Low poly count in tiled model from imported model

[donclemento]

Hi

I imported some buildings of a city into Metashape and used the aerial photos to create a texture. That worked well as expected.
Now when I try to create the tiled model, i end up with way to few faces and the texture is blurry (see attached images).

I tried to fix the model in blender before import. Removed double faces, degenerate faces, merged vertices etc, checked normals etc.
Also tried with other file formats (3DS, OBJ, Collada, FBX). Checked bounding box etc. The texture could be generated, so the model is at the right place and Metashape somehow can read the triangle data.

Is that a limitation of Metashape, that models not created inside Metashape from depth maps or dense cloud cannot be converted into a tiled model?
I need to import these textured buildings into a Cesium web app.

Since this was not working, i also tried to transform the models in the export panel, but no success.

The source data and the project are in EPSG:2056.
I can provide the input data (3ds file) on request.

Any help is much appreciated.
Cheers

[Paulo]

Hola Don Clemento,

it occurs to me that this workaround could work:
from your model, create a block model (use Build Model... from model with split in blocks enabled). Generate texture from model and then you can export the block model in Cesium 3tz format.

[donclemento]

Hola Paulo!

Thank you very much for your quick reply.
I tried it. Unfortunaltely it does not look correct, it looks quite wild though

I forgot to mention in my initial post that i also tried the following functions in Tools --> Models:

• Decimate Model
• Smooth Model
• Close Holes

I did this because I feel like the model/faces/vertices are somehow not right and maybe Metashape will correct it then.
I also ran it trough FME Geometry Validator and tried with the fixed model. But nothing helped.

See the attached images for the model and the block model.

[Paulo]

Very strange Don,

could you give details or info of your textured model in  Metashape? Normally, you should be able to Build both block Model and Tiled model using model as source...

[donclemento]

Not sure what info I can provide.

I attached the model statistic and stangely, it has alot of errors even though FME and Blender said it was OK.
The model is a city model generated through classic photogrammetry in a CAD. It then got exported from that software (CityGRID from the company UVM) to 3DS and that's what I got from my customer.

I also tried with the LOD2 building models my government offers. I converted the DWG to a 3DS and got the same results in Metashape; the tiled model is corrupted. If it helps, I uploaded it here:
https://www.swisstransfer.com/d/f918ba0a-1546-4932-8561-07f11a86e359

I know the model is not perfect, but Metashape could still import it (and it looks good regarding geometries) and also could create the texture just fine.
I can provide the 3d file of my customer, but not publicly, I can send it to an email or so, if needed.

More and more customers want texturised models in my country, mostly cities and municipalities, so being able to do that in Metashape would be very nice.

Thanks for your effort,
cheers.


EDIT 1: I tried the "Fix topology" option in the model statisctic panel. That removed some faces but the tiled model and block model are still corrupted.
EDIT 2: Im on Metashape Professional, V2.2.0 build 19890
EDIT 3: When trying to create a block model with the data from the link above, I get "Empty model". The model is correctly georeferenced and the bounding box is big enough.

[Paulo]

Hola Don,

just imported your 3ds shared model into metashape and it imports correctly but only in Local Coordinates....(CS entry is greyed out). But clearly the coordinates System is CH103+. And even if I place 3 markers, scale bars and do Update transform...i get Not enough reference data! So measure tool is inactive and this happens even if I set markers reference to CH103+...

Something is fishy here! Hope support can provide some clarity1

[Alexey Pasumansky]

Hello!

If you are imported georeferenced mesh model to the empty chunk, please consider using the attached script (currently supports only DXF and OBJ formats).

It will ask to specify the coordinate system on input and will automatically assign it to the chunk and also will automatically calculate proper chunk.transform matrix.

Referencing the mesh model using markers is not possible in the current version, because markers do not support projections on mesh.

[Paulo]

Ciao Tazzo,

good news! It seems that with latest version (2.2.1), you can now generate a block model from an imported external 3DS model.

I imported your LOD2 model into MS and then use Build Model... using from model Data source.

I then get a block model divided into many tiles. Then select Block Model and use Export tiled model from context menu.

You can then select Cesium 3tz format...