autoTransformBlender.py

"""
autoRotate
==========

(Blender edition -- also available for Maya)

Align the selected edge to the world X axis of the scene by rotating the whole mesh.

Usage
-----

Select exactly one edge, then run the script.

License
-------

Copyright (c) 2017 Elie Michel -- ATI (Universite Paris 8)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
"""

bl_info = {
    "name": "AutoTransform",
    "author": "Elie Michel",
    "version": (1, 0),
    "blender": (2, 79, 0),
    "location": "View3D > Mesh > AutoTransform",
    "description": "Tools for automatic edge alignment",
    "warning": "",
    "wiki_url": "",
    "category": "Mesh",
    }


import bpy
from mathutils import Vector, Matrix

########################## Utility functions ##########################

def getPoints(context):
    obj = context.object
    # Get editmode changes
    obj.update_from_editmode()
    mesh = obj.data

    selected_edges = [e for e in mesh.edges if e.select]

    if len(selected_edges) != 1:
        raise TypeError('You must select exactly one edge')

    # Get the  position of the vertices of the selected edge
    edge = selected_edges[0]
    p = [mesh.vertices[v].co for v in edge.vertices]
    p = [obj.matrix_world * u for u in p]
    return p

def applyAlignmentMatrix(context, p, mat):
    obj = context.object
    c = (p[0] + p[1]) / 2.0

    # Translation matrices, in order to rotate around the center of the edge instead of the origin point
    t1 = Matrix.Translation(c)
    t2 = Matrix.Translation(-c)

    obj.matrix_world = t1 * mat * t2 * obj.matrix_world

########################## Operators ##########################

class AlignEdgeOp(bpy.types.Operator):
    @classmethod
    def poll(cls, context):
        return bpy.context.active_object.mode == 'EDIT' and bpy.context.object.type == 'MESH'
    

class AlignEdgeToXOperator(AlignEdgeOp, bpy.types.Operator):
    """Align the selected edge to the world X axis of
    the scene by rotating the whole mesh."""
    bl_idname = "transform.align_edge_to_x"
    bl_label = "Align Edge to X Axis"

    def execute(self, context):
        p = getPoints(context)

        # Reconstruct rotation matrix from the target X vector
        z = Vector((0, 0, 1))
        x = (p[1] - p[0]).normalized()
        y = z.cross(x).normalized()
        z = x.cross(y).normalized()
        mat = Matrix((x, y, z)).to_4x4()

        applyAlignmentMatrix(context, p, mat)
        return {'FINISHED'}

class AlignEdgeToYOperator(AlignEdgeOp, bpy.types.Operator):
    """Align the selected edge to the world Y axis of
    the scene by rotating the whole mesh."""
    bl_idname = "transform.align_edge_to_y"
    bl_label = "Align Edge to Y Axis"

    def execute(self, context):
        p = getPoints(context)

        # Reconstruct rotation matrix from the target X vector
        z = Vector((0, 0, 1))
        y = (p[1] - p[0]).normalized()
        x = y.cross(z).normalized()
        z = x.cross(y).normalized()
        mat = Matrix((x, y, z)).to_4x4()
        
        applyAlignmentMatrix(context, p, mat)
        return {'FINISHED'}

class AlignEdgeToZOperator(AlignEdgeOp, bpy.types.Operator):
    """Align the selected edge to the world Z axis of
    the scene by rotating the whole mesh.
    Try to rotate around X as much as possible"""
    bl_idname = "transform.align_edge_to_z"
    bl_label = "Align Edge to Z Axis"

    def execute(self, context):
        p = getPoints(context)

        # Reconstruct rotation matrix from the target X vector
        x = Vector((1, 0, 0))
        z = (p[1] - p[0]).normalized()
        y = z.cross(x).normalized()
        x = y.cross(z).normalized()
        mat = Matrix((x, y, z)).to_4x4()
        
        applyAlignmentMatrix(context, p, mat)
        return {'FINISHED'}


########################## Panel ##########################

class AutoRotatePanel(bpy.types.Panel):
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'TOOLS'
    bl_category = "Tools"
    bl_context = "mesh_edit"
    bl_label = "Auto Transform"

    def draw(self, context):
        layout = self.layout

        col = layout.column(align=True)
        col.operator("transform.align_edge_to_x")
        col.operator("transform.align_edge_to_y")
        col.operator("transform.align_edge_to_z")

########################## Registering ##########################


def register():
    bpy.utils.register_class(AlignEdgeToXOperator)
    bpy.utils.register_class(AlignEdgeToYOperator)
    bpy.utils.register_class(AlignEdgeToZOperator)
    bpy.utils.register_class(AutoRotatePanel)

def unregister():
    bpy.utils.unregister_class(AlignEdgeToXOperator)
    bpy.utils.unregister_class(AlignEdgeToYOperator)
    bpy.utils.unregister_class(AlignEdgeToZOperator)
    bpy.utils.unregister_class(AutoRotatePanel)

if __name__ == "__main__":
    register()