统一 2D/3D 深度色条为同一量程。

将 2D 闩锁的深度色彩区间推给 3D 自动着色，固定量程仍跟旋钮。用 test_shared_depth_scale 与深度闩锁冒烟用例验证。

apps/studio/src/orisys_studio/app_window.py

@@ -2331,6 +2331,7 @@ class StudioMainWindow(QMainWindow):
         self._active_calibration_id = ""
         self._depth_range_value = None
         self._last_depth_frame = None
+        self._sync_shared_depth_scale(None)
         # The new session has not established a domain boundary yet; the previous
         # session's island must not survive into it (a different sensor is a different
         # island, and the latch compares against what it holds).
@@ -2652,7 +2653,8 @@ class StudioMainWindow(QMainWindow):
         Re-fitting the range on every frame (the old behaviour) made colours
         drift, so two frames could look identical while holding different
         depths. Latching keeps frames comparable for the whole session; the
-        numeric range is shown in the panel header.
+        numeric range is shown in the panel header. The same span is handed to
+        the 3D pane so both legends name one interval.
         """
         if self._depth_range_value is not None:
             return self._depth_range_value
@@ -2668,8 +2670,15 @@ class StudioMainWindow(QMainWindow):
         if hi <= lo:
             hi = lo + 1.0
         self._depth_range_value = (lo, hi)
+        self._sync_shared_depth_scale(self._depth_range_value)
         return self._depth_range_value
 
+    def _sync_shared_depth_scale(self, span: tuple[float, float] | None) -> None:
+        """Push the latched 2D depth colour span to the 3D surface (or clear it)."""
+        panel = getattr(self, "mesh3d_panel", None)
+        if panel is not None and hasattr(panel, "set_shared_depth_scale"):
+            panel.set_shared_depth_scale(span)
+
     def _depth_scale_text(self, frame: ImageFrame | None = None) -> str:
         """The colour scale, plus — when the frame's depth is exactly zero — why it is flat.
 
@@ -2795,8 +2804,12 @@ class StudioMainWindow(QMainWindow):
         boundary = self._latched_domain_mask(frame)
         self.arrow_panel.set_arrow_scale(arrow_display_scale(draw_style))
         self.arrow_panel.set_valid_area(frame.valid_mask is not None)
-        if mode == DEPTH:
+        # Latch (and sync to 3D) from any depth-carrying frame, not only when the
+        # 2D mode is Depth — the surface may show depth while the canvas shows arrows.
+        if frame.depth is not None:
             self._last_depth_frame = frame.depth
+            self._depth_range()
+        if mode == DEPTH:
             self.arrow_panel.set_depth_scale(self._depth_scale_text(frame))
         else:
             self.arrow_panel.set_depth_scale(None)

apps/studio/src/orisys_studio/scene3d/coordinator.py

@@ -506,6 +506,12 @@ class ThreeDCoordinator:
             # held field frame so the operator sees the change without waiting.
             self._settings_dirty = True
 
+    def set_shared_depth_scale(self, span: tuple[float, float] | None) -> None:
+        """Adopt the 2D canvas's latched depth colour span for automatic colouring."""
+        setter = getattr(self._widget, "set_shared_depth_scale", None)
+        if callable(setter):
+            setter(span)
+
     def set_ramp(self, ramp: str) -> None:
         """Hand the theme's colour ramp to the composer.
 

apps/studio/src/orisys_studio/scene3d/gl_backend.py

@@ -359,6 +359,33 @@ def _scale_bounds(scale, automatic: tuple[float, float] | None) -> tuple[float,
     return lower, upper
 
 
+def _field_scalar_range(
+    field: Any,
+    *,
+    previous: tuple[float, float] | None,
+    shared_depth_scale: tuple[float, float] | None,
+) -> tuple[float, float] | None:
+    """The automatic colour span for the uploaded field.
+
+    Depth shares the 2D canvas's latched ``(lo, hi)`` when the window has one, so the
+    two legends name the same interval. Flow (and depth before that latch exists) keep
+    the measured P5/P95 blend.
+    """
+    descriptor = getattr(field, "descriptor", None)
+    quantity = str(getattr(descriptor, "quantity", "") or "")
+    if quantity == "depth_response" and shared_depth_scale is not None:
+        lo = float(shared_depth_scale[0])
+        hi = float(shared_depth_scale[1])
+        if hi > lo and not (math.isnan(lo) or math.isnan(hi)):
+            return lo, hi
+    measured = _valid_scalar_range(
+        field.scalar,
+        field.valid,
+        signed=bool(getattr(descriptor, "signed", False)),
+    )
+    return _blend_scale_range(previous, measured)
+
+
 def lut_rgba(lut_id: str = "sequential", ramp: str = "") -> np.ndarray:
     """A 256x1 RGBA8 lookup table, built from the **one** ramp both views share.
 
@@ -667,6 +694,9 @@ class GLRenderer:
         #: Range of the valid samples of the field currently uploaded, for the
         #: automatic colour scale. ``None`` until a frame carries valid data.
         self._scalar_range: tuple[float, float] | None = None
+        #: The 2D canvas's latched depth ``(lo, hi)``, when the window has one.
+        #: Depth automatic colouring uses this so both legends name one interval.
+        self._shared_depth_scale: tuple[float, float] | None = None
         #: The colour bounds of the last draw and how they were chosen.
         self._last_scale: tuple[float, float] | None = None
         self._last_scale_mode = ""
@@ -789,10 +819,11 @@ class GLRenderer:
             GL.glBindBuffer(GL.GL_ARRAY_BUFFER, 0)
         self._upload_field_textures(field)
         self._last_upload_ms = (time.perf_counter() - started) * 1000.0
-        measured = _valid_scalar_range(
-            field.scalar, field.valid, signed=bool(field.descriptor.signed)
+        self._scalar_range = _field_scalar_range(
+            field,
+            previous=self._scalar_range,
+            shared_depth_scale=self._shared_depth_scale,
         )
-        self._scalar_range = _blend_scale_range(self._scalar_range, measured)
         self._upload_overlays(frame)
 
     def _upload_field_textures(self, field: Any) -> None:
@@ -987,7 +1018,16 @@ class GLRenderer:
         view = np.asarray(camera.view, dtype=np.float32).reshape(4, 4)
         projection = np.asarray(camera.projection, dtype=np.float32).reshape(4, 4)
         scale = settings.color_scale
-        lower, upper = _scale_bounds(scale, self._scalar_range)
+        # Prefer the 2D latched span at draw time, not only at upload: the latch can
+        # arrive after this field was uploaded, and a repaint must still equalise.
+        automatic = self._scalar_range
+        descriptor = getattr(scale, "descriptor", None) if scale is not None else None
+        if (
+            self._shared_depth_scale is not None
+            and str(getattr(descriptor, "quantity", "") or "") == "depth_response"
+        ):
+            automatic = self._shared_depth_scale
+        lower, upper = _scale_bounds(scale, automatic)
         # What the shader was actually given, for the legend: in automatic mode the
         # operator's spin boxes are disabled and hold values nobody is using, so the
         # panel has to be able to ask what the picture means.
@@ -1061,6 +1101,17 @@ class GLRenderer:
         """The colour bounds the last draw actually used (``None`` before any draw)."""
         return self._last_scale
 
+    def set_shared_depth_scale(self, span: tuple[float, float] | None) -> None:
+        """Adopt the 2D canvas's latched depth colour span, or clear it."""
+        if span is None:
+            self._shared_depth_scale = None
+            return
+        lo, hi = float(span[0]), float(span[1])
+        if hi <= lo or math.isnan(lo) or math.isnan(hi):
+            self._shared_depth_scale = None
+            return
+        self._shared_depth_scale = (lo, hi)
+
     def set_ramp(self, ramp: str) -> None:
         """Adopt the theme's ramp. Rebuilds the LUT at the next draw, once.
 

apps/studio/src/orisys_studio/scene3d/view.py

@@ -107,6 +107,8 @@ class Scene3DView(QWidget):
         #: they cannot drift apart. ``None`` means "no session": the adapter then uses
         #: each frame's own mask, which is what the tests and the PoC want.
         self._domain_latch: Any = None
+        #: The 2D canvas's latched depth colour span, held until the coordinator exists.
+        self._shared_depth_scale: tuple[float, float] | None = None
         self._expected: ExpectedGeometry | None = None
         self._snapshot: Callable[[Any, FrameIdentity], Any] | None = None
         #: The adapter behind ``_snapshot``: it owns the reason a packet was refused,
@@ -148,6 +150,8 @@ class Scene3DView(QWidget):
         self._coordinator = ThreeDCoordinator(
             self._widget, self._composer, self._executor, max_fps=30
         )
+        if self._shared_depth_scale is not None:
+            self._coordinator.set_shared_depth_scale(self._shared_depth_scale)
         self._panel = ThreeDPanel(self._coordinator, self._widget)
         # The picture must not be squeezed out of existence by the controls above it:
         # a GL widget with zero height draws nothing and looks like a broken view.
@@ -313,6 +317,19 @@ class Scene3DView(QWidget):
         if self._adapter is not None and hasattr(self._adapter, "domain_latch"):
             self._adapter.domain_latch = latch
 
+    def set_shared_depth_scale(self, span: tuple[float, float] | None) -> None:
+        """Share the 2D canvas's latched depth colour span with this pane.
+
+        Automatic depth colouring on the surface uses this interval so the 3D legend
+        names the same ``(lo, hi)`` as the 2D depth scale. Fixed mode still follows the
+        operator's spin boxes.
+        """
+        self._shared_depth_scale = None if span is None else (float(span[0]), float(span[1]))
+        if self._coordinator is not None and hasattr(
+            self._coordinator, "set_shared_depth_scale"
+        ):
+            self._coordinator.set_shared_depth_scale(self._shared_depth_scale)
+
     def set_theme(self, theme: str) -> None:
         """Adopt the application theme's colour ramp.
 

apps/studio/src/orisys_studio/scene3d/widget.py

@@ -94,6 +94,13 @@ class Sensor3DWidget(QOpenGLWidget):
         self._rejected_frames = 0
 
     # ------------------------------------------------------------- CPU-side API
+    def set_shared_depth_scale(self, span: tuple[float, float] | None) -> None:
+        """Hand the 2D canvas's latched depth colour span to the GL renderer."""
+        setter = getattr(self._renderer, "set_shared_depth_scale", None)
+        if callable(setter):
+            setter(span)
+        self.update()
+
     def set_scene(self, assets: SceneAssets) -> None:
         """Retain the asset and schedule its upload for the next current context."""
         self._assets = assets

apps/studio/src/orisys_studio/ui/mesh3d_panel.py

@@ -114,6 +114,8 @@ class Mesh3dPanel(QFrame):
         #: The session's island latch, shared with the 2D canvas (see
         #: ``set_domain_latch``). Held until the view exists.
         self._domain_latch = None
+        #: The 2D canvas's latched depth colour span (see ``set_shared_depth_scale``).
+        self._shared_depth_scale: tuple[float, float] | None = None
 
         # Reserve this top-level window's native handle *now*, before the window is
         # shown and while no OpenGL widget exists yet.
@@ -227,6 +229,12 @@ class Mesh3dPanel(QFrame):
         if self._view is not None and hasattr(self._view, "set_theme"):
             self._view.set_theme(self._theme)
 
+    def set_shared_depth_scale(self, span: tuple[float, float] | None) -> None:
+        """Share the 2D depth colour span with the 3D surface (and hold it until built)."""
+        self._shared_depth_scale = None if span is None else (float(span[0]), float(span[1]))
+        if self._view is not None and hasattr(self._view, "set_shared_depth_scale"):
+            self._view.set_shared_depth_scale(self._shared_depth_scale)
+
     def set_domain_latch(self, latch) -> None:
         """Share the 2D canvas's island latch with the 3D pane (see ``Scene3DView``).
 
@@ -321,6 +329,8 @@ class Mesh3dPanel(QFrame):
             view.set_theme(self._theme)
         if self._domain_latch is not None and hasattr(view, "set_domain_latch"):
             view.set_domain_latch(self._domain_latch)
+        if hasattr(view, "set_shared_depth_scale"):
+            view.set_shared_depth_scale(self._shared_depth_scale)
         if self._pending_settings is not None:
             view.restore_settings(self._pending_settings)
         # The kind was decided before the view existed (the window sets it when the