Not so smart cursor

[Anonymous]

I am probably doing something wrong

As I am drafting, lets say adding a point on a roof, when the cursor changes, I click and move on to the next point, only later to find that the node put down is off the edge of the wall or whatever I was trying to hit by a tiny amount, only noticable if one zooms in very far. This ends up being a problem later on and very annoying.

What can I do to stop this besides zooming way in every time I click?

Thanks

[TomWaltz]

Make sure you have a "mercedes" cursor before you click to place the new point.

Also, make sure no one moved the wall on you 😉 (more common problem in Teamwork projects)

[Gerald Hoffman]

It also could be a rounding problem. I work in Imperial measure and to best accuracy but find that even when you snap to cursor indications it is precise only to a certain degree. If I zoom in as far as possible there are all kinds of elements that are off by a small amount which measure at exactly the same number. The non-alignment is less than 1/64". In other words you can zoom in closer than the accuracy factor. I think if you put an element at 16'-8" away from another it will be 16.66667' ( I don't know how many decimals) converted from metric.

I think there was a discussion on this a long time ago but cant' remember much about it. Someone please correct me if I am wrong here.

Thanks,

[TomWaltz]

It just hit me, it could also be that the snap grid is turned on. That would cause the point to move from where you expected.

I think Archicad is supposed to be accurate to 0.1 millimeter, which is 0.00039370079", or approximately 1/2560"

[Anonymous]

Mo,

There are many possible causes for slight inaccuracies, but the cursor will always snap precisely to the node or edge when so indicated by its shape. The possibilities are:

1. Too many nodes or edges close together. This can occur when the model is very detailed or as a result of sloppy drafting.

2. Drifting off the snap just as you click. This can be caused by an oversensitive mouse or having the snap range set too small (on a high res monitor 2-3 pixels may be to low, 4-5 is probably better).

3. Snapping to ghost story elements that are slightly misaligned.

Building models require a much higher degree of discipline and accuracy than in 2D drafting, so it is very important always to constrain to precise angles, enter known values numerically and be sure to snap only to accurately drawn points and edges. This can often be difficult to maintain as the model gets stretched and tweaked around in the design phases.


Gerald,

Rounding errors only come up in dimensioning or if you try to use the coordinates palette display for accurate measurements. It is true that the palette only displays down to 1/64" or 0.1mm accuracy but this only becomes a problem if you rely on these numbers to be precise. As Tom points out the internal accuracy of the program is much higher.

To avoid these sort of problems I always constrain angles (shift or option/alt + a) and type in dimensions (x, y, r, a, etc.) at reasonable units of accuracy (I try to keep to whole feet/dm or inches/cm whenever possible. This way when 64ths of inches or 10ths of mm show up in the coordinates palette I know I have a problem.


BTW, Tom, I think your arithmetic is off:

0.1mm = 1/254" = 0.00394"

But I believe the internal accuracy is at least 0.001mm.

[Gorazd]

I have run into another inaccuracy which is quite annoying. Can please somebody try to do the following and confirm to me, that I am not doing anything wrong.

Draw a vertical line, select it, then take your hand of the mouse an just type:
CRTL+SHIFT+D (copy)
ENTER (to confirm starting point)
X
100+
ENTER

This should copy a line 100 cm away of the first one.

Repeat the process several times.

Measure the distance between the lines. Some lines are not 100 cm away from the second one. This happens if I zoom out. If I move the mouse a little, or have a big zoom, distances are OK.

[Anonymous]

Gorazd wrote:

Draw a vertical line, select it, then take your hand of the mouse an just type:
CRTL+SHIFT+D (copy)
ENTER (to confirm starting point)
X
100+
ENTER

This should copy a line 100 cm away of the first one.

Repeat the process several times.

Measure the distance between the lines. Some lines are not 100 cm away from the second one. This happens if I zoom out. If I move the mouse a little, or have a big zoom, distances are OK.

Just tried it quite a few times, with different measurements, worked every time for me. I'm working in metric, using millimeters...

[Link]

Draw a vertical line, select it, then take your hand of the mouse an just type:
CRTL+SHIFT+D (copy)
ENTER (to confirm starting point)
X
100+
ENTER

This should copy a line 100 cm away of the first one.

No it shouldn't actually. It will copy a line 100 in the X direction, because that is all you have entered. But you didn't enter anything for Y, so whatever Y was reading in your coordinate box when you hit the last enter is how far it will move in the Y direction. You must enter both X and Y. This is a good example of why you should change your method to something like this:

Click and hold on the selected element(s) and start dragging (the pet palette should default to drag - if not change it to);
Hit ctrl/cmd for a copy (or alt+ctrl/opt+cmd for multiple copies);
Drag mouse in general direction to copy;
Hold shift down (to snap it to the mouse constraints - as set in Work Environment...Mouse Constraints & Methods) and hit the R key (just once)
100
ENTER

This can be used for any direction and you don't need to enter the Y coordinate. You can also let go of shift or hit R again and reset your angle on the fly for different angles. In AC10 the R can be replaced with a D for distance (unless of course you are using surveyor's units and D becomes degrees ).

Hope that helps.

Cheers,
Link.

[Gorazd]

I know that I will have to change this method of copying objects, but sometimes, fingers are faster than my head, and ooops , I did it again. It is strange anyway that even if I dont touch the mouse at all, after hiting Enter for the first point in Distance field in tracker there is some value other than zero.

Thank you for trying this.