Same parameter and different results
Tue, 04/24/2018 - 02:43
Hi,
I tried the same object with almost the same parameters and got different results. Here's what I did:
1. an object called 1.obj
2. try parameter -sx 1, got result of 4 faces
3. try parameter -sx 1 -v 480, got result of so many faces
I read the document and it says that "-v 480" is the default parameter when using "-sx N". So .. what went wrong?
Here's the log for "-sx 1":
C:\decimon-test>decimon 1.obj -sx 1
Qt: Untested Windows version 6.2 detected!
mtl Importer error:
cannot open input file: 1.mtl
Loading '1.obj': done in 0.02 sec
'1.obj' properties:
Number of independent meshes: 1
Total number of vertices: 6376
Total number of faces: 8494
Bounding box size: [699, 1.74, 0.776], Extent: [699.01]
Simplifying the model to satisfy 1 pixel(s) tolerance relatively to 480 x 480 viewport...
... done in 0.04 sec with 4 resulting faces
Saving 'res.obj': done in 0.01 sec
Summary:
Input model: 8494 faces, loading time: 0.02 sec
Simplification time: 0.04 sec
Output model: 4 faces, saving time: 0.01 sec
Total time: 0.08 sec
And here's the log for "-sx 1 -v 480"
C:\decimon-test>decimon 1.obj -sx 1 -v 480
Qt: Untested Windows version 6.2 detected!
mtl Importer error:
cannot open input file: 1.mtl
Loading '1.obj': done in 0.04 sec
'1.obj' properties:
Number of independent meshes: 1
Total number of vertices: 6376
Total number of faces: 8494
Bounding box size: [699, 1.74, 0.776], Extent: [699.01]
Simplifying the model to satisfy 1 pixel(s) tolerance relatively to 480 x 480 viewport...
... done in 0.01 sec with 8416 resulting faces
Saving 'res.obj': done in 0.07 sec
Summary:
Input model: 8494 faces, loading time: 0.04 sec
Simplification time: 0.01 sec
Output model: 8416 faces, saving time: 0.07 sec
Total time: 0.12 sec
Logs also show that the viewport is adjusted to 480*480 under both circumstances. So ... any help? Thanks!
Wed, 04/25/2018 - 01:27
#2
Thanks for your helpful reply! And by the way, in order to avoid adding "-v" parameter, I linearly scaled the sx number to adjust to the 480*480 viewport, yet I'm not totally sure the scaling method is equivalent to its original parameters.
For example, I would like to use "-sx 2 -v 960", and I use "-sx 1" instead. Are the 2 groups of parameters equivalent? I tested and the result shows they are indeed equivalent, just want to be sure of it 
Wed, 04/25/2018 - 19:44
#3
You are right. Using option "-sx 1" is equivalent to "-sx 2 -v 960". For fine tuning, you can also use -sx option with a floating point number, e.g. "-sx 1.5" or "-sx 2.3".
Hi Wangyang,
Thank you for your question and for the detailed report.
We have successfully reproduced and fixed the problem.
In the current version, -v option always turns on (by mistake) -b option (boundary preservation).
We will release the fix within the upcoming minor release as soon as possible.