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docs/examples/.gitignore

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+01_render_scene/*.jpg
+01_render_scene/*.exr
+02_depth_integrator/*.jpg
+02_depth_integrator/*.exr

docs/examples/01_render_scene/render_scene.py

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+import os
+
+from mitsuba.core import Bitmap, Struct, Thread
+from mitsuba.core.xml import load_file
+
+
+SCENE_DIR = '../../../resources/data/scenes/'
+filename = os.path.join(SCENE_DIR, 'cbox/cbox.xml')
+
+# Append the directory containing the scene to the "file resolver".
+# This is needed since the scene specifies meshes and textures
+# using relative paths.
+directory_name = os.path.dirname(filename)
+Thread.thread().file_resolver().append(directory_name)
+
+# Load the actual scene
+scene = load_file(filename)
+
+# Call the scene's integrator to render the loaded scene
+scene.integrator().render(scene)
+
+# After rendering, the rendered data is stored in the film
+film = scene.sensor().film()
+
+# Write out rendering as high dynamic range OpenEXR file
+film.bitmap().convert(Bitmap.ERGB, Struct.EFloat32, srgb_gamma=False).write('cbox.exr')
+
+# Write out a tonemapped JPG of the same rendering
+film.bitmap().convert(Bitmap.ERGB, Struct.EUInt8, srgb_gamma=True).write('cbox.jpg')

docs/examples/02_depth_integrator/depth_integrator.py

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+import os
+import numpy as np
+
+from mitsuba.core import Bitmap, Struct, Thread
+from mitsuba.core.xml import load_file
+
+from mitsuba.core import Bitmap, EDebug, Log
+from mitsuba.render import RadianceSample3fX, ImageBlock
+
+SCENE_DIR = '../../../resources/data/scenes/'
+filename = os.path.join(SCENE_DIR, 'cbox/cbox.xml')
+
+# Append the directory containing the scene to the "file resolver".
+# This is needed since the scene specifies meshes and textures
+# using relative paths.
+directory_name = os.path.dirname(filename)
+Thread.thread().file_resolver().append(directory_name)
+
+# Load the actual scene
+scene = load_file(filename)
+
+# Instead of calling the scene's integrator, we build our own small integrator
+# This integrator simply computes the depth values per pixel
+sensor = scene.sensor()
+film = sensor.film()
+film_size = film.crop_size()
+spp = 32
+
+# Sample pixel positions in the image plane
+# Inside of each pixels, we randomly choose starting locations for our rays
+n_rays = film_size[0] * film_size[1] * spp
+pos = np.arange(n_rays) / spp
+scale = np.array([1.0 / film_size[0], 1.0 / film_size[1]])
+pos = np.stack([pos % int(film_size[0]), pos / int(film_size[0])], axis=1)
+position_sample = pos + np.random.rand(n_rays, 2).astype(np.float32)
+
+active = np.ones(n_rays).astype(np.bool)
+
+# Sample rays starting from the camera sensor
+rays, weights = sensor.sample_ray_differential(
+    time=0,
+    sample1=np.random.rand(n_rays).astype(np.float32),
+    sample2=position_sample * scale,
+    sample3=np.random.rand(n_rays, 2).astype(np.float32),
+    active=active)
+
+# Intersect rays with the scene geometry
+surface_interaction = scene.ray_intersect(rays)
+
+# Given intersection, compute the final pixel values as the depth t
+# of the sampled surface interaction
+result = surface_interaction.t
+result[~surface_interaction.is_valid()] = 0 # set values to zero if no intersection occured
+
+
+# Accumulate values into an image block
+rfilter = film.reconstruction_filter()
+block = ImageBlock(Bitmap.EXYZAW, film.crop_size(), warn=False, filter=rfilter, border=False)
+result = np.stack([result, result, result, result], axis=1) # Workaround since ImageBlock assumes 4 values
+block.put(position_sample, rays.wavelengths, result, 1)
+
+# Write out the result from the ImageBlock
+block.bitmap().convert(Bitmap.EY, Struct.EFloat32, srgb_gamma=False).write('depth.exr')
+