Transmit raw vertex information to XTK?

Question

We're using XTK to display data processed and created on a server. In our particular case, it's a parallel isocontouring application. As it currently stands we're converting to the (textual) VTK format and passing the entire (imaginary) VTK file over the wire to the client, where XTK renders it. This provides some substantial overhead, as the text format outweighs in the in-memory format by a considerably amount.

Is there a recommended mechanism available for transmitting binary data directly, either through an alternate format that is well-described or by constructing XTK primitives inside the JavaScript code itself?

Answer 1

It should be supported to parse an X.object from JSON. So you could generate the JSON on the serverside and use the X.object(jsonobject) copy constructor to safe down cast it. This should also give the advantage that the objects can be 'webgl-ready' and do not require any clientside parsing which should result in instant loading.

I was planning to play with that myself soon but if you get anything to work, please let us know.

Just have in mind that you need to match the X.object structure even in JSON. The best way to see what is expected by xtk is to JSON.stringify a webgl-ready X.object.

Answer 2

XMLHTTPRequest, in its second specification (the last one), allows trans-domain http requests (but you must have the control of the php header on the server side).

In addition it allows to sent ArrayBuffer, or Blobs or Documents (look here). And then on the client side you can write your own parser for that blob or (I think it fits more in you case) that BinaryBuffer using binary buffer views (see doc here). However XMLHTTPRequest is from client to server, but look HTML5 WebSocket, it seems it can transfert binaryArrays too (they say it here : ).

In every case you will need a parser to transform binary to string or to X.object at the client side.

I wish it helped you.