def build_volume_bvh(self):
"""
This constructs the mesh that will be ray-traced.
"""
ftype, fname = self.field
mesh_id = int(ftype[-1]) - 1
index = self.data_source.ds.index
offset = index.meshes[mesh_id]._index_offset
field_data = self.data_source[self.field].d # strip units
vertices = index.meshes[mesh_id].connectivity_coords
indices = index.meshes[mesh_id].connectivity_indices - offset
# if this is an element field, promote to 2D here
if len(field_data.shape) == 1:
field_data = np.expand_dims(field_data, 1)
# Here, we decide whether to render based on high-order or
# low-order geometry.
if indices.shape[1] == 27:
# hexahedral
mylog.warning("27-node hexes not yet supported, " +
"dropping to 1st order.")
field_data = field_data[:, 0:8]
indices = indices[:, 0:8]
elif indices.shape[1] == 10:
# tetrahedral
mylog.warning("10-node tetrahedral elements not yet supported, " +
"dropping to 1st order.")
field_data = field_data[:, 0:4]
indices = indices[:, 0:4]
self.volume = BVH(vertices, indices, field_data)
def test_bounding_volume_hierarchy():
ds = yt.load(fn)
vertices = ds.index.meshes[0].connectivity_coords
indices = ds.index.meshes[0].connectivity_indices - 1
ad = ds.all_data()
field_data = ad["connect1", "diffused"]
bvh = BVH(vertices, indices, field_data)
sc = Scene()
cam = Camera(sc)
cam.set_position(np.array([8.0, 8.0, 8.0]))
cam.focus = np.array([0.0, 0.0, 0.0])
origins, direction = get_rays(cam)
image = np.empty(800 * 800, np.float64)
test_ray_trace(image, origins, direction, bvh)
image = image.reshape((800, 800))
return image