Include a test mode rendering function for Instant NGP in the examples

[Linyou]

No description provided.

[liruilong940607]

Thanks Linyou! Do you want to merge this PR in its current state or also adding the usage of this test mode function in the script? I’m happy with both options. Let me know when you done with this PR and want it to be merged.

[Linyou]

Hi, @liruilong940607! Are you suggesting adding an option to the training script that allows switching between train and test modes? If yes, I think the test mode function should be a default option, just like its current state. Since it's closer to the original implementation and faster.

[liruilong940607]

Oh sorry somehow I missed the change you made to the training script.

Changing it to default is reasonable, but in this case we need to carefully verify the metrics do not get affected noticeably comparing to the numbers on the website. -- We don't want future users get inconsistent metrics between the code and the website.

I'm happy to test it out in the weekend. But if you already have those numbers (PSNR & Test Time Diff) would be nice to mark them in this PR for future reference.

[Linyou]

Hi, @liruilong940607. This is what I got using an RTX3090 GPU:

Train Mode Rendering is the original rendering function

NeRF Synthetic

Test Mode Rendering:

Scene	Chair	Drums	Ficus	Hotdog	Lego	Materials	Mic	Ship	Mean
PSNR	35.70	25.09	33.75	37.45	35.73	29.56	36.60	30.39	33.03
Test Time	11.46s	16.51s	14.89s	17.38s	13.42s	18.01s	12.13s	28.91s	16.59s

Train Mode Rendering:

Scene	Chair	Drums	Ficus	Hotdog	Lego	Materials	Mic	Ship	Mean
PSNR	35.69	25.07	33.85	37.47	35.66	29.62	36.86	30.53	33.09
Test Time	31.81s	33.93s	31.68s	45.51s	33.26s	35.89s	30.16s	55.28s	37.19s

NeRF 360:

Test Mode Rendering

Scene	Bicycle	Garden	Bonsai	Counter	Kitchen	Room	Stump	Mean
PSNR	22.38	24.49	30.17	26.86	27.92	30.50	22.31	26.38
Test Time	14.97s	7.12s	6.05s	5.33s	3.90s	5.77s	10.88s	7.72s

Train Mode Rendering

Scene	Bicycle	Garden	Bonsai	Counter	Kitchen	Room	Stump	Mean
PSNR	22.37	24.52	29.94	26.84	27.90	30.50	22.36	26.35
Test Time	22.24s	15.15s	9.85s	8.83s	7.50s	10.19s	14.95s	12.67s

Please note that the Test Time includes the computation of PSNR and is calculated by directly adding the timer to the code at here link

[liruilong940607]

Awesome thanks for providing those numbers!! This looks great!! I'm gonna merge this PR then. Seems like the website do not need to update as the PSNR basically stays the same.

Very cool PR!