# Copyright (C) 2020-2025 Motphys Technology Co., Ltd. All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # ============================================================================== """ Geom Size Randomization — Multi-Shape Size Override This example demonstrates per-instance geom size override by randomizing the collision and primitive visual sizes of a sphere, a capsule, a box, a cylinder, and an ellipsoid falling onto a floor. Physical intuition: - Five objects (sphere, capsule, box, cylinder, ellipsoid) fall under gravity. - The objects are spaced apart so the example highlights floor contact rather than object-object contact. - Each of the 16 batch instances has randomly scaled collision sizes. - Larger collision shapes touch the floor sooner and settle higher. - Primitive visual sizes follow the size override, so you can inspect the randomized geometry directly and observe different settling heights across instances. Key concepts: - Per-geom size override using typed subclass APIs: ``GeomSphere.set_size_override``, ``GeomCapsule.set_size_override``, ``GeomCuboid.set_size_override``, ``GeomCylinder.set_size_override``, ``GeomEllipsoid.set_size_override`` - Batch simulation to compare multiple sizes simultaneously Mouse controls: - Press and hold left button then drag to rotate the camera/view - Press and hold right button then drag to pan/translate the view """ import numpy as np from motrixsim import ( GeomCapsule, GeomCuboid, GeomCylinder, GeomEllipsoid, GeomSphere, SceneData, load_mjcf_str, ) from motrixsim.render import RenderApp MJCF = """ """ BATCH = 16 def main(): with RenderApp() as render: model = load_mjcf_str(MJCF) # 4x4 grid layout render_offset = [] for i in range(4): for j in range(4): render_offset.append([-i * 9.0, j * 9.0, 0]) render.launch(model, batch=BATCH, render_offset=render_offset) render.system_camera.set_view(lookat=[-13.5, 13.5, 0.5], distance=40.0, elevation=-35, azimuth=90) data = SceneData(model, batch=(BATCH,)) rng = np.random.default_rng(42) # --- Sphere: randomize radius --- sphere_geom = model.get_geom("sphere") assert isinstance(sphere_geom, GeomSphere) sphere_radii = rng.uniform(0.1, 0.8, size=(BATCH, 1)).astype(np.float32) sphere_geom.set_size_override(data, sphere_radii) # --- Capsule: randomize [radius, half_height] --- capsule_geom = model.get_geom("capsule") assert isinstance(capsule_geom, GeomCapsule) capsule_sizes = np.column_stack( [ rng.uniform(0.1, 0.5, size=BATCH), rng.uniform(0.1, 0.6, size=BATCH), ] ).astype(np.float32) capsule_geom.set_size_override(data, capsule_sizes) # --- Box: randomize half-extents --- box_geom = model.get_geom("box") assert isinstance(box_geom, GeomCuboid) box_sizes = rng.uniform(0.1, 0.6, size=(BATCH, 3)).astype(np.float32) box_geom.set_size_override(data, box_sizes) # --- Cylinder: randomize [radius, half_height] --- cyl_geom = model.get_geom("cyl") assert isinstance(cyl_geom, GeomCylinder) cyl_sizes = np.column_stack( [ rng.uniform(0.1, 0.5, size=BATCH), rng.uniform(0.1, 0.6, size=BATCH), ] ).astype(np.float32) cyl_geom.set_size_override(data, cyl_sizes) # --- Ellipsoid: randomize half-extents --- ellipsoid_geom = model.get_geom("ellipsoid") assert isinstance(ellipsoid_geom, GeomEllipsoid) ellipsoid_sizes = rng.uniform(0.1, 0.6, size=(BATCH, 3)).astype(np.float32) ellipsoid_geom.set_size_override(data, ellipsoid_sizes) # Print summary print("\n" + "=" * 65) print("Geom Size Override — Multi-Shape") print("=" * 65) for i in range(BATCH): r = sphere_radii[i, 0] cap = capsule_sizes[i] b = box_sizes[i] c = cyl_sizes[i] e = ellipsoid_sizes[i] print( f" Instance {i:2d}: sphere r={r:.2f}" f" cap r={cap[0]:.2f} hh={cap[1]:.2f}" f" box=[{b[0]:.2f},{b[1]:.2f},{b[2]:.2f}]" f" cyl r={c[0]:.2f} hh={c[1]:.2f}" f" ell=[{e[0]:.2f},{e[1]:.2f},{e[2]:.2f}]" ) print("=" * 65 + "\n") while True: model.step(data) render.sync(data) if __name__ == "__main__": main()