leonmkim
commented
1 year ago Firstly, want to say thank you @mikedh for the simply amazing library! Incredibly impressive how much functionality trimesh contains.
Just wanted to suggest, it'd be nice to see some of the functionality, particularly under proximity and collisions, leveraging primitives when possible rather than treating everything as arbitrary meshes. I've been using the primitive generation trimesh provides, but as far as I know, things like signed distance queries and collision queries are not taking advantage of the metadata associated with the primitive geometries. Please correct me if I'm wrong! I've written my own set of SDF queries for the primitives I'm working with right now (boxes, cylinders, spheres) and found the speedup for my use case considerable (just adapted the very comprehensive set of examples from the wonderful Inigo Quilez' site).
def sdf_box(locations, world_tf_box, box_half_dims):
# locations is a Nx3 array
# world_tf_box is a 4x4 transformation matrix
# box_dims is a 3x1 array of [length, width, height]
# returns a Nx1 array of sdf values
# get the inverse transformation matrix
box_tf_world = invert_transform(world_tf_box)
# transform the locations to the box frame
locations_box_frame = tm.transformations.transform_points(locations, box_tf_world)
# get the sdf values (2 norm)
diff = np.abs(locations_box_frame) - box_half_dims #broadcasting to Nx3
# first term handles the case where the point is outside the box
# second term handles the case where the point is inside the box
sdf_values = np.linalg.norm(np.maximum(diff, 0.), axis=1) + np.minimum(np.max(diff, axis=1), 0.)
return sdf_values
def sdf_cylinder(locations, world_tf_cylinder, cylinder_dims):
# locations is a Nx3 array
# world_tf_cylinder is a 4x4 transformation matrix
# cylinder_dims is a 2x1 array of [radius, total_height/2]
# note that height is half the total height
# returns a Nx1 array of sdf values
# get the inverse transformation matrix
cylinder_tf_world = invert_transform(world_tf_cylinder)
# transform the locations to the cylinder frame
locations_cylinder_frame = tm.transformations.transform_points(locations, cylinder_tf_world)
# get the sdf values in euclidean distance
# r,z difference
r_diff = np.linalg.norm(locations_cylinder_frame[:, :2], axis=1) - cylinder_dims[0]
z_diff = np.abs(locations_cylinder_frame[:, 2]) - cylinder_dims[1]
# get the sdf values
# first term handles the case where the point is inside the cylinder
# second term handles the case where the point is outside the cylinder
rz_diff = np.stack([r_diff, z_diff], axis=1)
sdf_values = np.minimum(np.max(rz_diff, axis=1), 0.) + \
np.linalg.norm(np.maximum(rz_diff, 0.), axis=1)
return sdf_values
def sdf_sphere(locations, world_tf_sphere, sphere_radius):
# locations is a Nx3 array
# world_tf_sphere is a 4x4 transformation matrix
# sphere_dims is a scalar of the radius
# returns a Nx1 array of sdf values
# get the inverse transformation matrix
sphere_tf_world = invert_transform(world_tf_sphere)
# transform the locations to the sphere frame
locations_sphere_frame = tm.transformations.transform_points(locations, sphere_tf_world)
# get the sdf values
sdf_values = np.linalg.norm(locations_sphere_frame, axis=1) - sphere_radius
return sdf_valuesI imagine it should also be possible to support leveraging primitives also with collision queries as FCL already does have objects for common primitives...
But perhaps it's simple enough for users like me just to add this functionality on an as-needed basis for themselves rather than offer full support.
villares
RealDanTheMan
mikedh
bguan
Kiord
Kramer84
PR's are always super welcome! This is a relatively small open source project and really benefits from the bugfixes, features, and other stuff the 100+ contributors have PR'd, so thanks!
The previous issue (#199) got pretty out of date and a lot of the stuff on it was done so here's a new thread. Feel free to suggest things!
embree4stuff over the line to be mergedmikedh/embreexfork now has wheels for Mac/Linux/Win Python 3.6-3.11mesh.slice_planehttps://github.com/mikedh/trimesh/issues/1920scene.save_imagealways work. We get a ton of issues about this and the answer is always pretty much "sorry your graphics driver hates you," or "try the docker image." I guess it's just a hard problem that depends a lot on platform and I'm not sure there's any way to solve it from trimeshScene. Maybe now that multi-material single meshes were PR'd in https://github.com/mikedh/trimesh/pull/1246 we could have OBJ always return aTrimesh.trimesh.remesh.subdividesubdivide_to_sizeso that if you specify a subset of faces it splits their neighbors in a way to maintain watertightness.trimesh.path.PathAPI. Specifically:path.polygons_closed->path.linestringspath.polygons_full->path.polygonspath.pathandpath.discrete.pyright trimeshpasspyright trimesh/graph.py.