Page 2 of 2

Re: Xbox Connect for 3D Cave Mapping?

PostPosted: Aug 17, 2011 10:48 am
by E-man
some thoughts i had;

seems to me that you need an algorithm to first flag the outliers as possible noise, and confirm statistically with repetition. this is assuming that the noise is consistent enough that you get pixel repetition between at least a few frames.

in regards to the tilt-shift issue, i would think the solution would be to represent a 3d model from each frame and have the computer align the models, not to align the frames to create the model. what i mean by this is that you take your point grid in x-y-z space and draw lines between your points. hopefully the grid is triangular instead of square, but even if it's square, you cut the squares in half to create isosceles right-triangles instead of equal-lateral triangles. next, with your 3d triangular grid, you draw a surface between each set of 3 points. this gives you a rough model from each frame. i don't know what the frame rate of the connect is, but i would imagine that most 2-3 ghz processors should be able to do this calculation in the latency between frames - if not, the point grid could just be recorded in buffer and calculated as processor power becomes available.
using this technique, two 3d surfaces in virtual space are aligned according to a statistical best fit, thereby aligning the frames, and the camera tilt-shift can easily be calculated between frames. with this information known, we know that the change in velocity and rotation between frames is likely small, assuming a reasonably high frame-rate, so we can estimate the tilt-shift of the following frame, thereby making the lining up of future surfaces easier because the computer has a better starting point to calculate the best-match orientation and position of the surfaces.
as several surfaces become lined up, it becomes easy to statistically average the surface - not point - positions, disregarding the outliers, and creating an accurate 3d map.

another option which should not be discounted, would be to physically attach an accelerometer or a device with an accelerometer in it such as an i-touch, to the connect, thereby calculating the tilt-shift directly. this could be done in conjunction with the surface modeling calculation to provide better predictive tilt-shift calculations and model synchronization.

another thought i had, as people talk about doing all this in real-time, is that you don't really need to do it in real-time for a cave survey. all you need to do is record the data along with a time-stamp, then you can let a more powerful computer sitting at home, plugged into ac power do all the heavy lifting.

if the connect were employed along with a traditional point-to-point survey, and you could push a button when the connect were at each survey station to denote the station along with a time stamp, you would have both an accurate 3d model and an accurate set of coordinates to align the survey to. the connect is going to negate sketching, but i think point-to-point is still important in assuring the model's accurate alignment to 3d space. i think we still have yet to find the perfect point survey technique and excitement about the connect should not deter people from advancing point survey equipment and techniques.

another thought i had while thinking about accelerometers, is if something like the i-touch would be accurate enough to create a point-to-point survey just by carrying it from station to station. i doubt that it is, considering all the movements it would have to make in traveling such a distance in a cave and the error level that would create, but if it were that accurate... bottle of whiteout and an i-touch for a one-person point survey. combine that with one person scanning the walls, ceiling, and floor for the 3d model, and could have a 3d cave model aligned to an accurate real world 3d space about as fast as you could explore. imagine the possibilities... 2 miles of mapped cave on one trip. :banana:

hope some of those ideas help in your development. i'm really excited about what's going on with all this and happy to help in any way that i can. i'm not great with computer languages and thus poor at writing software, but i'm good with concepts and making things in my workshop, so let me know if i can be of any assistance.

peace, eli

p.s. i apologize for the lack of capital letters. i'm writing this on my girlfriend's computer and the shift key does not appear to be working so well right now.

Re: Xbox Connect for 3D Cave Mapping?

PostPosted: Oct 24, 2011 11:33 am
by deltateam
Hi to all,

I'm new in this forum but i'm very interesed in help to develop the kinect 3d cave mapping.
also I wish to talk more close with William tucker who is more advance in the project, maybe if the cost of develop this is not so high, we can help with money and other things.

we are an non-profit ONG in mexico (Monterrey) for research environment, their name is Delta Team, A.C. so could be very good if we can do work it. also I see than William lives in Texas, so the state side of Nuevo Leon, we are close too.

I was starting learning more about it, i'm very exciting!

Re: Xbox Connect for 3D Cave Mapping?

PostPosted: Feb 27, 2014 11:24 am
by caver.adam
I'm curious. Has there been any papers or presentations on this? Software released? Thanks.

Re: Xbox Connect for 3D Cave Mapping?

PostPosted: Mar 12, 2014 5:04 am
by enexis
Hi all,

I just started to build one of that, my plan to finish in 3-4 week and give a test.
I'll keep you updated.

P.S. Any hint are welcomed!

Re: Xbox Connect for 3D Cave Mapping?

PostPosted: Jul 22, 2014 5:43 am
by csblinky
This is an older topic - but there are now several 3d mapping/scanning applications out there for the Kinect - the best seems to be from FARO - called SCENECT. There is another called SKANECT although it seems to be more for scanning rooms and such - it has some post processing features to make smoother 3d models. But FARO is a high end 3D surveying organization so their software will do closed loops (i.e. tunnels that loop back on themselves), etc - and it's free!! They also provide high end LIDAR type scanners for the surveying industry so reliable company. ... ps/scenect

One other device that came out recently is the Zebee or Zeb1 handheld mobile 3d scanner - different technology but interesting nonetheless.

Re: Xbox Connect for 3D Cave Mapping?

PostPosted: Jul 22, 2014 11:54 am
by rlboyce
Thanks for the links!

Re: Xbox Connect for 3D Cave Mapping?

PostPosted: Jul 25, 2014 6:09 pm
by caver.adam
Point Cloud Library (PCL) has some open source code available. But it is mostly designed to be an open source alternative to the microsoft developer kit. Also, the Xbox One sensor looks much more promising. Although it is still only accurate to about 14 feet on distance.