing outwards and adjacent polys all facing the same way.
If you turn on your primitive normals, you will see some pointing inward and some outward. A result of the negative scale in the Duplicate SOP.
You can fix this with either a Reverse SOP and selecting those primitives or us a procedural way with the Facet SOP and togging on Orient Polygons. Note that Orient Polygons requires that all adjacent points be consolidated. In other words, the first Fuse step needs to work in order to procedurally orient your primitve normals correctly.

If you do orient your primitive normals all in the same direction but they point inward (will screw up DOP sims, Cookie Operations and more), you need to use a Reverse SOP to reverse all the primitives.

Hi there,

My mistake was instead of using consolidate option I chose snap.Thank you very much for you help.

Do you think there is a need to do a “snap consolidate” as the option currently doesn't exist. You have to first snap, then follow up with another fuse to consolidate.

Hi there,

Thank you for the fast respond.I really appreciate it.

jeff
Do you think there is a need to do a “snap consolidate” as the option currently doesn't exist. You have to first snap, then follow up with another fuse to consolidate.

In addition to this it would be really nice if the consolidate worked on point clouds. (Snap works fine) The current work around is use an Add SOP and create a primitive that runs from 0-$N, consolidate, then use another Add SOP to blast away the primitive.

Submitted both RFE's.

Hi there,

Please see the image.It is a very simple character that I made with polygons and when I consolidated the Vertices,I got the soft shape with no seam.Thank you for the help again.