blendercam/scripts/addons/cam/slice.py

"""BlenderCAM 'slice.py' © 2021 Alain Pelletier

Very simple slicing for 3D meshes, useful for plywood cutting.
Completely rewritten April 2021.
"""

import bpy
from bpy.props import (
    BoolProperty,
    FloatProperty,
)
from bpy.types import PropertyGroup

from . import (
    constants,
    utils,
)


def slicing2d(ob, height):  # April 2020 Alain Pelletier
    # let's slice things
    bpy.ops.object.transform_apply(location=True, rotation=False, scale=False)
    bpy.ops.object.mode_set(mode='EDIT')  # force edit mode
    bpy.ops.mesh.select_all(action='SELECT')  # select all vertices
    # actual slicing here
    bpy.ops.mesh.bisect(plane_co=(0.0, 0.0, height), plane_no=(0.0, 0.0, 1.0), use_fill=True, clear_inner=True,
                        clear_outer=True)
    # slicing done
    bpy.ops.object.mode_set(mode='OBJECT')  # force object mode
    # bring all the slices to 0 level and reset location transform
    ob.location[2] = -1 * height
    bpy.ops.object.transform_apply(location=True, rotation=False, scale=False)
    bpy.ops.object.convert(target='CURVE')  # convert it to curve
    if bpy.context.active_object.type != 'CURVE':  # conversion failed because mesh was empty so delete mesh
        bpy.ops.object.delete(use_global=False, confirm=False)
        return False
    bpy.ops.object.select_all(action='DESELECT')  # deselect everything
    return True


def slicing3d(ob, start, end):  # April 2020 Alain Pelletier
    # let's slice things
    bpy.ops.object.transform_apply(location=True, rotation=False, scale=False)
    bpy.ops.object.mode_set(mode='EDIT')  # force edit mode
    bpy.ops.mesh.select_all(action='SELECT')  # select all vertices
    # actual slicing here
    bpy.ops.mesh.bisect(plane_co=(0.0, 0.0, start), plane_no=(0.0, 0.0, 1.0), use_fill=False, clear_inner=True,
                        clear_outer=False)
    bpy.ops.mesh.select_all(action='SELECT')  # select all vertices which
    bpy.ops.mesh.bisect(plane_co=(0.0, 0.0, end), plane_no=(0.0, 0.0, 1.0), use_fill=True, clear_inner=False,
                        clear_outer=True)
    # slicing done
    bpy.ops.object.mode_set(mode='OBJECT')  # force object mode
    # bring all the slices to 0 level and reset location transform
    ob.location[2] = -1 * start
    bpy.ops.object.transform_apply(location=True, rotation=False, scale=False)

    bpy.ops.object.select_all(action='DESELECT')  # deselect everything
    return True


def sliceObject(ob):  # April 2020 Alain Pelletier
    # get variables from menu
    thickness = bpy.context.scene.cam_slice.slice_distance
    slice3d = bpy.context.scene.cam_slice.slice_3d
    indexes = bpy.context.scene.cam_slice.indexes
    above0 = bpy.context.scene.cam_slice.slice_above0
    # setup the collections
    scollection = bpy.data.collections.new("Slices")
    bpy.context.scene.collection.children.link(scollection)
    if indexes:
        tcollection = bpy.data.collections.new("Text")
        bpy.context.scene.collection.children.link(tcollection)

    bpy.ops.object.mode_set(mode='OBJECT')  # force object mode
    minx, miny, minz, maxx, maxy, maxz = utils.getBoundsWorldspace([ob])

    start_height = minz
    if above0 and minz < 0:
        start_height = 0

    # calculate amount of layers needed
    layeramt = 1 + int((maxz - start_height) // thickness)

    for layer in range(layeramt):
        height = round(layer * thickness, 6)  # height of current layer
        t = str(layer) + "-" + str(height * 1000)
        slicename = "slice_" + t  # name for the current slice
        tslicename = "t_" + t  # name for the current slice text
        height += start_height
        print(slicename)

        ob.select_set(True)  # select object to be sliced
        bpy.context.view_layer.objects.active = ob  # make object to be sliced active
        bpy.ops.object.duplicate()  # make a copy of object to be sliced
        bpy.context.view_layer.objects.active.name = slicename  # change the name of object

        # attribute active object to obslice
        obslice = bpy.context.view_layer.objects.active
        scollection.objects.link(obslice)  # link obslice to scollecton
        if slice3d:
            # slice 3d at desired height and stop at desired height
            slicesuccess = slicing3d(obslice, height, height + thickness)
        else:
            # slice object at desired height
            slicesuccess = slicing2d(obslice, height)

        if indexes and slicesuccess:
            # text objects
            bpy.ops.object.text_add()  # new text object
            textob = bpy.context.active_object
            textob.data.size = 0.006  # change size of object
            textob.data.body = t  # text content
            textob.location = (0, 0, 0)  # text location
            textob.name = tslicename  # change the name of object
            bpy.ops.object.select_all(action='DESELECT')  # deselect everything
            tcollection.objects.link(textob)  # add to text collection
            textob.parent = obslice  # make textob child of obslice

    # select all slices
    for obj in bpy.data.collections['Slices'].all_objects:
        obj.select_set(True)


class SliceObjectsSettings(PropertyGroup):
    """Stores All Data for Machines"""

    slice_distance: FloatProperty(
        name="Slicing Distance",
        description="Slices distance in z, should be most often "
        "thickness of plywood sheet.",
        min=0.001,
        max=10,
        default=0.005,
        precision=constants.PRECISION,
        unit="LENGTH",
    )
    slice_above0: BoolProperty(
        name="Slice Above 0",
        description="only slice model above 0",
        default=False,
    )
    slice_3d: BoolProperty(
        name="3D Slice",
        description="For 3D carving",
        default=False,
    )
    indexes: BoolProperty(
        name="Add Indexes",
        description="Adds index text of layer + index",
        default=True,
    )