GGUI depth information and color information or imwrite broken

[sarahhaha]

Describe the bug
The GGUI depth information and color information give inaccurate information to the actual scene rendering

To Reproduce

if mode == 'rgbd':
            frame = 'first_last' #'all' #'first_last'
            foodname = 'spaghetti1'
            filename = f'frame_{self.i:05d}.png'
            start_frame = 100
            last_frame = 270

            if frame == 'all' or (frame == 'first_last' and (self.i == start_frame or self.i == last_frame)):
                depth = self.window.get_depth_buffer_as_numpy()
                depth = depth * depth * depth * 100 * 100
                # Save the depth image
                ti.tools.imwrite(depth, f'/home/empriselab/FluidLab/fluidlab/data/depth/{foodname}_{filename}')
                
                img = (self.window.get_image_buffer_as_numpy())[:, :, :3]
                img = (img * 255).astype(np.uint8)
                # Save the rgb image
                ti.tools.imwrite(img, f'/home/empriselab/FluidLab/fluidlab/data/rgb/{foodname}_{filename}')
                
                #sleep(0.1)
                self.window.destroy()
                self.init_window(mode)
                self.window.show()

            return None

Log/Screenshots
These are images produced by get_depth_buffer_as_numpy(), get_image_buffer_as_numpy() and ti.tools.imwrite()

Meanwhile, this is the actual GGUI scene video.

fast6-2023-12-22_00.37.38-2024-01-23_22.30.04.mp4

The ply export from GGUI works well. This is the ply exported from this scene and imported into blender.

fast6-2023-12-22_00.37.38-2024-01-23_22.32.06.mp4

Full log

$python fluidlab/run.py --cfg_file configs/exp_spaghetti.yaml --record
[Taichi] version 1.5.0, llvm 15.0.4, commit 7b885c28, linux, python 3.7.13
[Taichi] Starting on arch=cuda
===>  TaichiEnv created.
===>      501 particles of spaghetti     mesh added.
===>      501 particles of spaghetti     mesh added.
===>      501 particles of spaghetti     mesh added.
===>      501 particles of spaghetti     mesh added.
===>      501 particles of spaghetti     mesh added.
===>      501 particles of spaghetti     mesh added.
===>      501 particles of spaghetti     mesh added.
===>      501 particles of spaghetti     mesh added.
===>      501 particles of spaghetti     mesh added.
===>  SpaghettiEnv built successfully.
/home/empriselab/miniconda3/envs/fluidlab/lib/python3.7/site-packages/taichi/lang/struct.py:247: DeprecationWarning: fill() on ti.Struct is deprecated, and it will be removed in Taichi v1.6.0.
  DeprecationWarning)
/home/empriselab/FluidLab/fluidlab/fluidengine/simulators/mpm_simulator.py:371: DeprecationWarning: Calling builtin function "max" in Taichi scope is deprecated, and it will be removed in Taichi v1.6.0.Please use "ti.max" instead.
  S_new[d, d] = min(max(self.particles[f, p].S[d, d], 1 - 2e-3), 1 + 3e-3)
/home/empriselab/FluidLab/fluidlab/fluidengine/simulators/mpm_simulator.py:371: DeprecationWarning: Calling builtin function "min" in Taichi scope is deprecated, and it will be removed in Taichi v1.6.0.Please use "ti.min" instead.
  S_new[d, d] = min(max(self.particles[f, p].S[d, d], 1 - 2e-3), 1 + 3e-3)
/home/empriselab/FluidLab/fluidlab/fluidengine/simulators/mpm_simulator.py:394: DeprecationWarning: Operator "is not" in Taichi scope is deprecated, and it will be removed in Taichi v1.6.0. Please avoid using it.
  if ti.static(self.agent is not None):
===> New target generated and dumped to /home/empriselab/FluidLab/fluidlab/assets/targets/Spaghetti-v0.pkl.

Additional comments
ti diagnose
[Taichi] version 1.5.0, llvm 15.0.4, commit 7b885c2, linux, python 3.7.13

---

** Taichi Programming Language **

---

Docs: https://docs.taichi-lang.org/
GitHub: https://github.com/taichi-dev/taichi/
Forum: https://forum.taichi.graphics/

Taichi system diagnose:

python: 3.7.13 (default, Mar 29 2022, 02:18:16)
[GCC 7.5.0]
system: linux
executable: /home/empriselab/miniconda3/envs/fluidlab/bin/python
platform: Linux-5.15.0-91-generic-x86_64-with-debian-bullseye-sid
architecture: 64bit
uname: uname_result(system='Linux', node='Taughannock', release='5.15.0-91-generic', version='#101~20.04.1-Ubuntu SMP Thu Nov 16 14:22:28 UTC 2023', machine='x86_64', processor='x86_64')
locale: en_US.UTF-8
PATH: /home/empriselab/miniconda3/envs/fluidlab/bin:/opt/ros/noetic/bin:/home/empriselab/miniconda3/condabin:/home/empriselab/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/home/empriselab/bin
PYTHONPATH: ['/home/empriselab/miniconda3/envs/fluidlab/bin', '/home/empriselab/Workspace/premanip_robot/premanip_ws/devel/lib/python3/dist-packages', '/opt/ros/noetic/lib/python3/dist-packages', '/home/empriselab/miniconda3/envs/fluidlab/lib/python37.zip', '/home/empriselab/miniconda3/envs/fluidlab/lib/python3.7', '/home/empriselab/miniconda3/envs/fluidlab/lib/python3.7/lib-dynload', '/home/empriselab/miniconda3/envs/fluidlab/lib/python3.7/site-packages', '/home/empriselab/FluidLab', '/home/empriselab/premanip_ws/src/deoxys_control/deoxys']

No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 20.04.6 LTS
Release: 20.04
Codename: focal

import: <module 'taichi' from '/home/empriselab/miniconda3/envs/fluidlab/lib/python3.7/site-packages/taichi/init.py'>

cc: False
cpu: True
metal: False
opengl: True
cuda: True
vulkan: True

glewinfo not available: [Errno 2] No such file or directory: 'glewinfo': 'glewinfo'

Tue Jan 23 22:38:50 2024
+---------------------------------------------------------------------------------------+
| NVIDIA-SMI 545.23.08 Driver Version: 545.23.08 CUDA Version: 12.3 |
|-----------------------------------------+----------------------+----------------------+
| GPU Name Persistence-M | Bus-Id Disp.A | Volatile Uncorr. ECC |
| Fan Temp Perf Pwr:Usage/Cap | Memory-Usage | GPU-Util Compute M. |
| | | MIG M. |
|=========================================+======================+======================|
| 0 NVIDIA GeForce RTX 3060 On | 00000000:01:00.0 On | N/A |
| 0% 50C P8 15W / 170W | 1435MiB / 12288MiB | 5% Default |
| | | N/A |
+-----------------------------------------+----------------------+----------------------+

+---------------------------------------------------------------------------------------+
| Processes: |
| GPU GI CI PID Type Process name GPU Memory |
| ID ID Usage |
|=======================================================================================|
| 0 N/A N/A 1269 G /usr/lib/xorg/Xorg 53MiB |
| 0 N/A N/A 2667 G /usr/lib/xorg/Xorg 518MiB |
| 0 N/A N/A 451715 G /usr/bin/gnome-shell 64MiB |
| 0 N/A N/A 487169 G /usr/lib/xorg/Xorg 85MiB |
| 0 N/A N/A 796283 G ...seed-version=20240119-130050.604000 33MiB |
| 0 N/A N/A 887282 G ...sion,SpareRendererForSitePerProcess 110MiB |
| 0 N/A N/A 1080348 G /usr/lib/firefox/firefox 150MiB |
| 0 N/A N/A 1095402 G /usr/lib/thunderbird/thunderbird 7MiB |
| 0 N/A N/A 1106955 C+G ...ads/blender-3.6.8-linux-x64/blender 187MiB |
+---------------------------------------------------------------------------------------+

[Taichi] version 1.5.0, llvm 15.0.4, commit 7b885c2, linux, python 3.7.13

[Taichi] version 1.5.0, llvm 15.0.4, commit 7b885c2, linux, python 3.7.13
[Taichi] Starting on arch=x64

[Taichi] version 1.5.0, llvm 15.0.4, commit 7b885c2, linux, python 3.7.13
[Taichi] Starting on arch=opengl

[Taichi] version 1.5.0, llvm 15.0.4, commit 7b885c2, linux, python 3.7.13
[Taichi] Starting on arch=cuda

[Taichi] version 1.5.0, llvm 15.0.4, commit 7b885c2, linux, python 3.7.13

---

** Taichi Programming Language **

---

Docs: https://docs.taichi-lang.org/
GitHub: https://github.com/taichi-dev/taichi/
Forum: https://forum.taichi.graphics/

                               TAICHI EXAMPLES                                    

────────────────────────────────────────────────────────────────────────────────────
0: ad_gravity 25: laplace 50: physarum
1: circle_packing_image 26: laplace_equation 51: poisson_disk_sampling
2: comet 27: mandelbrot_zoom 52: print_offset
3: cornell_box 28: marching_squares 53: rasterizer
4: diff_sph 29: mass_spring_3d_ggui 54: regression
5: euler 30: mass_spring_game 55: sdf_renderer
6: explicit_activation 31: mass_spring_game_ggui 56: simple_derivative
7: export_mesh 32: mciso_advanced 57: simple_texture
8: export_ply 33: mgpcg 58: simple_uv
9: export_videos 34: mgpcg_advanced 59: snow_phaseField
10: fem128 35: minimal 60: stable_fluid
11: fem128_ggui 36: minimization 61: stable_fluid_ggui
12: fem99 37: mpm128 62: stable_fluid_graph
13: fractal 38: mpm128_ggui 63: taichi_bitmasked
14: fractal3d_ggui 39: mpm3d 64: taichi_dynamic
15: fullscreen 40: mpm3d_ggui 65: taichi_logo
16: game_of_life 41: mpm88 66: taichi_ngp
17: gui_image_io 42: mpm88_graph 67: taichi_sparse
18: gui_widgets 43: mpm99 68: texture_graph
19: implicit_fem 44: mpm_lagrangian_forces 69: tutorial
20: implicit_mass_spring 45: nbody 70: two_stream_instability
21: initial_value_problem 46: odop_solar 71: vortex_rings
22: jacobian 47: oit_renderer 72: waterwave
23: karman_vortex_street 48: patterns
24: keyboard 49: pbf2d
────────────────────────────────────────────────────────────────────────────────────
42
Running example minimal ...
[Taichi] Starting on arch=x64
42.0

Running time: 0.24s

Consider attaching this log when maintainers ask about system information.

Running time: 9.73s