Rework importing into geo nodes

[aafkegros]

Moves to Import nodes
Also will move normalization into geo nodes for 5.0
Removes cache collection
This will be #149 chunk-compatible still, although chunks might need a more programmatically created node group
Final Volume object will be a multi-grid volume (with materials no longer explicitly set as nodes but just listed in Object Materials)

something like this

Also optionally:
move to Import OBJ for labelmasks with this system - would also remove the dependency on Blender to write out files. - I'll still look at how to organize cell_id attributes on the fly

[aafkegros]

• this needs a boolean input that defines whether to normalize to 0 - 1 range or remap back to original values

still thinking of good names for that

[BradyAJohnston]

I know you are doing other (more important) things right now but I was cleaning out my GH notifications so I thought I would post here for later. I've been developing a system for code-defined node trees for a few weeks now and after years of trying out other solutions and failing to build one myself I finally have a good package for defining and building them that I am going to be switching MN over to start using soon: https://github.com/BradyAJohnston/nodebpy

def import_channel():
    string_to_format = "{base_path}/{scale}/x0y0z0/x0y0z0c0t{time:04}.vdb"

    with TreeBuilder("Channel Import") as tree:
        with tree.inputs:
            base_path = s.SocketString("base_path", subtype="FILE_PATH")
            time = s.SocketInt("Time")
            channel_number = s.SocketInt("Channel Number")
            channel_name = s.SocketString("Channel Name")
            min_value = s.SocketFloat("Minimum Value")
            max_value = s.SocketFloat("Maximum Value")

        string = n.FormatString(
            time=time,
            channel_number=channel_number,
            base_path=base_path,
            scale=n.Integer(0),
            format=string_to_format,
        )
        gng = n.GetNamedGrid(n.ImportVDB(string), name="data")
        sng = n.StoreNamedGrid(
            gng,
            name=channel_name,
            grid=(gng.o_grid - min_value) / (max_value - min_value),
        )
        with tree.outputs:
            _ = sng >> s.SocketGeometry("Volume")

    return tree.tree

[aafkegros]

Looks great! I will see how much i'll switch to it immediately, but this looks like a definite way forward!

[BradyAJohnston]

Still early days for it - so open to design suggestions!