Hands: ft-cutouts, the hand cutouts without pinches and grips

hands/ft-cutouts on|off|status starts ft-camd and ft-hands as transient
user units with ft-hands' new --no-gestures: hands are published for
ft-screens' cutouts, but no pinch or grip is detected, so nothing clicks
or drags and a closing hand doesn't raise the tracking rate. It needs a
build and ft-camd's capabilities, not hands/run.sh install. Its units
conflict with ft-handsctl's, so each stops the other, and they stop with
SteamVR.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

hands/README.md

@@ -14,6 +14,8 @@ Two programs, each a user service that stops when SteamVR does:
 
 They don't start with SteamVR. `hands/run.sh install` builds them, gives ft-camd its capabilities, installs both services disabled, and links `hands/ft-handsctl` into `~/.local/bin`. Then `ft-handsctl on` starts hand tracking and `ft-handsctl off` stops it. `install.sh` doesn't install it.
 
+For the cutouts alone, `hands/ft-cutouts on` starts the same two programs with ft-hands' `--no-gestures`: your hands show through the screens, and no pinch or grip is detected, so nothing clicks or drags. It runs this checkout's build as transient user units, so it needs `hands/build.sh` and ft-camd's capabilities (`hands/run.sh caps`) but not `hands/run.sh install`. It and `ft-handsctl on` stop each other's services, and it stops with SteamVR too.
+
 ```
 ft-handsctl on | off            # on the Frame: start or stop hand tracking (SteamVR must be running)
 ft-handsctl status              # the services, and ft-hands' last status lines
@@ -21,6 +23,8 @@ ft-handsctl log [lines]
 ft-handsctl cutouts on|off|state  # ft-screens' hand cutouts, without stopping tracking
 ft-handsctl gestures            # pinches and grips, live (tools/watch_gestures.py --distance)
 
+hands/ft-cutouts on | off | status   # the cutouts only: no pinches or grips
+
 hands/run.sh install            # build, give ft-camd its capabilities (sudo, once per build), install disabled
 hands/run.sh start|stop         # start or stop the services
 hands/run.sh restart            # after changing a setting
@@ -104,6 +108,7 @@ Options:
 - `--models DIR`: where the models are.
 - `--nice N`: niceness. Default 5, so the VR stack wins contested CPUs.
 - `--no-publish`: don't write the hands and gestures files.
+- `--no-gestures`: hands for the cutouts only. No pinch or grip detection, so nothing reaches the pointer and a closing hand doesn't raise the rate to 30 Hz. The gestures file is removed at start. `ft-cutouts` runs it this way.
 - `--record DIR`, `--record-for S`: save every frame set for S seconds (default 120) to `DIR/sets.bin`. That's about 80 MB/s. Sending the tracker SIGUSR1 (`pkill -USR1 -x ft-hands`) starts a recording in `~/.local/share/frametop/hands/rec-<time>` without a restart. Recordings are images of your hands and room: they stay on the headset unless you move them.
 - `--record-only`: record without tracking or publishing, so it can run beside the live tracker. Give it `--record DIR`, since SIGUSR1 would reach both trackers. With `ft-camd --with-dark`, recordings also hold each camera's newest dark frame as `<name>_dk`, which doubles the rate. With `--with-color`, each colour camera's newest frame is saved with every set, as `color_video<N>`, which adds about 70 MB/s. Run the recorder at normal I/O priority: idle I/O priority stalled a 165 MB/s recording.
 - `--keep-presence P`: the landmark presence a tracked view needs to stay tracked. New views always need 0.5. Default 0.5. Lowering it to 0.2 barely helped in the bright recording, because lost hands drop to near-zero presence.

hands/ft-cutouts

@@ -0,0 +1,56 @@
+#!/usr/bin/env bash
+# ft-cutouts: the hand cutouts without pinches and grips. Your hands show through Frametop's
+# screens, but ft-hands runs with --no-gestures, so nothing clicks or drags. ft-handsctl on is
+# the full version; each stops the other. Like it, this doesn't start with SteamVR, and it
+# stops when SteamVR does. On the Frame.
+#
+#   ft-cutouts on | off | status
+#
+# Runs this checkout's hands/build as transient user units, so it doesn't need hands/run.sh
+# install: only a build (hands/build.sh) and ft-camd's capabilities (hands/run.sh caps).
+set -euo pipefail
+here=$(cd "$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")" && pwd)
+camd=frametop-cutouts-camd.service hands=frametop-cutouts-hands.service
+
+die() { echo "$*" >&2; exit 1; }
+
+run_unit() {  # unit, the ft-handsctl unit it replaces, description, then the command
+  local unit=$1 conflicts=$2 what=$3
+  shift 3
+  systemctl --user -q is-active "$unit" && return
+  systemd-run --user --quiet --collect --unit="$unit" --description="Frametop hand cutouts: $what" \
+    -p PartOf=steamvr.service -p After=steamvr.service -p Conflicts="$conflicts" \
+    -p Restart=always -p RestartSec=5 -p TimeoutStopSec=5 "$@"
+}
+
+case ${1:-status} in
+  on)
+    systemctl --user -q is-active steamvr.service || die "SteamVR isn't running"
+    [ -x "$here/build/ft-camd" ] && [ -x "$here/build/ft-hands" ] || die "not built: hands/build.sh"
+    grep -qa -- --no-gestures "$here/build/ft-hands" || die "ft-hands predates --no-gestures: hands/build.sh"
+    getcap "$here/build/ft-camd" | grep -q cap_sys_ptrace ||
+      die "ft-camd needs its capabilities: hands/run.sh caps (asks for sudo)"
+    if systemctl --user -q is-active frametop-camd.service frametop-hands.service; then
+      echo "stopping ft-handsctl's hand tracking (it has pinches and grips)"
+    fi
+    run_unit $camd frametop-camd.service "the camera broker" "$here/build/ft-camd" --status 60
+    if ! systemctl --user -q is-active $hands; then
+      "$here/../scripts/container-up.sh"  # so stopping the unit can't take the container down
+      pkill -x ft-hands || true
+    fi
+    run_unit $hands frametop-hands.service "hand tracking, no gestures" "$HOME/.local/bin/distrobox" enter dev -- \
+      "$here/build/ft-hands" --status 60 --no-gestures
+    "$here/ft-handsctl" cutouts on >/dev/null || true
+    sleep 4
+    "$0" status ;;
+  off)
+    systemctl --user stop $hands $camd 2>/dev/null || true
+    systemctl --user -q is-active frametop-hands.service || pkill -x ft-hands || true
+    echo "hand cutouts off" ;;
+  status)
+    for u in $camd $hands; do echo "$u: $(systemctl --user is-active $u || true)"; done
+    echo "ft-screens cutouts: $("$here/ft-handsctl" cutouts state 2>&1)"
+    journalctl --user -u $hands --no-pager -o cat -n 40 |
+      grep -E '^ *[0-9.]+s |sets with a hand|cameras:' | tail -2 | cut -c1-160 || true ;;
+  *) sed -n '2,10p' "$0" | sed 's/^# \{0,1\}//'; exit 2 ;;
+esac

hands/track/main.cpp

@@ -3,9 +3,12 @@
 // Python prototype: the same scheduling, with the models on a few threads.
 //
 //   ft-hands [--seconds N] [--threads N] [--int8] [--status S] [--models DIR] [--nice N]
-//            [--no-publish] [--record DIR] [--swap-sides] [--cams auto|mono|color|all] ...
+//            [--no-publish] [--no-gestures] [--record DIR] [--swap-sides] [--cams auto|mono|color|all] ...
 //            (--help lists them all)
 //
+// --no-gestures: hands for the cutouts only. No pinch or grip detection, so nothing reaches
+// the pointer and a closing hand doesn't raise the rate; the gestures file is removed.
+//
 // Which cameras (--cams, HANDS_CAMERAS): the four mono IR cameras light the hands with their
 // own IR and track well in dim rooms, but in bright light (a sunny room, a window behind the
 // hands) they expose for the room and the hands come out dark. The two Arcturus colour
@@ -150,7 +153,7 @@ struct Lighting {
 int main(int argc, char **argv) {
     double seconds = 0, status = 5;
     int threads = 3, niceness = 5;
-    bool int8 = false, publish = true, track = true, swap_sides = false;
+    bool int8 = false, publish = true, track = true, swap_sides = false, gestures_on = true;
     std::string models = std::string(argv[0]).substr(0, std::string(argv[0]).rfind('/') + 1) + "../models/ncnn";
     std::string record, ring_path = "/run/user/" + std::to_string(getuid()) + "/" FH_RING_NAME;
     // SteamOS starts user processes on CPUs 0-4 and keeps 5-7 (two A720s and the X4) for
@@ -189,6 +192,7 @@ int main(int argc, char **argv) {
         else if (a == "--nice" && more) niceness = std::atoi(argv[++i]);
         else if (a == "--int8") int8 = true;
         else if (a == "--no-publish") publish = false;
+        else if (a == "--no-gestures") gestures_on = false;
         else if (a == "--pinch-begin" && more) pinch_params.begin_m = std::atof(argv[++i]);
         else if (a == "--pinch-end" && more) pinch_params.end_m = std::atof(argv[++i]);
         else if (a == "--pinch-triangulated") pinch_params.triangulated = true;
@@ -217,6 +221,7 @@ int main(int argc, char **argv) {
         }
         else {
             std::printf("usage: %s [--seconds N] [--threads N] [--int8] [--status S] [--models DIR] [--nice N] [--no-publish]\n"
+                        "          [--no-gestures] (hands for the cutouts only: no pinches or grips)\n"
                         "          [--record DIR] [--record-for S] [--record-only] [--cpus 5,6,7] [--swap-sides]\n"
                         "          [--keep-presence P] (0.5) [--ring PATH] (ft-camd's, or ft-ringplay's)\n"
                         "          [--cams auto|mono|color|all] (auto) [--bright all|color] (all) [--bright-on L] (40) [--bright-off L] (25)\n"
@@ -265,12 +270,14 @@ int main(int argc, char **argv) {
         return true;
     };
     if (!load_calibration(calib, err) || !ring.open(ring_path.c_str(), err) || !nets.load(models, int8, err) ||
-        (publish && (!pub.open(err) || !gestures.open(pinch, grip, err))) ||
+        (publish && (!pub.open(err) || (gestures_on && !gestures.open(pinch, grip, err)))) ||
         (!record.empty() && !start_recording(record, err))) {
         std::fprintf(stderr, "%s\n", err.c_str());
         return 1;
     }
     if (!ring.alive()) return std::fprintf(stderr, "ft-camd isn't running (no heartbeat)\n"), 1;
+    // so a reader can't take an earlier run's file for this one's
+    if (publish && !gestures_on) unlink((run_dir() + "/gestures").c_str());
 
     std::map<std::string, int> index;   // mono calibration name -> ring camera
     std::map<std::string, int> color;   // colour calibration name (color_video<N>) -> ring camera
@@ -541,9 +548,11 @@ int main(int argc, char **argv) {
         const auto hands = tracker.step(images, int64_t(tmin));
         const uint64_t capture = uint64_t(int64_t(tmin) - raw_off);   // CLOCK_MONOTONIC
         const std::vector<Seen> views = tracker.views_now();
-        grip.update(hands, views, int64_t(capture));
-        pinch.update(hands, views, int64_t(capture), grip.gripping());
-        if (gesture_log && capture - t_glog >= 100'000'000) {
+        if (gestures_on) {
+            grip.update(hands, views, int64_t(capture));
+            pinch.update(hands, views, int64_t(capture), grip.gripping());
+        }
+        if (gestures_on && gesture_log && capture - t_glog >= 100'000'000) {
             t_glog = capture;
             for (int k = 0; k < 2; ++k)
                 if (pinch.world_d[k] >= 0)
@@ -554,7 +563,8 @@ int main(int argc, char **argv) {
         // a gesture down or closing gets the full rate, even while the palm holds still
         next_ns = tmin + uint64_t((std::min(tracker.interval(), pinch.engaged() || grip.engaged() ? 1 / 30.0 : 1.0) -
                                    0.005) * 1e9);
-        if (publish) pub.write(hands, capture), gestures.write(pinch, grip, capture);
+        if (publish) pub.write(hands, capture);
+        if (publish && gestures_on) gestures.write(pinch, grip, capture);
         for (const Pinch::Event &e : grip.events)
             std::printf("grip  %s %-5s curl %.2f at %+.3f %+.3f %+.3f\n", e.side ? "right" : "left ", e.what, e.distance,
                         e.point[0], e.point[1], e.point[2]);
@@ -593,17 +603,19 @@ int main(int argc, char **argv) {
                             s.handoff_miss, s.dups, s.splits, s.created, s.merged, s.forgotten,
                             !rec ? "" : ("  recorded " + std::to_string(rec->written()) + " dropped " +
                                          std::to_string(rec->dropped())).c_str());
-            std::printf("        pinches: left %u right %u (held back, palm down: %d %d)  grips: left %u right %u",
-                        pinch.side(0).begins, pinch.side(1).begins, pinch.held_back[0], pinch.held_back[1],
-                        grip.side(0).begins, grip.side(1).begins);
-            for (int k = 0; k < 2; ++k)
-                if (pinch.side(k).flags & FH_PINCH_TRACKED)
-                    std::printf("  %s %s d %.3f curl %.2f", k ? "right" : "left",
-                                grip.side(k).flags & FH_PINCH_DOWN    ? "GRIP"
-                                : pinch.side(k).flags & FH_PINCH_DOWN ? "PINCH"
-                                                                      : "open",
-                                pinch.side(k).distance, grip.curl[k]);
-            std::printf("\n");
+            if (gestures_on) {
+                std::printf("        pinches: left %u right %u (held back, palm down: %d %d)  grips: left %u right %u",
+                            pinch.side(0).begins, pinch.side(1).begins, pinch.held_back[0], pinch.held_back[1],
+                            grip.side(0).begins, grip.side(1).begins);
+                for (int k = 0; k < 2; ++k)
+                    if (pinch.side(k).flags & FH_PINCH_TRACKED)
+                        std::printf("  %s %s d %.3f curl %.2f", k ? "right" : "left",
+                                    grip.side(k).flags & FH_PINCH_DOWN    ? "GRIP"
+                                    : pinch.side(k).flags & FH_PINCH_DOWN ? "PINCH"
+                                                                          : "open",
+                                    pinch.side(k).distance, grip.curl[k]);
+                std::printf("\n");
+            }
             for (const Hand *h : hands)
                 std::printf("        hand %d %-5s views %d wrist %+.3f %+.3f %+.3f m  scale %.2f  speed %.2f m/s\n", h->id,
                             h->right() ? "right" : "left", h->nviews, h->pts[0][0], h->pts[0][1], h->pts[0][2], h->scale,
@@ -616,8 +628,8 @@ int main(int argc, char **argv) {
         }
     }
     if (!color.empty()) unlink(want_file.c_str());
-    if (publish) {
-        pub.write({}, mono_ns());
+    if (publish) pub.write({}, mono_ns());
+    if (publish && gestures_on) {
         pinch.release(int64_t(mono_ns()));   // a drag in progress ends, as lost
         grip.release(int64_t(mono_ns()));
         gestures.write(pinch, grip, mono_ns());