How to build a holodeck, week 37

I’ve made good progress on the networking this week - I’ve got four devices all feeding point clouds into the same data set (two Kinect cameras, two Tango tablets). They are not aligned yet - that’s one of the three remaining big chunks of work before this is a product.

I’ve also got the first pass of a Kinect texture feed running - not over the network yet, just locally.


Week 37 - pointclouds from four devices

I spent a few days trying to figure out why I was having problems receiving multiple point clouds from different sources - all the code looked like it should be working properly, but when I turned on my primary feed (the local kinect) the network kinect feed stopped updating. Turns out, I was using an accumulated value to sort the meshing priority, and the local feed was accumulating at around ten times the rate of the network feed, so the network feed never got a look in for meshing chunks.

Once I fixed that up (which involved a load of digging around code I wrote a few months ago, so it took a lot longer than I expected) I now have four working pointcloud feeds - three from the network and one locally.

The Kinect colour feed is working locally now - I need to get this sent over the network too, and I also need to get the Tango colour feed sent over the network, and then I can start using that to texture the mesh I’m generating. Small steps here, but it looks to be pretty fast grabbing the texture (unlike the Tango!) and hopefully I can compress it up enough to still get a decent result being sent over the network. Each Kinect colour frame is 1920 * 1080, 24 bit - so about 6 meg uncompressed. I can definitely drop the res (probably to 512 * 512) and there’s a variety of compression options I can look at, so hopefully I can get this down to 30-40K per frame while still retaining a decent amount of quality.

Lots to do! Hopefully next week will be nice and productive.

On a personal note, my carpal tunnel is back. The frailty of human flesh is really starting to annoy the hell out of me - once Tesla release a robot spider body, I’ll be at the front of the queue.

Until next week!

Written on November 5, 2016