Paper space omits GPS rover data

[Svenne]

Hi there,

I just started to check out QCAD 3.24.3 (on Ubuntu Mate 19.10 64bit) for it's potential use in our company and so far I'm pretty satisfied with the program. Very nice and clean design with a focus on the essentials. But here's the thing.

We are working with GPS data collected with a GNSS field rover, which of course produces X,Y,Z coordinates. This point and polyline data is then exported from the rover to a DXF file which then can be edited by us using a CAD program. In the end we have to deliver a DWG file to fit the specifications of our customer. And this DWG has to have the correct Z values for every measured point.
I know that QCAD is a 2D software and this is totally fine, since we never actually have to work in 3D. We just have to draw 2D maps, where the Z-value information has to be intact.

So far I tested this whole procedure and reopened the DWG file in BricsCAD to check if all the Z coordinates are still in place. Everything seems to work just fine. But there is one crucial thing which is not working:

In the model space everything is as it should be, but as soon as I switch into the paper space all the original GPS data (points and polylines) is gone / invisible. The only things left are text and objects which I've drawn manually. The odd thing is, when I copy one of those GPS polylines and past it back into the very layer I obtained it from, this clone object is visible in paper space. When I look at it's attributes they are all the same except for the Z value which differs for some reason. The same happens when I grab one of the anchor points of a line and place them somewhere else. Then the whole line object is visible in the paper space. Also when I move a measured point it appears on the paper view (with a z value of 0).

I don't know if I'm missing out on something, but I attached an example file for you to test. The circles were drawn by me manually to exemplify the problem. The same is true for the "Schnitt OK" object in the far left, which is a clone of the one to the right.

I assume this problem has something to do with the z values but I'm not really sure about that.

Thanks for the help!

[andrew]

Viewports indeed only render entities on the X/Y plane (2D).

This has been fixed for the next snapshot / release:
https://www.qcad.org/bugtracker/index.p ... sk_id=2065

[Svenne]

Wow that was a fast reply and fix. Thank you so much!

Btw. does that mean that QCAD automatically "flattens" the 3D objects for the plot. In BricsCAD/AutoCAD this is a step I always have to do manually when I want to plot a drawing.

When do you think the next snapshot / release will be available for download?

[andrew]

Btw. does that mean that QCAD automatically "flattens" the 3D objects for the plot.

For plotting, the Z coordinates are ignored. The drawing is not changed when plotting.

When do you think the next snapshot / release will be available for download?

A snapshot release (3.24.3.2) will be available in the coming says from the download link received after purchase.

[Svenne]

Thanks, that's awesome!

[andrew]

A snapshot release (3.24.3.2) is now available.

Note that snapshot releases are not intended for production use.

[Svenne]

Great to hear!

However, there is one more thing which is pretty crucial for us being able to work with QCAD:

You said that for plotting the z coordinates are ignored. Does that mean the length between two points is effectively plotted like the blue line in my example sketch?
Because that would be pretty bad for us and everyone who wants to draw a 2D plan from GPS data. For a correct plan we would need the real distances between two points / length of a line (red line in the sketch). Just ignoring the z-values without taking into account the real distances would lead to distortions especially in hilly terrain.

[andrew]

I'm not sure I understand.

A "plot" is a print out, typically on a piece of paper. It represents the view from the top which is 2 dimensional (X/Y). The distance between two points on paper is the distance between their respective X/Y coordinates (2D). Plots are 2D because paper is 2D.

A "dimension" is a label, typically with a dimensioning line and arrows. Dimensions are added to a drawing to indicate measurements on a drawing. This is intended for the viewer of the drawing to know the exact distance as it exists or has to be constructed in the real world.

Are you perhaps referring to dimensions (i.e. you want to add a label to the drawing, indicating the real (3D) distance between points)? If not, please elaborate.

[Svenne]

Sorry for the confusion, what I meant was:

In which way does "flatten" work when applied to 3D geometry to get a 2D plot? Is it like example "1." or "2." in the following sketch?
In "1." the distances A-B and B-C are smaller then they actually are because the terrain isn't taken into account.
In "2." however, the distances are correct i.e. the red A-B line has the same length as the blue A-B line.

[andrew]

It works in the 1st way (top view).