[TomCC7]

DimSim's browser and Deno physics/lidar producers now publish canonical CDR Image, PoseStamped and PointCloud2 values and consume canonical Twist commands. Raw LCM/LC02 WebSocket framing, relay fragmentation, coordinate transforms, physics integration and command deadman remain. The Python connection uses matching generated odom/TF transports and closes its owned TF endpoint on shutdown.

The browser publishes original RGBA canvas pixels in an rgba8 Image; the existing eval/sidebar JPEG stays separate. Depth keeps the existing uint16 millimeter/clamping behavior. The CLI invalidates a cached frontend when CDR sources, schemas or manifests change, so a previously-built legacy browser cannot silently remain paired with a new server.

Project: https://linear.app/dimensional/project/message-encoding-refactor-05a3ddb4af3e/overview

Parent: #4719 (91847472a2bfb0641a01d487436986906c39e693). This proposal's remaining platform graphs, historical fixtures, final cleanup and logical PR organization are still open.

flowchart LR
  PythonTwist[Python generated Twist] --> RawLCM[Raw LCM / CDR payload]
  RawLCM --> Physics[Deno / Rapier physics]
  Physics --> Pose[CDR PoseStamped]
  Pose --> TF[Python canonical TF]
  Canvas[Browser canvas RGBA / depth] --> WS[CDR Image in LC02 WebSocket frame]
  WS --> Relay[Existing raw LCM relay]
  Lidar[Rapier lidar] --> Cloud[CDR PointCloud2]
  Cloud --> Relay
  Relay --> PythonSensors[Python generated sensor values]

Loading

File change summary

Category	Files	Added	Deleted	Review focus
Runtime/producer/cache adapters	8	182	130	Matching CDR channels; raw pixel rows; same physics/lidar math; odom-to-TF ownership; old-dist invalidation
Behavior tests	2	403	0	Independent Python/Deno codecs; actual browser methods; actual bounded CPU Rapier/deadman/lidar; real memq TF and cleanup
Generated schema artifact	1	6	0	Four complete schemas exported from canonical installed messages; exact registry-equality test; no independent .msg source definitions
Existing docs / CI	2	44	0	Embedded offline command and installed-package acceptance
Package manifests	2	5	2	Fixed Foxglove rosmsg5.0.5 / rosmsg2-serialization3.1.2; old message-codec import removed
Dependency locks	2	binary	binary	Existing LFS-tracked Deno/NPM locks updated

Verification

• 27 source tests and the same 27 against an independently installed main wheel, using isolated Python and site-packages assertions. These include three real Deno test cases run with cached dependencies and no network permission.
• Python big/little-endian generated payloads round-trip through Foxglove with exact canonical bytes. Invalid encapsulation/trailing bytes fail without a legacy fallback.
• Actual browser publishing methods preserve RGBA pixels, shared clock, depth units/clamping and WS frames larger than UDP's limit.
• Actual CPU Rapier runs two bounded physics frames and one lidar scan: positive command movement, deadman-to-zero, ROS coordinates, real floor intersections and cloud layout are independently decoded/asserted in Python. The external UDP boundary is fake; no benchmark/throughput measurement ran.
• Actual memq generated odom -> connection -> TF, exact source nanoseconds, mount values, independent headers and endpoint cleanup. Existing Go2/DimSim process regressions pass.
• Scoped Python strict typing and five Deno files pass. Both NPM Vite and the actual Deno CLI build path pass; an old cached dist rebuilds, then the matching artifact is reused. Configured scoped hooks pass except unavailable Nix lint.
• Wheel SHA-256: dc5657681dd2dbfb6f94e36452bea42ee7d220d3eaebb6c44bae00f5b7a9b91f.

Manual offline test

With development dependencies and Deno available:

cd misc/DimSim
deno install --no-lock
deno run --allow-all --unstable-net cli/cli.ts build
cd ../..
DIMOS_DIMSIM_DENO="$(command -v deno)" DIMOS_TRANSPORT=lcm LCM_DEFAULT_URL=memq:// \
  uv run pytest -o addopts='' --import-mode=importlib -q \
  dimos/robot/unitree/test_dimsim_connection.py \
  dimos/simulation/dimsim/test_dimsim_process.py \
  dimos/robot/unitree/go2/test_connection.py

The first preparation may download declared dependencies; no checkpoint, hardware, rendered scene, host-network change, real multicast acceptance or human visual acceptance is claimed. DimSim continues to require its source/assets checkout; this does not claim the full simulator is bundled in a main wheel. No CI result is claimed or polled. Rich numerical driver helper types remain behind boundaries; legacy dependency retirement is separate.