How to export mesh for round trip to 3ds Max AND back?

[maddin]

I tried several options for exporting the PhotoScan mesh to 3ds Max for post-processing and then bringing it back to PhotoScan but so far have failed to keep the mesh in it's original position/orientation.

I need to export to FBX in order to keep the camera information. Using local coordinates, the mesh will not show up where it was in PhotoScan upon re-import; using WGS coordinates, all I get in 3ds Max 2014 is all vertices in one line.

Could someone please clarify the individual steps needed to export a mesh from PhotoScan to 3ds Max for modification, followed by an export from 3ds Max and re-import into PhotoScan?

Thanks!
Martin

[maddin]

I tried several options for exporting the PhotoScan mesh to 3ds Max for post-processing and then bringing it back to PhotoScan but so far have failed to keep the mesh in it's original position/orientation.

I need to export to FBX in order to keep the camera information. Using local coordinates, the mesh will not show up where it was in PhotoScan upon re-import; using WGS coordinates, all I get in 3ds Max 2014 is all vertices in one line.

Could someone please clarify the individual steps needed to export a mesh from PhotoScan to 3ds Max for modification, followed by an export from 3ds Max and re-import into PhotoScan?

Thanks!
Martin

*bump*

Anyone?

Just read the manual again cover to cover and could not find any specifics on this topic, just general references that it is possible to manually process the mesh in 3rd party applications.

Thanks!
Martin

[Alexey Pasumansky]

Hello Martin,

When you export model in WGS84 the units are different by x and y axis (since there are in degrees), try exporting in local coordinates.

[maddin]

When you export model in WGS84 the units are different by x and y axis (since there are in degrees), try exporting in local coordinates.

Thanks, that makes sense. I am also having other problems with FBX, as reported here: http://www.agisoft.ru/forum/index.php?topic=1738.0

So some step-by-step instructions how to get the mesh into 3ds Max and back would be much appreciated.

Cheers
Martin

[maddin]

So some step-by-step instructions how to get the mesh into 3ds Max and back would be much appreciated.

Anyone? I am sure someone must have done it before, no?
I want to export the mesh in order to do some mesh repairs I cannot do in PhotoScan as well as computing my own UVs; then I need to go back into PhotoScan in order to bake my texture from the camera projections.

Thanks in advance
Martin

[Wishgranter]

Maddin, would recommend for this stuff to start learn Zbrush or MUDBOX.... 3DS max is best at "rendering" stuff out, not so good for repairing  mesh....

[maddin]

Maddin, would recommend for this stuff to start learn Zbrush or MUDBOX.... 3DS max is best at "rendering" stuff out, not so good for repairing  mesh....

So how do I get the mesh into Mudbox and back again into PhotoScan?

-- MartinB

[Wishgranter]

Import OBJ
Export OBJ

Don?t rotate, resize, move theobject inside MUDBOX or Zbrush

 

[Alexey Pasumansky]

Hello Martin,

I think you should follow Wishgranter's recommendations. I also suggest that you should use Local Coordiantes in both Export/Import Model dialogs. Note that models from only PLY and OBJ formats can be imported back to PhotoScan.

Let us know if you succeed.

[maddin]

The problem with that suggestion is that OBJ export from PhotoScan is extremely slow for large (20 Mio. faces) meshes when compared to PLY, by an order of ten or more.

I found 3rd party PLY importer plugins for 3ds Max and Mudbox but none for export.
So right now, I am exporting from PS as .ply format, import that into 3ds Max, post-process the mesh/UVs, then export from 3ds Max as .obj and re-import into PS for projecting/blending the textures.

None of this works for camera data, which can only be exported through FBX, which causes 3ds Max to rotate and scale the mesh because of incorrect data in the FBX. I can probably figure out how to compensate for this transformation, but I was curious to hear how this is supposed to work officially.

Martin

[Alexey Pasumansky]

Hello Martin,

OBJ export is slow via network, you can try to export on a local drive.
Cameras are not stored in OBJ and PLY formats.

These problems with FBX export sounds strange, probably you can send us a sample dataset with some screenshot illustrations?

[maddin]

OBJ export is slow via network, you can try to export on a local drive.

I have all my data on an USB3-attached drive, no network involved. All other file operations on that disk perform just like my internal disc.

It is to be expected that OBJ, being an ASCII format, is slower than binary PLY but still the performance difference is very big. I will post some numbers soon.

These problems with FBX export sounds strange, probably you can send us a sample dataset with some screenshot illustrations?

Sure, where should I send these?

The problem are mainly that PS flags FBX with y-Up coordinate system whereas the data is actually stored z-Up. This causes a rotation, since 3ds Max is z-Up. The scaling is caused by some unit parameter in the FBX file, I believe.

Martin

[Alexey Pasumansky]

Martin,

You can send problematic data to support@agisoft.ru.

[Wishgranter]

if remeber you can flip teh axis when exporting  the data from 3ds max....