我目前正在python中进行体积渲染项目，在此情况下，给定由体素组成的3D体积，我使用合成射线投射功能来生成图像。该函数（我在下面显示）可以正常运行，但是运行时间很长。你们有如何使此功能更快的提示吗？代码是Python 3.6.8，并使用各种numpy数组。
def render_compositing(self, view_matrix: np.ndarray, volume: Volume, image_size: int, image: np.ndarray):
# Clear the image
self.clear_image()
# U, V, View vectors. See documentation in parent's class
u_vector = view_matrix[0:3]
v_vector = view_matrix[4:7]
view_vector = view_matrix[8:11]
# Center of the image. Image is squared
image_center = image_size / 2
# Center of the volume (3-dimensional)
volume_center = [volume.dim_x / 2, volume.dim_y / 2, volume.dim_z / 2]
# Define a step size to make the loop faster
step = 2 if self.interactive_mode else 1
for i in range(0, image_size, step):
for j in range(0, image_size, step):
sum_color = TFColor(0, 0, 0, 0)
for k in range(0, image_size, step):
# Get the voxel coordinate X
voxel_coordinate_x = u_vector[0] * (i - image_center) + v_vector[0] * (j - image_center) + \
view_vector[0] * (k - image_center) + volume_center[0]
# Get the voxel coordinate Y
voxel_coordinate_y = u_vector[1] * (i - image_center) + v_vector[1] * (j - image_center) + \
view_vector[1] * (k - image_center) + volume_center[1]
# Get the voxel coordinate Y
voxel_coordinate_z = u_vector[2] * (i - image_center) + v_vector[2] * (j - image_center) + \
view_vector[2] * (k - image_center) + volume_center[2]
color = self.tfunc.get_color(
get_voxel(volume, voxel_coordinate_x, voxel_coordinate_y, voxel_coordinate_z))
sum_color.r = color.a * color.r + (1 - color.a) * sum_color.r
sum_color.g = color.a * color.g + (1 - color.a) * sum_color.g
sum_color.b = color.a * color.b + (1 - color.a) * sum_color.b
sum_color.a = color.a + (1 - color.a) * sum_color.a
red = sum_color.r
green = sum_color.g
blue = sum_color.b
alpha = sum_color.a
# Compute the color value (0...255)
red = math.floor(red * 255) if red < 255 else 255
green = math.floor(green * 255) if green < 255 else 255
blue = math.floor(blue * 255) if blue < 255 else 255
alpha = math.floor(alpha * 255) if alpha < 255 else 255
# Assign color to the pixel i, j
image[(j * image_size + i) * 4] = red
image[(j * image_size + i) * 4 + 1] = green
image[(j * image_size + i) * 4 + 2] = blue
image[(j * image_size + i) * 4 + 3] = alpha
我不明白为什么要为此代码使用python。如果您担心速度，使用着色器不是更好的方法吗？
无论如何，在当前代码中，这里有几件事可以完成。