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I have been using OpenVDS for a while to read 3d seismic data and I have accumulated several questions. My apologies if I did not read the documentation closely enough.

What is DimensionsND and DimensionsGroup?

I suspect that DimensionsND is OpenVDS, DimensionsGroup is the corresponding VDS type. That doesn't help me much because I don't really understand why either is needed. It looks to be that these are enums used to extract e.g. 3d data from a 4d, 5d, or 6d cube by skipping some dimensions but not re-ordering or transposing them.

DimensionsND extracts two or three dimensions, e.g. Dimensions_01 or Dimensions_012. DimensionsGroup extracts 1 to all 6 dimensions.

But why are these needed at all when I read data? If skipping a dimension, why not set min==max instead for the "constant" indices and min=max=0 for the unused ones?

Can you confirm the following: If I want to read a 3d sub-cube from a 3d dataset, i.e. layout->GetDimensionality()==3, then DimensionsND can only be Dimensions_012 when i want to read a sub-cube.

How can I handle OpenVDS files having more that three dimensions, that are really just multiple 3d cubes packed together with the fourth dimension being the cube number? I suspect the answer to the previous question might shed some light in this.

What is a multi-component file?

And how should it be handled? Is this the same as a 4d cube or is this a different feature?

What is ProduceStatus?

Can you confirm that I can ignore this when reading full resolution data? I am guessing that "Unavailable" tells me I might get an error later and the difference between "Normal" and "Remapped" is I suspect just a hint about the cost. I am also guessing that Remapped is only relevant for LOD > 0.