SVX format, unexpected results

Apologies if this is the wrong forum area to post in: if anyone can suggest a better place I'll happily move it over.

I've been experimenting with the new SVX voxel format that uses PNG slides to define a model:

https://www.shapeways.com/blog/archives/17972-shapeways-laun ches-svx-voxel-file-format-for-3d-printing.html

When I upload SVX files to Shapeways I'm getting some unexpected results. The easiest way to explain it is probably using some examples, so here are three files I've used for testing:

1. Spherical spiral: https://www.flypig.org.uk/vapour/public.php?service=files&am p;t=fdc68ed957862694d145c5277edf29a4
2. Sine wave: https://www.flypig.org.uk/vapour/public.php?service=files&am p;t=e417ec9662ce0aeece1eacbda4fa99c5
3. Combined: https://www.flypig.org.uk/vapour/public.php?service=files&am p;t=c8e162ab2d14a9b90086954b1b78199c

And here are links to the resulting renders on Shapeways:

1. https://shpws.me/wkQm
2. https://shpws.me/wlq0
3. https://shpws.me/wkRT

Finally, here are STL versions of the objects for reference:

1. https://www.flypig.org.uk/vapour/public.php?service=files&am p;t=988b9402c0beafc19a77a4d9abef6aa0
2. https://www.flypig.org.uk/vapour/public.php?service=files&am p;t=087523b0b3143b3a37e1b336506a1c7a
3. https://www.flypig.org.uk/vapour/public.php?service=files&am p;t=2ea12a7beb238425fcd92a271fba36cc

For some reason, models 2 and 3 aren't matching what I'm expecting: there's a whole section chopped out from the middle of each model. Model 1 is complete, but the SVX version is stretched vertically (along the Z axis). The format is new to me, so I'm quite expecting this to be an error in the way I'm generated the files. However, manual inspection of the SVX files (using a PNG viewer) doesn't show any obvious problems to me.

Unfortunately I don't have any other software to compare against, so I'm keen to know whether this is a problem with the files, or the way Shapeways is importing them. If anyone has any insight into this I'd be very grateful!

Sorry for replying to my own post. After a bit more experimentation it does look like this may be an issue with the way Shapeways is interpreting the files.

The attached file Flat.svx is just a single block of material like this:



Once uploaded it results in a pair of planes, presumably the boundary planes of the block: https://shpws.me/wnTQ

I tried a different file with a single pixel border around the solid area, like this:



Uploading the model gives the expected result: https://shpws.me/wnUN

It looks like it may just be a case of the vertically aligned boundary planes being cropped if they're up against the edge of the bounding box. If this is a bug and I'm not just confused by the file format, what's the best way to bring it to Shapeways's attention?