Not handling all NERF formats

[mmoyes]

I get the following error

  File "/home/m/work/aos/camorph/m.py", line 4, in <module>
    cams = camorph.read_cameras('nerf',r'/home/m/work/aos/nerfdata/take15_optimized_cams/transforms.json')
  File "/home/m/work/aos/camorph/camorph/camorph.py", line 29, in read_cameras
    cams = src_inst.read_file(*args, **kwargs)
  File "/home/m/work/aos/camorph/camorph/ext/NeRF/NeRF.py", line 144, in read_file
    cam.focal_length_px = [.5 * cam.resolution[0] / np.tan(.5 * camera_angle_x),
TypeError: unsupported operand type(s) for *: 'float' and 'NoneType'

for code

import camorph.camorph as camorph
cams = camorph.read_cameras('nerf',r'/home/m/work/aos/nerfdata/take15_optimized_cams/transforms.json')
camorph.visualize(cams)

It seems camera_angle_x is not being set. Possibly because transforms.json is using a matrix instead;

{
    "camera_model": "OPENCV",
    "frames": [
        {
            "file_path": "images/frame_00001.jpg",
            "w": 3000,
            "h": 4088,
            "fl_x": 10716.10907946319,
            "fl_y": 10716.10907946319,
            "cx": 1381.2775952841873,
            "cy": 2280.181297884072,
            "k1": 0.0971299736922087,
            "k2": -7.007934572579263,
            "k3": 130.90033135432077,
            "k4": 0.0,
            "p1": -0.0024336328994766076,
            "p2": 0.0065866252174946885,
            "transform_matrix": [
                [
                    -0.3353805106176828,
                    0.3177818535863063,
                    -0.8868678631166393,
                    -6.4681681952398336
                ],
                [
                    -0.9415249266924297,
                    -0.08067195141513692,
                    0.3271434680254041,
                    2.4909429428524836
                ],
                [
                    0.032414896492773564,
                    0.944725743158365,
                    0.326255336660165,
                    4.375235441944789
                ],
                [
                    0.0,
                    -0.0,
                    -0.0,
                    1.0
                ]
            ]
        },

...

[bbrand-iis]

Hey mmoyes,

Where did you get this .json file? The problem with this format is that the intrinsics are directly part of the frames array and not global. If you want to handle individual intrinsics, the individual intrinsics need to be under a seperate attribute called "intrinsics" like so:

{
    "camera_model": "OPENCV",
    "frames": [
        {
            "file_path": "images/frame_00001.jpg",
            "intrinsics": {
                "w": 3000,
                "h": 4088,
                "fl_x": 10716.10907946319,
                "fl_y": 10716.10907946319,
                "cx": 1381.2775952841873,
                "cy": 2280.181297884072,
                "k1": 0.0971299736922087,
                "k2": -7.007934572579263,
                "k3": 130.90033135432077,
                "k4": 0.0,
                "p1": -0.0024336328994766076,
                "p2": 0.0065866252174946885
            },
            "transform_matrix": [
                [
                    -0.3353805106176828,
                    0.3177818535863063,
                    -0.8868678631166393,
                    -6.4681681952398336
                ],
                [
                    -0.9415249266924297,
                    -0.08067195141513692,
                    0.3271434680254041,
                    2.4909429428524836
                ],
                [
                    0.032414896492773564,
                    0.944725743158365,
                    0.326255336660165,
                    4.375235441944789
                ],
                [
                    0.0,
                    -0.0,
                    -0.0,
                    1.0
                ]
            ]
        }]
}

Additionally I pushed some changes that should fix the bug you encountered.