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Author Topic: buildTiledModel() optimal parameters  (Read 374 times)

andrevall

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buildTiledModel() optimal parameters
« on: March 24, 2021, 01:39:29 PM »
Hello everyone,

when we build a Tiled Model from the GUI, the "Pixel Size" parameter is calculated automatically, and the "Face Count" parameter can be one of [High,Medium or Low].
I was wondering what are the equivalent parameters that we should pass to the  buildTiledModel() Python function? How can we calculate the pixel_size number automatically, as it is in the GUI, and set the face_count number so that it is equivalent to "High" in the GUI?

Thank you very much in advance,

Andrea
« Last Edit: March 24, 2021, 01:48:22 PM by andrevall »

Alexey Pasumansky

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Re: buildTiledModel() optimal parameters
« Reply #1 on: March 24, 2021, 08:50:56 PM »
Hello Andrea,

You can leave pixel_size undefined in order to use the default value.

Face count defines the number of polygons in each tile: Low - 4 000, Medium - 20 000, High 100 000. The default option is Low. Higher value is reasonable, if you are using larger tiles.
Best regards,
Alexey Pasumansky,
Agisoft LLC

andrevall

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Re: buildTiledModel() optimal parameters
« Reply #2 on: March 24, 2021, 10:20:23 PM »
Thank you Alexey,

that was really useful. I would also like to ask what is the purpose of the "keep_depth" parameter: if I try to use the function buildTiledModel() with depth maps as data source (source_data = Metashape.DataSource.DepthMapsData), I get the error "Null depth maps", so I guess we need to compute the depth maps manually before computing the tiled model, by using the buildDepthMaps() function
So, in this sense, what is the role of the "keep_depth" parameter in the buildTiledModel() function, since the depth maps have to be computed in advance?

Once again thank you very much,

Andrea
« Last Edit: March 24, 2021, 10:23:17 PM by andrevall »

Alexey Pasumansky

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Re: buildTiledModel() optimal parameters
« Reply #3 on: March 24, 2021, 10:25:29 PM »
Hello Andrea,

If you are using DepthMapsData as a source option for tilde model generation, the depth maps should be already present in the project, generated by buildDepthMaps command.

If you set keep_depth argument value to False, the depth maps will be removed from the project after completing the tiled model generation task.
Best regards,
Alexey Pasumansky,
Agisoft LLC

andrevall

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Re: buildTiledModel() optimal parameters
« Reply #4 on: March 24, 2021, 10:26:46 PM »
Thank you Alexey,

as always very helpful

bosscq

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Re: buildTiledModel() optimal parameters
« Reply #5 on: March 29, 2021, 09:11:48 AM »
Hello

if I don't pass pixel_size parameter,
I got "Exception: Zero resolution"
I started from importing external mesh.
then executed "chunk.buildTiledModel(source_data=Metashape.ModelData)"
any idea?

regards