autoware_downsample_filters

Overview

The autoware_downsample_filters is a package that that reduces the number of points of the pointcloud.

Design

The autoware_downsample_filters is implemented for reducing the computational load and improving the performance of the system.

Inner-workings / Algorithms

Random Downsample Filter

pcl::RandomSample is used, which points are sampled with uniform probability.

Voxel Grid Downsample Filter

pcl::VoxelGrid is used, which points in each voxel are approximated with their centroid.

Pickup Based Voxel Grid Downsample Filter

This algorithm samples a single actual point existing within the voxel, not the centroid. The computation cost is low compared to Centroid Based Voxel Grid Filter.

Inputs / Outputs

Input

Output

Parameters

Launch file Parameters

Node Parameters

random_downsample_filter_node

voxel_grid_downsample_filter_node

Usage

1.publish static tf from input pointcloud to target frame that is used for filtering, e.g

ros2 run tf2_ros static_transform_publisher 2.0 3.2 1.3 0 0 0 1  velodyne_top_base_link  base_link

2.launch one of the downsample node

ros2 launch autoware_downsample_filters random_downsample_filter_node.launch.xml

3. launch rviz2 and AWSIM to check the downsample result

Assumptions / Known limits

(Optional) Error detection and handling

(Optional) Performance characterization

(Optional) References/External links

(Optional) Future extensions / Unimplemented parts

Changelog for package autoware_downsample_filters

1.9.0 (2026-06-24)

• Merge remote-tracking branch 'origin/main' into tmp/bot/bump_version_base

• fix([downsample_filters]{.title-ref}): add missing unit tests (#1206)

• refactor([downsample_filters]{.title-ref}): split voxel-grid core logic (#1175)

  • refactor([downsample_filters]{.title-ref}): split voxel-grid core logic
  • extract ROS-independent voxel grid core logic from the node
  • replace callback-based errors in faster voxel filter with ValidationResult
  • propagate validation reasons through core and node logging
  • style(pre-commit): autofix
  • refactor([downsample_filters]{.title-ref}): move field validation into validate_input
  • move x/y/z and intensity field checks from set_field_offsets to validate_input
  • simplify set_field_offsets to a plain void setter
  • remove redundant result check in filter (validation is now upstream)

  * bug: fix the following [cppcheck]{.title-ref} error ` /__w/autoware_core/autoware_core/sensing/autoware_downsample_filters/src/voxel_grid_downsample_filter/voxel_grid_downsample_filter_core.hpp:42:20: performance: inconclusive: Technically the member function 'autoware::downsample_filters::VoxelGridDownsampleFilterCore::validate_input' can be static (but you may consider moving to unnamed namespace). [functionStatic] ValidationResult validate_input(const PointCloud2 & cloud) const; ^ /__w/autoware_core/autoware_core/sensing/autoware_downsample_filters/src/voxel_grid_downsample_filter/voxel_grid_downsample_filter_core.cpp:31:49: note: Technically the member function 'autoware::downsample_filters::VoxelGridDownsampleFilterCore::validate_input' can be static (but you may consider moving to unnamed namespace). ValidationResult VoxelGridDownsampleFilterCore::validate_input(const PointCloud2 & cloud) const ^ /__w/autoware_core/autoware_core/sensing/autoware_downsample_filters/src/voxel_grid_downsample_filter/voxel_grid_downsample_filter_core.hpp:42:20: note: Technically the member function 'autoware::downsample_filters::VoxelGridDownsampleFilterCore::validate_input' can be static (but you may consider moving to unnamed namespace). ValidationResult validate_input(const PointCloud2 & cloud) const; ^[ * bug: fix by `pre-commit]{.title-ref}

  • refactor([downsample_filters]{.title-ref}): align voxel-grid core file naming
  • rename voxel_grid_downsample_filter_core.cpp/hpp to voxel_grid_downsample_filter.cpp/hpp
  • fix: make [set_field_offsets]{.title-ref} private
  • Apply the following review comment:
  • https://github.com/autowarefoundation/autoware_core/pull/1175#discussion_r3433757009
  • refactor([downsample_filters]{.title-ref}): make voxel filter return [tl::expected]{.title-ref}
  • change VoxelGridDownsampleFilterCore::filter to return tl::expected<PointCloud2, std::string>
  • move input validation into filter to avoid accidental validation bypass
  • simplify node call site to early-return on error

  * update unit tests to use the new expected-based interface This fix is proposed by this PR review comment:

  • https://github.com/autowarefoundation/autoware_core/pull/1175#discussion_r3433873891
  • refactor([downsample_filters]{.title-ref}): set output stamp inside core filter
  • Apply the following review comment:
  • https://github.com/autowarefoundation/autoware_core/pull/1175#discussion_r3433884564
  • style(pre-commit): autofix
  • refactor([downsample_filters]{.title-ref}): align core/node naming conventions
  • rename core class to VoxelGridDownsampleFilter in voxel_grid_downsample_filter.cpp/hpp
  • rename ROS2 wrapper class to VoxelGridDownsampleFilterNode in *_node.cpp/hpp
  • refactor([downsample_filters]{.title-ref}): avoid copy when publishing filter output
  • refactor([downsample_filters]{.title-ref}): inline publish of moved filter result
  • bug: fix missing package [tl_expected]{.title-ref}
  • bug: fix build error for test code

  * style(pre-commit): autofix ---------Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

• feat([downsample_filters]{.title-ref}): remove TF operations from voxel grid filter node (#1161)

  • refactor([downsample_filters]{.title-ref}): remove TF operations from voxel grid filter node
  • style(pre-commit): autofix
  • bug: fix wrong conflict resolve in a previous commit
  • style(pre-commit): autofix
  • bug: fix failing tests

  * bug: remove tf-handling code from tests ---------Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

• fix: a bug which causes wrong [frame_id]{.title-ref} propagation in transformation (#1164)

  • bug: fix wrong [frame_id]{.title-ref} propagation in transformation

  * style(pre-commit): autofix ---------Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

File truncated at 100 lines see the full file