How to center text on slanted triangular face?

Question

I am trying to model my own 20 sided die and to add the numbers on each face. I am having trouble getting them centered on each triangular face. Any suggestions on how to achieve this?

Answer 1

Here is the script to do that

import bpy 
import bmesh


def addText(text, location, rotation, mat, fact = .2, extrude = .005): 
    myFont = bpy.data.curves.new(type="FONT", name="myFont")
    fontOb = bpy.data.objects.new(fontObjName, myFont)
    fontOb.data.body = text
    bpy.context.scene.objects.link(fontOb)
    bpy.context.scene.update()
    fontOb.select = True
    bpy.context.scene.objects.active = fontOb
    fontOb.dimensions = (fontOb.dimensions[0] * fact, fontOb.dimensions[1] * fact, fontOb.dimensions[2] * fact)
    fontOb.data.extrude = extrude
    bpy.ops.object.origin_set(type='ORIGIN_GEOMETRY')
    fontOb.location = location
    fontOb.rotation_mode = 'QUATERNION'
    fontOb.active_material = mat
    fontOb.rotation_quaternion = rotation.to_track_quat('Z','Y')
    fontOb.select = False
    return fontOb


def labelObjFaces(obj, mat):    
    bpy.ops.object.mode_set(mode = 'EDIT', toggle = False)
    bm = bmesh.from_edit_mesh(obj.data).copy()
    bpy.ops.object.mode_set(mode = 'OBJECT', toggle = False)
    for f in bm.faces:
        fontOb = addText(str(f.index), f.calc_center_median(), f.normal, mat)
        fontOb.parent = obj

fontObjName = "__fontObj123" 
matName = '__labelMat123'
deleteOldFs = [fObj for fObj in bpy.data.objects if fObj.name.startswith(fontObjName)]

#clean-up
for delF in deleteOldFs:
    bpy.data.objects.remove(delF)
if(matName in bpy.data.materials):
    bpy.data.materials.remove(bpy.data.materials[matName])

mat = bpy.data.materials.new(matName)
mat.diffuse_color = (0.3731134057044983, 0.59569658041000366, 0.3000000715255737)

labelObjFaces(bpy.context.object, mat)

To execute the script.

• open the blend file that has your object
• switch to script view
• click new button
• paste the code
• deselect all the objects (move the mouse to 3d view and press a)
• select the object on which you want to put the labels by right clicking on it
• click the 'Run Script' button

Answer 2

UV mapping.

As an alternative to using 20 font objects, I propose this can also be done with a UV map and an image editor. Here is a very quick run down on how this can be achieved.

For a 20 sided dice like above can add a single division icosphere. Check generate UVs

Here is the generated UV map. For whatever reason drawing on this map comes out A about T, so select all and scale -1 in X to mirror. A S X - 1

Choose the menu Image Editor > UV > Export Layout to File choose a filename, then open in your fave image editor.

Add the numbers to the triangles.