[Plugin] triangulateFaces.rb v1.2 20101120

TIG

Strange, I can't find it anywhere in my long long plugin list .
Maybe it clashes with some other plugin? (I do have WxSU installed which caused me trouble with other plugins in the past).
By the way, I am on SU6 Pro.

If you have 2.1 open it in a text editor and read the last bit it should define the menu...

CPhillips

I finally figured out how to triangulate any face without the side effect of filling holes.

def triangulateFace(face)
    mesh=face.mesh(1)
    faces=mesh.polygons
    verts=mesh.points
    uvs=mesh.uvs(true)
    outmesh = Geom;;PolygonMesh.new
    faces.each{|f|
        outmesh.add_polygon(verts[f[0].abs-1],verts[f[1].abs-1],verts[f[2].abs-1])
    }
    ents=Sketchup.active_model.active_entities
    mat=face.material
    face.erase!
    grp = ents.add_group
    grp.entities.add_faces_from_mesh(outmesh)
    grp.entities.each{|e|
        if(e.class==Sketchup;;Edge)
            e.smooth=false
            e.soft=false            
        elsif(e.class==Sketchup;;Face && mat!=nil)
               #handle materials and uvs.
            uva=verts.index(e.vertices[0].position)
            uvb=verts.index(e.vertices[1].position)
            uvc=verts.index(e.vertices[2].position)
            e.material=mat
            e.position_material(mat,[verts[uva],uvs[uva],verts[uvb],uvs[uvb],verts[uvc],uvs[uvc]],true)
        end
    }
    grp.explode
end

Coronel

Could you please clarify for a 3D newie the purpose of triangulation in this case?
Does it means the model will be correct or will work better or is merely a way of get more detail?

TIG

@coronel said:

Could you please clarify for a 3D newie the purpose of triangulation in this case?
Does it means the model will be correct or will work better or is merely a way of get more detail?

If you have a mesh that's rectangular it won't deform consistently. If you triangulate the faces they will... etc.

CPhillips

I needed the triangulation to prepare a model for export.

Thanks for incorporating it into your script TIG! Why is it that back facing UV's didn't work?

CPhillips

@tig said:

@cphillips said:

I needed the triangulation to prepare a model for export.

Thanks for incorporating it into your script TIG! Why is it that back facing UV's didn't work?

There is only a method to 'place material textures on a face' - and that assumes a 'front_face' - there's no 'back_face' method...

Do you mean position_material? It takes a bool for front or back material

http://code.google.com/apis/sketchup/docs/ourdoc/face.html#position_material

ideas_arte

Thanx really useful!

where download?

Jim

@ideas_arte said:

where download?

That's a valid question; it is not clear which version is the latest, and it is harder than necessary to locate the download.

The download is about 5 posts before this one.

TIG

@cphillips said:

I needed the triangulation to prepare a model for export.

Thanks for incorporating it into your script TIG! Why is it that back facing UV's didn't work?

There is only a method to 'position material textures on a face' - and that assumes a 'front_face' - there's no 'back_face' method ? ...

TIG

@cphillips said:

@tig said:

@cphillips said:

I needed the triangulation to prepare a model for export.

Thanks for incorporating it into your script TIG! Why is it that back facing UV's didn't work?

There is only a method to 'place material textures on a face' - and that assumes a 'front_face' - there's no 'back_face' method...

Do you mean position_material? It takes a bool for front or back material

http://code.google.com/apis/sketchup/docs/ourdoc/face.html#position_material

Duh! I'll adjust the code and re-post...

TIG

There's something afoot... What I posted before worked - on keeping the front face texture mapping but not on the back_face... Now when I try it it fails to map both faces ? Any ideas - CPhillips's idea worked fine in tests but now seems to fail...

CPhillips

Post the code and I'll have a look. It might be the face.mesh(1). I think you need to use a different number when you want back uv's as well.

honoluludesktop

Hi TIG, Any way to convert this kind of mesh into its component triangles?

Drapery05.skp

TIG

@honoluludesktop said:

Hi TIG, Any way to convert this kind of mesh into its component triangles?

I wrote an example script a few weeks ago to do something like this... http://forums.sketchucation.com/viewtopic.php?p=186068#p186068

honoluludesktop

TIG, Thanks for the link, it works. Now I can make small edits to the (mesh?).

jeff hammond

@tig said:

Result: it triangulates a face... front Texture UVs are kept.

hey TIG,

if i run the script on this sphere, the UVs go haywire.
am i misunderstanding or misusing the script?
thanks

[edit] ok, wait.. i just read the rest of the thread and i guess this hasn't been sorted out ?

sorry about the size.. i guess i could of used a smaller texture

TIG

@unknownuser said:

@tig said:

Result: it triangulates a face... front Texture UVs are kept.

hey TIG,

if i run the script on this sphere, the UVs go haywire.
am i misunderstanding or misusing the script?
thanks

[edit] ok, wait.. i just read the rest of the thread and i guess this hasn't been sorted out ?

It's broken... the UV mapping was CJP's but it still needs fixing...

jeff hammond

@tig said:

It's broken... the UV mapping was CJP's but it still needs fixing...

ah, ok..
too bad

[fwiw - i can manually triangulate the sphere using and everything turns out ok.. i guess this script is doing something other than just drawing lines to cut quads in half?]

TIG

@unknownuser said:

@tig said:

It's broken... the UV mapping was CJP's but it still needs fixing...

ah, ok..
too bad

[fwiw - i can manually triangulate the sphere using and everything turns out ok.. i guess this script is doing something other than just drawing lines to cut quads in half?]

It triangulates the quads and tries to fix the UV mapping - obviously very badly !!!! CJP help!

TIG

See this new script just for selected quad faces - it keeps UV mapping etc...
http://forums.sketchucation.com/viewtopic.php?p=201025#p201025