How to just show the origin color of .ply mesh

[tangjm24]

Here is the .ply mesh in MeshLab:

the first image is the original mesh with color, the second one is the rendered image using mitsuba3.

Here is my code:

import mitsuba as mi
mi.set_variant("scalar_rgb")
from mitsuba import ScalarTransform4f as T
import numpy as np


import trimesh

import drjit as dr
from drjit.auto import Float, Array3f, UInt 


scene_dict = {  
    'type': 'scene',  
 
    'integrator': {  
        'type': 'path'  
    },  

    'emitter': {  
        'type': 'envmap',  
        'filename': 'envmap.exr', 
        'scale': 1.0  
    },  

    'ply_object': {  
        'type': 'ply',  

        'filename':"\path\to\ply\file", 
        'filename':'fixed_inplace.ply',
        'face_normals': False,  
        'bsdf': {
             'type': 'diffuse',
             'reflectance': {
                 'type': 'mesh_attribute',
                 'name': 'vertex_color'
             }
         }
    },
}  



scene = mi.load_dict(scene_dict)  

w2c_gs = np.array(
    [[-0.94422938, -0.14619733,  0.2950546 , -1.89741043],
       [ 0.23149349,  0.34252699,  0.91054161, -2.45799736],
       [-0.23418292,  0.92806336, -0.28958032,  3.86228406],
       [ 0.        ,  0.        ,  0.        ,  1.        ]]
)
gs2mi = np.array(
    [[-1,0,0,0],
    [0,-1,0,0],
    [0,0,1,0],
    [0,0,0,1]]
)
w2c_mi = w2c_gs@gs2mi
# c2w = np.linalg.inv(w2c_mi)
to_world = T(w2c_mi)
print(to_world)
# sensor_count = 6

sensor: mi.Sensor = mi.load_dict({
    "type": "perspective",
    "fov": 34.36,
    "to_world": to_world,
    'film': {  
        'type': 'hdrfilm',  
        'width': 3950,  
        'height': 2968,  
        'rfilter': {'type': 'gaussian'},  
        'pixel_format': 'rgb',
        
    }, 
})


image = mi.render(scene, spp=64, sensor=sensor)
mi.util.write_bitmap('output.png', image)  

[merlinND]

Closing as duplicate of #1552 (reply in thread).
Please refrain from posting multiple times about the same issue.