PolyBevel on Point Issue

[Houdini7]

Hello dear odforce community,

 

I am new here and happy to be part of this nice community. Like you all I like houdini. In the last months I have learned many things and I think it is really an awesome program. 

I was designing with PolyBevel and come along one issue, it is really strange. What I try is to round an edge at a point with PolyBevel.

Sometimes it does the correct thing and sometimes not. I will start with an example where it works:

1. Create a grid with enough columns and rows

2. Select one point on one edge and move it in some direction

3. PolyBevel the point which was moved to round the grid edge

Everything works as expected, the edge is rounded at the point.

 

Now the same procedure with a sphere.

1. Create a sphere

2. Remove one half of it (select prim and blast)

3. Select a point on the emerging edge and move it in one direction

4. PolyBevel the selected point

This is an unexpected behavoiur. The prims are split and the edge is not rounded.

 

Is this a bug? What can I do to prevent this behaviour. I want to round the edge at the point. Is there another mehtod to do it ? The "Split Over all Incident Edges" Option does not work like it should !!

What I already tried:

1. I have used a Clean SOP

2. I have tried to convert the sphere bevore PolyBevel to Polygon/Quadliterals etc.

3. I have tried to move all points (Transfer Node). Have read there is a bug, so the movement could solve it ?!

Nothing did change the behaviour, have you any hint ? Thanks in advance.

Edited July 3, 2017 by Houdini7

[Noobini]

no need to use a sphere...if you read the help on the "Split Over All Incident Edges"...it works on non-flat edges...so in my scene you see there are 2 same protrusions...except one is raised so that it's non-flat, the same poly bevel is applied and you get 2 different results because of the non-flatness...(put Display flag on the polybevel1_defect to see the effect)

If you turn on "Split Over All Incident Edges"...then they would both look the same..but of course, this is not what you want.

So in the polybevel2, since you said you want to round off the edges I've promoted the points in question and then beveled out the edges....had you said you wanted to round out the points...I would not have found a workaround...you can disable Split Over All Incident Edges if you don't like the extra 'mesh'...

Bevelnonflat.hipnc

[Houdini7]

Thank you very much Noobini. Indeed it seems always when it is not flat, it breaks it. Can you eloberate a little bit your solution? You promote the points to edges. What attributes are promoted, and why is this a solution to the problem ? Thanks in advance.

Unfortunately the extra faces are not so nice, but at least you can dissolve the edges and it looks clean.

Perhaps there is some other solution?

[Houdini7]

Perhaps a more general question. How do you round edges in houdini ? What is the best approach ? If this would be a curve one could use the Refine SOP but if it is an edge is there something similar ?

[Houdini7]

15 hours ago, Noobini said:

no need to use a sphere...if you read the help on the "Split Over All Incident Edges"...it works on non-flat edges...so in my scene you see there are 2 same protrusions...except one is raised so that it's non-flat, the same poly bevel is applied and you get 2 different results because of the non-flatness...(put Display flag on the polybevel1_defect to see the effect)

If you turn on "Split Over All Incident Edges"...then they would both look the same..but of course, this is not what you want.

So in the polybevel2, since you said you want to round off the edges I've promoted the points in question and then beveled out the edges....had you said you wanted to round out the points...I would not have found a workaround...you can disable Split Over All Incident Edges if you don't like the extra 'mesh'...

Bevelnonflat.hipnc

I have tried your approach and it works. As I understand the result would be the same like selecting only one edge (not the boundary edges) and beveling that. So the Group Promote SOP "only" converts the selection from the selected point to the three edges of the point. The PolyBevel then bevels only one edge, and ignores the two boundary edges (therefore the warning in the node).

Edited July 4, 2017 by Houdini7

[Noobini]

definitely not a 'solution'...just a quick and dirty workaround..
The reason I promoted the selected points to edges was I thought you'd most likely to select some point that looks 'sharp' and you want to round it out..it's more logical than thinking..well I'm going to select an edge..then round it out..that's all...and if there was a workaround on points..I would have tried to work with that...but no there wasn't so I had no choice but to go to edge mode.

The GroupPromote simply promotes group membership, so if point A belongs to groupX, if I GroupPromote point to edge then the edges that point A belongs to are now in GroupX (or whatever name you choose)...same if I promote point to primitive...what I learnt was this...I've always assumed 'promote' goes 'up'...ie..point->edge->primitive->detail...but no....it can go other way too...ie. you can 'promote' primitive->point too...

[Houdini7]

@Noobini: Yes, this makes sense. My solution to round an edge is now to do a planar on neighbor points and then PolyBevel.