From 1d4b7059aa969875dbd4904c8a6980afdb39f647 Mon Sep 17 00:00:00 2001
From: Adrian Kummerlaender
Date: Fri, 10 Jan 2020 18:10:35 +0100
Subject: Implement model for local sun direction

`local_sunrise.py` renders the sky for a given time and place on earth.
---
 local_sunrise.py | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 local_sunrise.py

(limited to 'local_sunrise.py')

diff --git a/local_sunrise.py b/local_sunrise.py
new file mode 100644
index 0000000..58ec73d
--- /dev/null
+++ b/local_sunrise.py
@@ -0,0 +1,67 @@
+import numpy as np
+import matplotlib.pyplot as plt
+from string import Template
+
+import pyopencl as cl
+from pyopencl.cltypes import make_double3
+
+mf = cl.mem_flags
+
+from planets import earth
+
+from sun import sun_direction
+from datetime import datetime
+
+config = {
+    'size_x': 1920//4,
+    'size_y': 1080//4,
+
+    'ray_samples'  : 16,
+    'light_samples': 8,
+
+    'exposure': 2.0,
+    'zoom':     1.0,
+
+    'eye_pos': np.array([0, 0, 1.0001]),
+    'eye_dir': np.array([0, 1, 0]),
+
+    'date': (2020, 1, 10),
+    'latitude': 49.01,
+    'longitude': 8.4
+}
+
+time_range = (5, 20, 1)
+
+cl_platform = cl.get_platforms()[0]
+cl_context = cl.Context(properties=[(cl.context_properties.PLATFORM, cl_platform)])
+cl_queue   = cl.CommandQueue(cl_context)
+
+cl_picture = cl.Buffer(cl_context, mf.WRITE_ONLY, size=config['size_x']*config['size_y']*3*np.float64(0).nbytes)
+program = None
+
+with open('raymarch.cl') as f:
+    program = cl.Program(cl_context, Template(f.read()).substitute(
+        {**config, **earth}
+    )).build()
+
+for time in np.arange(*time_range):
+    pit = datetime(*config['date'], int(np.floor(time)), int((time-np.floor(time))*60), 0)
+    sun_dir = sun_direction(config['latitude'], config['longitude'], pit, 1.0)
+
+    sun = make_double3(
+        np.sin(sun_dir[1])*np.cos(sun_dir[0]),
+        np.cos(sun_dir[1])*np.cos(sun_dir[0]),
+        np.sin(sun_dir[0])
+    )
+    print(sun_dir)
+
+    program.render(
+        cl_queue, (config['size_x'], config['size_y']), None, cl_picture,
+        make_double3(*(config['eye_pos'] * earth['earth_radius'])),
+        make_double3(*(config['eye_dir'] * earth['earth_radius'])),
+        sun)
+
+    np_picture = np.ndarray(shape=(config['size_y'], config['size_x'], 3), dtype=np.float64)
+    cl.enqueue_copy(cl_queue, np_picture, cl_picture).wait();
+
+    plt.imsave("sky_%05.1f.png" % time, np_picture, origin='lower')
-- 
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