Mesh Check


I’m working on a new addon to check my meshes.

The goal is to see Ngons and tri in the viewport when working on objects.

Right now it uses vertex paint to show faces, a friend made me a little code for that and I finished to make an addon and use it when working in edit mode to clean my mesh.
I implemented a part of CoDEmanX’s script “” to select Ngons and tri.

It’s a wip, and I hope it is possible to have an autorefresh in real time when the show faces is activated.
I’m not as good to do this, so if someone can help me, don’t hesitate !

#  This program is free software; you can redistribute it and/or
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#  of the License, or (at your option) any later version.
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#  along with this program; if not, write to the Free Software Foundation,
#  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

bl_info = {
    "name": "Mesh Check",
    "author": "Clarkx, Cédric Lepiller, CoDEmanX",
    "version": (0, 0, 1),
    "blender": (2, 74, 0),
    "description": "Custom Menu to show faces, tri, Ngons on the mesh",
    "category": "3D View",}

import bpy
from bpy.props import EnumProperty

bpy.types.Scene.show_faces = bpy.props.BoolProperty(default=False)

##CoDEmanX's code to select Ngons, tri  
class DATA_OP_facetype_select(bpy.types.Operator):
    """Select all faces of a certain type"""
    bl_idname = "data.facetype_select"
    bl_label = "Select by face type"
    bl_options = {'REGISTER', 'UNDO'}

    face_type = EnumProperty(name="Select faces:",
                             items = (("3","Triangles","Faces made up of 3 vertices"),
                                      ("4","Quads","Faces made up of 4 vertices"),
                                      ("5","Ngons","Faces made up of 5 and more vertices")),
                             default = "5")
    def poll(cls, context):
        return context.active_object is not None and context.active_object.type == 'MESH'

    def execute(self, context):

        context.tool_settings.mesh_select_mode=(False, False, True)

        if self.face_type == "3":
            bpy.ops.mesh.select_face_by_sides(number=3, type='EQUAL')
        elif self.face_type == "4":
            bpy.ops.mesh.select_face_by_sides(number=4, type='EQUAL')
            bpy.ops.mesh.select_face_by_sides(number=4, type='GREATER')

        return {'FINISHED'}

#Clarkx's code to show faces, Ngons and Tris with the vertex paint mode.
class Show_Faces(bpy.types.Operator):
    bl_idname = "object.showfaces"
    bl_label = "Show Faces"
    bl_description = "Show Tri, Ngons and Faces"
    bl_options = {"REGISTER"}
    def poll(cls, context):
        return True
    def execute(self, context):
        scn = context.scene
        bpy.context.scene.render.engine = 'BLENDER_RENDER'

        # Objet actif
        mesh =

        # Creation d'un nouveau vertex color
        vertex_colors =

        # Pour chaque polygon de l'object
        for poly in mesh.polygons:
            # Recupération du nombre de vertices
            nbvert = len(poly.vertices)
            # Pour chaque vertex on assigne une couleur :
            for loop_index in poly.loop_indices:

                # Rouge : Si le polygon a trois vertices
                if nbvert == 3: # Triangle
                    vertex_colors[loop_index].color =  [0.603, 0.500, 0.117]

                # Vert : Si le polygon a quatre vertices
                if nbvert == 4: # Quad
                    vertex_colors[loop_index].color =  [0.5, 0.5, 0.5]

                # Bleu : Si le polygon a un nombre de vertices > 4
                if nbvert > 4: # Ngons
                    vertex_colors[loop_index].color =  [0.8, 0.146, 0.146]
        bpy.context.space_data.viewport_shade = 'TEXTURED'  
        scn.show_faces = True
        return {"FINISHED"}    

class Remove_Vertex_Color(bpy.types.Operator):
    bl_idname = "object.removevertexcolor"
    bl_label = "Remove Vertex Color"
    bl_description = "Remove Vertex Color to clean the List"
    bl_options = {"REGISTER"}
    def poll(cls, context):
        return True
    def execute(self, context):
        scn = context.scene
        bpy.context.space_data.viewport_shade = 'SOLID'
        scn.show_faces = False

        return {"FINISHED"} 

class Show_Faces_Menu(bpy.types.Panel):
    bl_idname = "view3D.show_faces_menu"
    bl_label = "Mesh Check"
    bl_space_type = "VIEW_3D"
    bl_region_type = "TOOLS"
    bl_category = "Mesh Check"
    def poll(self, context):          
        return context.active_object is not None and context.active_object.type == 'MESH'
    def draw(self, context):
        layout = self.layout
        scn = context.scene
        if scn.show_faces == False:
            layout.operator("object.showfaces", text='Show Faces', icon='COLOR')
            row = layout.row(align=True)
            row.operator("object.removevertexcolor", text='Hide Faces', icon='GHOST_ENABLED') 
            row.operator("object.showfaces", text='Refresh', icon='FILE_REFRESH')  
        #code by CoDEmanX to select Ngons, tri   
        ob = context.active_object
        info_str = ""
        tris = quads = ngons = 0

        for p in
            count = p.loop_total
            if count == 3:
                tris += 1
            elif count == 4:
                quads += 1
                ngons += 1

        info_str = "  Ngons: %i  Quads: %i  Tris: %i" % (ngons, quads, tris)
        col = layout.column()
        col.label(info_str, icon='MESH_DATA')

        col = layout.column()
        col.label("Select faces by type:")

        row = layout.row(align=True)
        row.operator("data.facetype_select", text="Ngons").face_type = "5"
        row.operator("data.facetype_select", text="Quads").face_type = "4"
        row.operator("data.facetype_select", text="Tris").face_type = "3"   

def register():

def unregister():
if __name__ == "__main__":

It’s a wip, and I hope it will be possible to have an autorefresh in real time when the show faces is activated.
I’m not as good to do this, so if someone can help me, don’t hesitate !

The best will be to have a button in the Npanel>shading to show those Ngons and tri in real time ^^

Hope you like it and thx to Clarkx and CoDEmanX !


this is similar to meshlint addon i hope mesh lint cant be real-time and add color for better visual feedback

may be you can join force with meshlint creator and make a more robust addon

you did it again :slight_smile:

Thx ^^

I use Meshlint every day, but honesly I only use the select ngons.

I think we can make a great tool for cleanning meshes, I’m a newbie in conding, so if someone want participate, it will be great ^^

Hello there
You can use Fedge tool from 1D_Scripts, for searching different mesh checks in object or edit modes

There is already a select mode for this; you can do this with Select Menu > Select Face by Sides > Set number of vertices in the panel and choose comparison method (greater , less than, equal)

The problem is not to select faces, but to update automatically the vertex paint ^^

Sorry ; my bad. :smiley:

Wazou strikes again!

Great idea, elegant resolve.
It’d be awesome to have a live update, but even as is I find this very useful. I prefer this to mesh lint, way better from my point of view.

You’re spot on with so many things you’re doing. If I could imagine a dream roadmap for blender, it’d be BI hiring you as a consultant! It’s evident that all the stuff you do is from a user perspective, and one who has extensive experience from many platforms. Here’s to hopes someone from the BI recognizes what you bring to the table.

Thanks on sharing all the hard work!

Thx OrAngE, but I’m not as good as you think ^^

Update of Mesh Check By pistiwique !

It’s now in realtime, works well with Automatcap and keep the shading.

1 Like

Great Work!..Thanks for sharing!

indeed great work very useful for the retopo process.
Big thanks to pistiwique (whoever he is ) and to you @pitiwazou

Much appreciated, thanks.

New BGL version soon available and modified by pistiwique !

No more shaders ^^

We wrote a Fedge function (from 1D_Scripts tools), that locates tris/ngons, loose verts, loose edges, non-manifold edges and tiny-area polygons in object and edit modes!



It selects by step, ignoring hidden and evaluets by hitting space and entering “FFF” in search line

Hello guys.
This is the last release of the mesh check addon. The code is based on the Matpi’s addon Borderline.
You can download MechCheck here:

1 Like

Very nice, thanks for sharing!

I’m wondering if the colors and face opacity options wouldn’t be better in the Add-on settings instead of the Display tab, which is already quite cluttered? I assume one wouldn’t want to change these settings often.