Add parent_node and transform to add_geometry

[wkentaro]

This and #256 helps to build scene more easily.

Scene

Before (without this and #256)

#!/usr/bin/env python

import numpy as np
import trimesh
import trimesh.transformations as tf


scene = trimesh.Scene()

# plane
plane = trimesh.creation.box(extents=[1, 1, 0.01])
plane.visual.face_colors = [0.5, 0.5, 0.5, 0.5]
scene.add_geometry(plane)
scene.add_geometry(trimesh.creation.axis())

# object-1 (box)
box = trimesh.creation.box(extents=[0.3, 0.3, 0.3])
box.visual.face_colors = [0, 1., 0, 0.5]
axis = trimesh.creation.axis(origin_color=[1., 0, 0])
translation = [-0.2, 0, 0.15 + 0.01]  # box offset + plane offset
box.apply_translation(translation)
axis.apply_translation(translation)
rotation = tf.rotation_matrix(np.deg2rad(30), [0, 0, 1], point=box.centroid)
box.apply_transform(rotation)
axis.apply_transform(rotation)
scene.add_geometry(box)
scene.add_geometry(axis)

# object-2 (cylinder)
cylinder = trimesh.creation.cylinder(radius=0.1, height=0.3)
cylinder.visual.face_colors = [0, 0, 1., 0.5]
axis = trimesh.creation.axis(origin_color=[1., 0, 0])
translation = [0.1, -0.2, 0.15 + 0.01]  # cylinder offset + plane offset
cylinder.apply_translation(translation)
axis.apply_translation(translation)
scene.add_geometry(cylinder)
scene.add_geometry(axis)

scene.show()

After

#!/usr/bin/env python

import numpy as np
import trimesh
import trimesh.transformations as tf


scene = trimesh.Scene()

# plane
plane = trimesh.creation.box(
    extents=[1, 1, 0.01], face_colors=[0.5, 0.5, 0.5, 0.5]
)
node_name = scene.add_geometry(plane)
scene.add_geometry(trimesh.creation.axis(), parent_node_name=node_name)

# object-1 (box)
box = trimesh.creation.box(extents=[0.3, 0.3, 0.3], face_colors=[0, 1, 0, 0.5])
translation = tf.translation_matrix([-0.2, 0, 0.15 + 0.01])
rotation = tf.rotation_matrix(np.deg2rad(30), [0, 0, 1], point=box.centroid)
transform = rotation @ translation
node_name = scene.add_geometry(box, transform=transform)
axis = trimesh.creation.axis(origin_color=[1., 0, 0])
scene.add_geometry(axis, parent_node_name=node_name)

# object-2 (cylinder)
cylinder = trimesh.creation.cylinder(
    radius=0.1, height=0.3, face_colors=[0, 0, 1., 0.5]
)
axis = trimesh.creation.axis(origin_color=[1., 0, 0])
translation = tf.translation_matrix([0.1, -0.2, 0.15 + 0.01])
node_name = scene.add_geometry(cylinder, transform=translation)
scene.add_geometry(axis, parent_node_name=node_name)

scene.show()

[coveralls]

Coverage decreased (-0.04%) to 84.336% when pulling 3d08af2 on wkentaro:parent_node_transform into 6665426 on mikedh:master.

[wkentaro]

Will be merged with https://github.com/mikedh/trimesh/tree/camera_merge