Change the ratio but output file don't change

[ahmedsaptan]

I try to minimize file with 0.1 but it output the same file with 0.2 to 0.06

[neurolabusc]

Unable to replicate. Can you provide an example? Does your mesh have enough complexity to support the desired reduction granularity? The example below provides a complete demonstration of successful compression to both 0.2 and 0.06 ratios using the included bunny.obj image:

$git clone https://github.com/neurolabusc/Fast-Quadric-Mesh-Simplification-Pascal-.git
$cd Fast-Quadric-Mesh-Simplification-Pascal-/c_code/
$g++ Main.cpp -O3 -o simplify
$./simplify ../bunny.obj bunny02 0.2
Mesh Simplification (C)2014 by Sven Forstmann in 2014, MIT License (64-bit)
Input: 34834 vertices, 69664 triangles (target 13933)
iteration 0 - triangles 69664 threshold 2.187e-06
Output: 6967 vertices, 13930 triangles (0.199960 reduction; 0.0779 sec)
$./simplify ../bunny.obj bunny006  0.06
Mesh Simplification (C)2014 by Sven Forstmann in 2014, MIT License (64-bit)
Input: 34834 vertices, 69664 triangles (target 4180)
iteration 0 - triangles 69664 threshold 2.187e-06
iteration 5 - triangles 7572 threshold 0.00209715
Output: 2091 vertices, 4178 triangles (0.059974 reduction; 0.1101 sec)

[neurolabusc]

Here is an example using the Pascal code showing similar performance:

$git clone https://github.com/neurolabusc/Fast-Quadric-Mesh-Simplification-Pascal-.git
$cd Fast-Quadric-Mesh-Simplification-Pascal-
$fpc simplify
$./simplify bunny.obj bunny02 0.2
Mesh Simplification (C)2014 by Sven Forstmann, MIT License 64-bit
 simplify bunny.obj with ratio = 0.20, agressiveness = 3.00 and tol = 0.00000
 Input: 34834 vertices, 69664 triangles
 Output: 6968 vertices, 13932 triangles (0.200, 0.21sec)
  Creating file bunny02
$./simplify bunny.obj bunny006  0.06
Mesh Simplification (C)2014 by Sven Forstmann, MIT License 64-bit
 simplify bunny.obj with ratio = 0.06, agressiveness = 3.00 and tol = 0.00000
 Input: 34834 vertices, 69664 triangles
 Output: 2092 vertices, 4180 triangles (0.060, 0.21sec)
  Creating file bunny006

[ahmedsaptan]

./simplify '/home/moman/test of ismile/Upper/P-003 Upper jaw - 13 - Model.obj' obj02 0.2
Mesh Simplification (C)2014 by Sven Forstmann in 2014, MIT License (64-bit)
Input: 613116 vertices, 1226220 triangles (target 245244)
iteration 0 - triangles 1226220 threshold 2.187e-06
iteration 5 - triangles 816590 threshold 0.00209715
iteration 10 - triangles 773134 threshold 0.0627485
iteration 15 - triangles 765398 threshold 0.61222
iteration 20 - triangles 762754 threshold 3.40483
iteration 25 - triangles 761252 threshold 13.4929
iteration 30 - triangles 760368 threshold 42.6184
iteration 35 - triangles 759778 threshold 114.416
iteration 40 - triangles 759426 threshold 271.819
iteration 45 - triangles 759216 threshold 587.068
iteration 50 - triangles 759042 threshold 1174.71
iteration 55 - triangles 758846 threshold 2207.98
iteration 60 - triangles 758648 threshold 3938.98
iteration 65 - triangles 758542 threshold 6722.99
iteration 70 - triangles 758470 threshold 11047.4
iteration 75 - triangles 758404 threshold 17565.6
iteration 80 - triangles 758352 threshold 27136.1
iteration 85 - triangles 758308 threshold 40867.6
iteration 90 - triangles 758276 threshold 60170.1
iteration 95 - triangles 758276 threshold 86812.6
Output: 378667 vertices, 757316 triangles (0.617602 reduction; 95.8634 sec)

[ahmedsaptan]

./simplify '/home/moman/test of ismile/Upper/P-003 Upper jaw - 13 - Model.obj' obj0.06 0.06
Mesh Simplification (C)2014 by Sven Forstmann in 2014, MIT License (64-bit)
Input: 613116 vertices, 1226220 triangles (target 73573)
iteration 0 - triangles 1226220 threshold 2.187e-06
iteration 5 - triangles 816590 threshold 0.00209715
iteration 10 - triangles 773134 threshold 0.0627485
iteration 15 - triangles 765398 threshold 0.61222
iteration 20 - triangles 762754 threshold 3.40483
iteration 25 - triangles 761252 threshold 13.4929
iteration 30 - triangles 760368 threshold 42.6184
iteration 35 - triangles 759778 threshold 114.416
iteration 40 - triangles 759426 threshold 271.819
iteration 45 - triangles 759216 threshold 587.068
iteration 50 - triangles 759042 threshold 1174.71
iteration 55 - triangles 758846 threshold 2207.98
iteration 60 - triangles 758648 threshold 3938.98
iteration 65 - triangles 758542 threshold 6722.99
iteration 70 - triangles 758470 threshold 11047.4
iteration 75 - triangles 758404 threshold 17565.6
iteration 80 - triangles 758352 threshold 27136.1
iteration 85 - triangles 758308 threshold 40867.6
iteration 90 - triangles 758276 threshold 60170.1
iteration 95 - triangles 758276 threshold 86812.6
Output: 378667 vertices, 757316 triangles (0.617602 reduction; 94.3381 sec)

[neurolabusc]

I suspect that your mesh is not a manifold surface but has lots of holes/gaps/tears in it. This will make simplification difficult and high resolution images will illustrate these errrors in the original mesh:

What tool created the upper jaw model? If you created this from a voxelwise imaging dataset, make sure to use a marching cubes method that does not create a lot of tiny gaps. For example Surfice has the Advanced/ConvertVoxelwiseVolumeToMesh menu item. The MeshLab CleaningAndRepairing/MergeCloseSurfaces might help. My biggest fear is if the software that created this did a poor job merging vertices it may also have done a poor job of ensuring consistent face normals.

In general, good simplification requires a well designed input image. So I fear you really want to go back to your mesh creation and make sure you are using a good algorithm. Here is an elegant implementation - just make sure to include a tiny tolerance for vertex location to handle rounding errrors.

As a Hail Mary, you could try compiling the Pascal version of this repository and set the tolerance to a value greater than 0.0.:

Mesh Simplification (C)2014 by Sven Forstmann, MIT License 64-bit
Usage: ./simplify <input> <output> <ratio> <agressiveness> <tolerance>
 Input: name of existing MZ3 or OBJ format mesh
 Output: name for decimated MZ3 or OBJ format mesh
 Ratio: (default = 0.2) for example 0.1 will decimate 90% of triangles
         A ratio of 1 is "lossless" (though beware of pole artifacts) 
         A ratio of 2 only removes repeated vertices
         A ratio of 3 only removes of replicated vertices and faces (slow)
         A ratio of 4 makes no change (file conversion only)
 Agressiveness: (default = 3.0) faster (9) or better decimation (1)
 Tolerance: (default = 0.0) vertices closer to each other than this distance will be merged

So the call might be:

./simplify '/home/moman/test of ismile/Upper/P-003 Upper jaw - 13 - Model.obj' obj0.06 0.06 3 0.01

If you like the result, you could port the Pascal code to C for the vertex merging (also referred to as vertex welding).