initial commit

README.md

+# Robotarm Simulator
+
+Blender scene and export script for creating animations for the Dofbot robotic arm.
+
+## Todo
+
+- [ ] Add/subtract correct offsets to angles to match with Dofbot angles
+- [ ] Add constraints to angles
+- [ ] Fix mirrored part of claw
+

exporter.py

+import math
+import json
+
+import bpy
+from bpy_extras.io_utils import ExportHelper
+from bpy.props import StringProperty
+from bpy.types import Operator
+
+
+def print(data):
+    for window in bpy.context.window_manager.windows:
+        screen = window.screen
+        for area in screen.areas:
+            if area.type == 'CONSOLE':
+                override = {'window': window, 'screen': screen, 'area': area}
+                bpy.ops.console.scrollback_append(override, text=str(data), type="OUTPUT")
+
+
+# Alternative way to get animation data
+# Takes the keyframes instead of going through frame by frame
+def get_animaiton_data(servo_object):
+    for fcurve in servo_object.animation_data.action.fcurves:
+        for keyframe_point in fcurve.keyframe_points:
+            yield keyframe_point.co
+
+
+SERVO_NAMES = ['bottom_rotation', 'joint_1', 'joint_2', 'joint_3', 'claw_grip', 'claw_rotation']
+
+
+def get_servo_objects():
+    return [bpy.data.objects[servo_name] for servo_name in SERVO_NAMES]
+
+
+def get_moving_angle(servo_name, rot_deg):
+    if servo_name == 'bottom_rotation':
+        return rot_deg.z
+    if servo_name == 'joint_1':
+        return rot_deg.y
+    if servo_name == 'joint_2':
+        return rot_deg.y
+    if servo_name == 'joint_3':
+        return rot_deg.y
+    if servo_name == 'claw_rotation':
+        return rot_deg.z
+    if servo_name == 'claw_grip':
+        return rot_deg.x
+
+
+def frame2time(frame):
+    fps = bpy.context.scene.render.fps
+    return int(frame/fps*1000)
+
+
+class RotationDegrees:
+    def __init__(self, euler_rot):
+        self.x = round(math.degrees(euler_rot.x))
+        self.y = round(math.degrees(euler_rot.y))
+        self.z = round(math.degrees(euler_rot.z))
+
+
+# This method of stepping through frame by frame and looking at the objects matrix_world
+# was taken from the below export script by @astronotter
+# https://gist.github.com/astronotter/faec735fc5e270df57741705052096ac
+def get_servo_data():
+    frame_range = range(bpy.context.scene.frame_start, bpy.context.scene.frame_end + 1)
+    
+    for obj in get_servo_objects():
+        previous_angle = None
+        for frame in frame_range:
+            bpy.context.scene.frame_set(frame)
+            matrix = obj.matrix_world.copy()
+            # posx, posy, posz = matrix.to_translation()[:]
+            # scalex, scaley, scalez = matrix.to_scale()[:]
+            rot_deg = RotationDegrees(matrix.to_euler())
+            angle = get_moving_angle(obj.name, rot_deg)
+            
+            if previous_angle == angle:
+                continue
+            
+            previous_angle = angle
+            
+            yield (obj.name, [frame2time(frame), angle])
+
+
+def calc_servo_data():
+    servos = {
+            'bottom_rotation': [],
+            'joint_1': [],
+            'joint_2': [],
+            'joint_3': [],
+            'claw_rotation': [],
+            'claw_grip': []
+            }
+
+    for servo_name, servo_data_point in get_servo_data():
+        servos[servo_name].append(servo_data_point)
+
+    return servos
+
+
+class ExportDofbotAnimation(Operator, ExportHelper):
+    """Exports Dofbot animation as json"""
+    bl_idname = "export_dofbot.json_animation"  # important since its how bpy.ops.import_test.some_data is constructed
+    bl_label = "Export Dofbot Json Animation"
+
+    # ExportHelper mixin class uses this
+    filename_ext = ".json"
+
+    filter_glob: StringProperty(
+        default="*.json",
+        options={'HIDDEN'},
+        maxlen=255,  # Max internal buffer length, longer would be clamped.
+    )
+
+    def execute(self, context):
+        servo_data = calc_servo_data()
+        
+        with open(self.filepath, 'w') as f:
+            f.write(json.dumps(servo_data))
+            return {'FINISHED'}
+
+
+# Only needed if you want to add into a dynamic menu
+def menu_func_export(self, context):
+    self.layout.operator(ExportDofbotAnimation.bl_idname, text="Dofbot Animation Export")
+
+
+# Register and add to the "file selector" menu (required to use F3 search "Text Export Operator" for quick access).
+def register():
+    bpy.utils.register_class(ExportDofbotAnimation)
+    bpy.types.TOPBAR_MT_file_export.append(menu_func_export)
+
+
+def unregister():
+    bpy.utils.unregister_class(ExportDofbotAnimation)
+    bpy.types.TOPBAR_MT_file_export.remove(menu_func_export)
+
+
+if __name__ == "__main__":
+    register()
+
+    # test call
+    bpy.ops.export_dofbot.json_animation('INVOKE_DEFAULT')