Can't uncompress tile when splitting into chunks

[GalDa]

Also posted here: https://github.com/agisoft-llc/metashape-scripts/issues/119

Hi there,

I'm working on generating a very large tiled model composed of thousands of images. To manage this, I'm following the logic used in the

Code: [Select]

split_in_chunks_dialog.py script, with an additional step to divide the tiled model generation as well. This is necessary because attempting to build a tiled model from a single, large merged model consistently results in a "bad allocation" error due to insufficient memory.

To handle this, I’m building one tiled model per chunk. I use the operand_chunk to merge previously built valid tiled models into the current one.

This approach generally works, but occasionally I encounter the error: "Can't uncompress tile", and the older tiled models fail to merge into the current one, even though they were built successfully. It doesn't appear to be a performance issue, and I'm unsure what’s causing the failure.

Below is the relevant portion of the code that's failing:

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if operand_chunk.tiled_model:  # If the previous chunk has a tiled model to merge
    new_chunk.buildTiledModel(
        tile_size=256,
        pixel_size=GSD,
        source_data=Metashape.DataSource.ModelData,
        face_count=20000,
        transfer_texture=True,
        ghosting_filter=False,
        merge=True,
        operand_chunk=operand_chunk.key,
        progress=progress_print)
else:  # This is the first tiled model to be created
    new_chunk.buildTiledModel(
        tile_size=256,
        pixel_size=GSD,
        source_data=Metashape.DataSource.ModelData,
        face_count=20000,
        transfer_texture=True,
        ghosting_filter=False,
        progress=progress_print)

if new_chunk.tiled_model:  # Check if the tiled model was created successfully
    valid_index = index  # Update the valid index to the latest chunk with a tiled model
    operand_chunk = doc.chunks[valid_index]  # Update the operand_chunk

Note: GSD is calculated earlier and is approximately 0.03.

Do you have any insights into what might be causing the "Can't uncompress tile" error? I am sure it get's the right

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operand_chunk.key.
a partial log showing the error for reference is attached.


Environment:
- Metashape Python SDK: 2.2.0
- CPU: Intel® Core™ i9-14900
- GPU: NVIDIA GeForce RTX 4070 (not overclocked)
-  RAM: 32 GB
-  OS: Windows 11 (23H2)


Thanks in advance for your help!

[Alexey Pasumansky]

Hello GalDa,

Can you please confirm, that the issue is fixed in the latest 2.2.1 version?

[GalDa]

Yes, fixed in 2.2.1