Reveal the recovered body while the generator loads

The mesh and camera streamed at the motion tail but stayed invisible:
the motion layout has no 3D pane and the diffusion grid replaced it
seconds later, leaving a minutes-long model-loading window staring at
stale detections. The motion tail now switches to a body layout — the
canonical world looping beside the projected source overlay — and the
denoise hook brings in the preview grid when the first step actually
lands.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

fdanyone/rerun_streaming.py

@@ -40,6 +40,7 @@ from fdanyone.viz import (
     DIFFUSION_TIMELINE,
     KEYPOINT_COLOR,
     VIEWS,
+    body_blueprint,
     diffusion_blueprint,
     log_body,
     log_result,
@@ -371,6 +372,8 @@ def _denoise_hook(
         check_stop(session.spec)
         if PREVIEW_DECODER is None:
             return
+        if step_index == 0:
+            recording.send_blueprint(diffusion_blueprint(), make_active=True)
         plan: tuple[tuple[int, int], ...] = preview_slice_plan(x0_hat.shape[2])
         recording.set_time(DIFFUSION_TIMELINE, sequence=step_index)
         with torch.inference_mode():
@@ -510,6 +513,9 @@ def motion_phase(recording: rr.RecordingStream, session: Session) -> Iterator[st
         f"motion: SMPL-X body, parameters, and source camera logged "
         f"(median reprojection error {reprojection_error:.2f} px)",
     )
+    # Reveal the recovered body right away: it loops here through the
+    # generator's model-loading window instead of hiding until the result.
+    recording.send_blueprint(body_blueprint(), make_active=True)
     yield "Generating six views."
 
 
@@ -524,7 +530,8 @@ def generate_phase(recording: rr.RecordingStream, session: Session) -> Iterator[
         raise FourDAnyoneError("The motion phase did not finish.")
     prepared: PreparedRun = session.prepared
     session.source_frames = _decode_source_stills(session.spec)
-    recording.send_blueprint(diffusion_blueprint(), make_active=True)
+    # The body layout from the motion tail stays up while models load; the
+    # denoise hook switches to the preview grid when the first step lands.
     yield "Generating six views."
 
     def work() -> dict:
@@ -577,16 +584,18 @@ def smoke_motion_phase(recording: rr.RecordingStream, session: Session) -> Itera
         log_status(recording, f"[smoke] motion frame {index}")
         time.sleep(SMOKE_DELAY)
         yield f"[smoke] motion frame {index}"
+    recording.send_blueprint(body_blueprint(), make_active=True)
 
 
 def smoke_generate_phase(recording: rr.RecordingStream, session: Session) -> Iterator[str]:
     """Synthetic diffusion phase: gradient frames sharpening per denoising step."""
 
     rng: np.random.Generator = np.random.default_rng(1)
-    recording.send_blueprint(diffusion_blueprint(), make_active=True)
     yield "[smoke] diffusion"
     for step in range(4):
         check_stop(session.spec)
+        if step == 0:
+            recording.send_blueprint(diffusion_blueprint(), make_active=True)
         recording.set_time(DIFFUSION_TIMELINE, sequence=step)
         for view in range(VIEWS):
             noise: UInt8[np.ndarray, "160 88 3"] = rng.integers(

fdanyone/viz.py

@@ -334,6 +334,31 @@ def motion_blueprint() -> rrb.Blueprint:
     )
 
 
+def body_blueprint() -> rrb.Blueprint:
+    """The recovered body looping in 3D while the generator loads its models."""
+
+    import rerun.blueprint as rrb
+
+    return rrb.Blueprint(
+        rrb.Horizontal(
+            rrb.Spatial3DView(origin="world", name="Canonical world"),
+            rrb.Spatial2DView(
+                origin="world/camera",
+                contents=["$origin/**", "/world/body/**"],
+                name="Source",
+            ),
+            rrb.TextLogView(origin="log", name="Progress"),
+            column_shares=[2.0, 1.0, 1.0],
+        ),
+        rrb.TimePanel(
+            timeline=TIME_TIMELINE,
+            play_state="playing",
+            loop_mode="all",
+            state="collapsed",
+        ),
+    )
+
+
 def diffusion_blueprint() -> rrb.Blueprint:
     """A grid of per-view previews that fills in as the denoiser steps."""
 

tests/test_app_helpers.py

@@ -171,6 +171,13 @@ def test_blueprints_build_for_every_phase() -> None:
 
     assert viz.diffusion_blueprint() is not None
 
+    body: rrb.Blueprint = viz.body_blueprint()
+    body_world: rrb.Spatial3DView = body.root_container.contents[0]  # pyrefly: ignore
+    body_source: rrb.Spatial2DView = body.root_container.contents[1]  # pyrefly: ignore
+    assert (body_world.origin, body_world.name) == ("world", "Canonical world")
+    assert body_source.contents == ["$origin/**", "/world/body/**"]
+    assert body.time_panel.play_state == "playing"
+
     result: rrb.Blueprint = viz.result_blueprint(Fraction(25, 1))
     top: rrb.Horizontal = result.root_container.contents[0]  # pyrefly: ignore
     dense: rrb.Horizontal = result.root_container.contents[1]  # pyrefly: ignore