[feat]: wire in scene into the simulation engine

1 files changed, 6 insertions, 0 deletions

diff --git a/src/scene/scene_types.h b/src/scene/scene_types.h
index d34983f..61bea35 100644
--- a/src/scene/scene_types.h
+++ b/src/scene/scene_types.h
@@ -8,6 +8,12 @@ namespace Donut
     // portable renderers (SceneRenderer, BlackHoleRenderer). The rendering itself
     // is written once on the RHI (rendering/rhi.h); these are just the inputs.
 
+    // The scene editor and the simulation share ONE world at this scale: this many
+    // grid units == one Schwarzschild radius. The SceneRenderer draws the hole's
+    // horizon at this radius; the BlackHoleRenderer maps scene positions into
+    // physical units (x SagA_rs / SCENE_UNITS_PER_RS) so placed objects line up.
+    constexpr float SCENE_UNITS_PER_RS = 3.0f;
+
     // A placeable/editable sphere in the world-builder scene view. The app owns
     // the list; SceneRenderer draws it the same way on every backend.
     struct SceneObject