Wrapped Image Over DEM Appears Blank

I am trying to wrap an image (already read as an array and then converted with the code below) over a digital elevation model with the texture generated from the following piece of code,

def texture_from_np(image):
"""
Creates a tvtk.Texture object from a numpy image array
"""
scalars = tvtk.UnsignedCharArray(name='RGB',
number_of_components=3)
# vtk uses column-major order (Fortan order), whereas
# numpy array is in row-major order (C order) by default
scalars.from_array(image.reshape(-1, 3, order='F'))
tvtk_img = tvtk.ImageData()
tvtk_img.dimensions = [image.shape[0], image.shape[1], 1]
tvtk_img.point_data.scalars = scalars
texture = tvtk.Texture()
texture.set_input_data(tvtk_img)
return texture

However, the DEM appears to be blank. I tried to see if this is a contrast stretching issue by generating a random matrix of zeros and ones and wrap it over the DEM but it appears to be not as the scene is still blank.