astrokit ephemeris

readme.md

@@ -8,10 +8,11 @@ optics and detector, so an image should match what a real camera with the same
 parameters records.
 
 It is built for closed-loop simulation, where each step renders one frame and
-latency is the number that matters. The target is 1–2 MP RGB in under 100 ms
-end to end on a mid-range GPU (the reference is an RTX 3060). Lighting fidelity
-and camera fidelity are selected separately, and each tier is benchmarked, so
-a run can trade fidelity for speed knowing what each step costs.
+latency is the number that matters. The goal is high-fidelity 1–2 MP RGB in
+about 10 ms end to end on a mid-range GPU (the reference is an RTX 3060);
+100 ms is the ceiling, not the aim. Lighting fidelity and camera fidelity are
+selected separately, and each tier is benchmarked, so a run can trade
+fidelity for speed knowing what each step costs.
 
 Rendering goes through wgpu. On a machine without a GPU, the same shaders run
 on the CPU through Mesa's lavapipe (`vulkan-swrast` on Arch,
@@ -60,6 +61,15 @@ assert!(frame.dn_at(960, 540, 1) > 1000);
 # }
 ```
 
+## Features
+
+- `astrokit`: build a `Scene` from an epoch with
+  [astrokit](https://git.rcjohnstone.com/connor/astrokit)'s ephemerides (JPL
+  DE440s for the Sun and Moon, ITRF93 for Earth's orientation), through
+  `ephemeris::Ephemeris`. astrokit is not on crates.io, so this expects a
+  checkout at `../astrokit` next to this repository, and its kernels from its
+  `scripts/fetch-kernels.sh` (or `ASTROKIT_KERNELS` pointing at them).
+
 ## Status
 
 M1 in progress: the library renders Earth, Moon, Sun and targets to DN