Vertex refusing to weld or collapse

[jacobwallace]

Hey all.

 

I am working with a model which had been imported from Sketchup into 3dsMax. having exported the mesh in FBX format each corner or wall junction were the incidence of two vertex meet are attached in Sketchup are overlapped in 3ds max. I would like for the vertices to weld together however max refuses to do this using these methods

 

- unlinking geometry/relinkgeometry/group/Editpoly/Vertex/Weld

 

- unlinking geometry/relinkgeometry/group/Editpoly/Vertex/Target Weld

 

- unlinking geometry/relinkgeometry/group/Editpoly/Vertex/collapse/Weld

 

-Editpoly/Edge(delete offecnding poly)/Bridge

 

I am trying to weld two single sided polygon planes together. my only other option is to retrofit new geometry in place deleting the original parts which do not weld together, should anyone have other solutions please share.

 

The problem is visible in the final render i.e Normal maps having no continuity along profiles.

 

 

Many thanks guys/girls

 

 

-------------------------------------------------Solution---------------------------------------------------

 

I have to credit a tutorial for the fix here

 

When rendering geometry in Vray with displacement maps switched on and have gaps in corners or bordering edges try the following.

 

-Turn off displacement map inside material

-Select the Mesh you want to fix with the material applied and add a VraydisplacementMod from the Modifier list

-Copy an instance of your displacement map over to Texmap under Common params in the VraydisplacementMod

 

---------------------------------------(Inside VraydisplacmentMod)-------------------------------------------

-Check the box "Keep continuity" under 3D mapping/subdivision

-Change the Edge threshold to factor 0.01

 

I hope this helps anyone else who has had the same issue and had 12 hours out of workflow

Edited December 8, 2016 by jacobwallace

[Nicolai Bongard]

Sketchup is notorius for creating doublesided geometry. It may appear to be onesided, but it may be worth to double check. Sometimes verteces will not weld as the resulting geometry would not make sense. When having your verteces selected, on the top (i guess) on the edit poly menu thingy there is a text telling you how many verteces are selected. If there are more than two, you may allready have found the problem. I would suggest trying to create a box with one corner where your verteces are supposed to be welded, just for reference later. Then you select your verteces and see how many are selected (where you would only expect two i guess). Then you split the verteces and select one at a time and trag them out/away to see how the geometry truly is shaped, and then you can do the cleanup from there. When the culprit has been found and eliminated, weld your geometry and snap it back to the corner of the box you created as reference.

 

The problem i believe you are experiencing is two edges meeting akwardly. To try to explain: Out from a vertex there can be many edges, but an edge can only be between two faces. So for example if you think of this angle shape as extruded upwards, and seen from the top, this; > would be the two foursided polygons/quads/faces forming the corner of a wall. If you then have two of these, like this; >

 

This is from what i understand most likely the problem you are facing, and if so the only way to get around it is to clean up your geometry. I may be wrong, but you should try to clean it up like i described. I would be suprised if that does not fix your problem.

[jacobwallace]

Thank you Nicolai I used your method to trouble-shoot the problem, having identified the number of actual vertices to be welded to a single point to confirm whether there were multiple faces.

 

The polies complied to weld when target welded with a box in the same element but did not solve the issue, having turned displacement mapping off with only bump and diffuse map materials switched on, a seamless edge would appear. Conversely the noticeable gap appeared when displacement was switched on again.

 

To further rule out the mesh topology issue I rebuilt the faces retrofitting the new ones in place with a single poly then applied the material with displacement map toggled and the same noticeable gap appeared in render.

 

I am now unsure whether displacement maps can span multiple faces in a single poly at different angles from the camera without noticeable gap.