materials_per_char.py

import bpy
from bpy.props import IntProperty

"""
Usage, run the script to add character properies to bpy.types.Object
The UI appears in 3dview Tools, as MISC. You'll get a direct mapping between
character and material index (based on material_slots).

You can set keyframes using the sliders, and you can render / playback the
material updates because of the added frame_change event handler.


"""

def charmat_update(self, context):
    # this is used for the visual feedback when adjusting sliders
    # and this is also called by the framechange event to update the
    # material per character (unless there's a neater way to do this)

    b = context.object.textmat_addon
    for i, character in enumerate(bpy.data.objects['Text'].data.body_format):
        tval = getattr(b, "char_" + str(i))
        if tval >= len(context.object.material_slots):
            tval = len(context.object.material_slots) - 1
        character.material_index = tval

def text_updater(scene):
    charmat_update('uchhhh', bpy.context)


class TextualProperties(bpy.types.PropertyGroup):
    for i in range(80):
        exec("char_{0} = IntProperty(min=0, max=90, update=charmat_update)".format(i))

class CustomPanel(bpy.types.Panel):
    """A Custom Panel in the Viewport Toolbar"""
    bl_label = "Generate"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'TOOLS'

    @classmethod
    def poll(self, context):
        if context.object and context.object.type == 'FONT':
            if context.object.mode == 'OBJECT':
                return True

    def draw(self, context):
        layout = self.layout
        col = layout.column()
        body = context.object.data.body
        props_addon = context.object.textmat_addon
                
        for i in range(len(body)):
            row = col.row()
            row.label(body[i])
            row.prop(props_addon, 'char_' + str(i), text="")
        

def register():
    bpy.utils.register_module(__name__)
    bpy.types.Object.textmat_addon = bpy.props.PointerProperty(type=TextualProperties)
    
    handler = bpy.app.handlers.frame_change_post
    if not (text_updater in handler):
        handler.append(text_updater)

def unregister():
    bpy.utils.unregister_module(__name__)
    del bpy.types.Object.textmat_addon

    handler = bpy.app.handlers.frame_change_post
    for func in reversed(handler):
        if func.__name__ == 'text_updater':
            handler.remove(func)


if __name__ == "__main__":
    register()