How to render an image with the correct camera position ?

[MatteoMarengo]

Hello,

I would need help on a specific task.

I am working on the nuScenes dataset and I want to render a mesh with the right camera viewpoint.

I have a texture map (a .png file) and I define my 2D mesh as a rectangle consisting of two triangles.

Here is my .obj file :

mtllib simple_mesh.mtl

v 33.11250686645508 -50.19285202026367 0.0
v 133.11233520507812 -50.19285202026367 0.0
v 133.11233520507812 49.67078399658203 0.0
v 33.11250686645508 49.67078399658203 0.0
vt 0.0 0.0
vt 1.0 0.0
vt 1.0 1.0
vt 0.0 1.0
f 1/1 2/2 3/3
f 1/1 3/3 4/4

I also have the camera parameters:

camera_params = {
"frames": [
{
"file_path": "samples/CAM_FRONT/n008-2018-08-27-11-48-51-0400__CAM_FRONT__1535385092112404.jpg",
"time": 1535385092112404,
"transform_matrix": [
[0.009996810324503643, -0.9998783580101878, -0.01197217466409921, 0.00912502329035999],
[0.008842632746802154, 0.012060700994871545, -0.9998881674155458, 1.4819740829478583],
[0.9999109318481532, 0.00988982681163363, 0.008962125651585906, -1.4544289915843547],
[0.0, 0.0, 0.0, 1.0]
],
"intrinsics": [
[1252.8131021185304, 0.0, 826.588114781398],
[0.0, 1252.8131021185304, 469.9846626224581],
[0.0, 0.0, 1.0]
],
"is_key_frame": True
}
]
}

Therefore I can have my R and my T, but when I am doing the rendering using the MeshRenderer (I have defined cameras with the correct R and T), I only observe a white background.

Thank you so much !