Can not render only the outputs of the static background node

[letian-zhang]

Hi,

I run the example in the Rendering a Sequence with 'bckg_only=True'.
Also, I test the code for all dynamic parts with 'obj_only=True' & 'white_bkgd=True'.
However, both two cases have a error.
ValueError: all the input array dimensions for the concatenation axis must match exactly, but along dimension 0, the array at index 0 has size 112 and the array at index 1 has size [98.]

This is because in the main.py line 1518.
rays_rgb = np.concatenate([rays, images[:, None, ...]], 1)
The size of rays is (112, 2, 375, 1242, 3) and the size of images is (98, 1, 375, 1242, 3). They can not concatenate together.
How to solve this problem?

Thank you for any suggestion.
Letian