Modeling
About Archicad's design tools, element connections, modeling concepts, etc.

Units accuracy

Tom Krowka
Enthusiast
I'm having a discussion with my coworker about the accuracy of the units and the effect on the drawing. He likes to use three or four decimal places of accuracy; he feels that otherwise the drawing elements, walls, roofs, etc. don't really line up on top of each other, and this causes display problems with the model and elevations. Sometimes it seems that when the drawing is zoomed, you can't get points to line up right over each other. Or it's extremely difficult.

I think it has something to do with the pixels and where each point actually is.

I like to keep mine set to one decimal place or 1/8", but I don't seem to have as many problems. Or maybe I do but it's lousy drawing technique.

Anyway, which setting is commonly used, and does it make any difference?

As always, thanks
Tom Krowka Architect
Windows 11, AC Version 26
Thomas@wkarchwk.com
www.walshkrowka.com
23 REPLIES 23
Anonymous
Not applicable
Tom wrote:
When it's zoomed in close, the actual points of the intersection of the lines or whatever it is do not stack up one on top of the other no matter what the settings are.
I have encountered numerous instances where I was placing an element and I saw the dark check-mark cursor when I clicked, but upon closer inspection, it didn't grab the hotspot and my placed element was wrong. I've become so paranoid about this that I am now in the habit of zooming way in on hotspot areas for every click -- certainly a waste of time, but less of a waste that accidentally drawing something wrong. By the way, my cursor snap range is set to 3.
Tom Krowka
Enthusiast
have encountered numerous instances where I was placing an element and I saw the dark check-mark cursor when I clicked, but upon closer inspection, it didn't grab the hotspot and my placed element was wrong. I've become so paranoid about this that I am now in the habit of zooming way in on hotspot areas for every click -- certainly a waste of time, but less of a waste that accidentally drawing something wrong. By the way, my cursor snap range is set to 3.
That's what I'm talkin about. The checkmark really does not mean you are on that point. Wouldn't it be better to set your cursor snap range to 1. In my mind, that would give you the most accuracy. But no matter what I set the accuracy of the units and the pixels to, the same situation you noted occurs. It is quite aggravating and leads to a lot of redos of things.

I am looking for the best settings to prevent this. Or is this an ArchiCad problem that will be there no matter what the settings are.
Tom Krowka Architect
Windows 11, AC Version 26
Thomas@wkarchwk.com
www.walshkrowka.com
Anonymous
Not applicable
Tom wrote:
have encountered numerous instances where I was placing an element and I saw the dark check-mark cursor when I clicked, but upon closer inspection, it didn't grab the hotspot and my placed element was wrong. I've become so paranoid about this that I am now in the habit of zooming way in on hotspot areas for every click -- certainly a waste of time, but less of a waste that accidentally drawing something wrong. By the way, my cursor snap range is set to 3.
That's what I'm talkin about. The checkmark really does not mean you are on that point. Wouldn't it be better to set your cursor snap range to 1. In my mind, that would give you the most accuracy. But no matter what I set the accuracy of the units and the pixels to, the same situation you noted occurs. It is quite aggravating and leads to a lot of redos of things.

I am looking for the best settings to prevent this. Or is this an ArchiCad problem that will be there no matter what the settings are.
I find the default setting of three pixel snap range to be ideal (especially on a high res monitor). In all the work I have done, much of it very highly detailed, I have rarely had a problem with too many snaps too close together. I do occasionally have to zoom in to particularly complex areas, but these layers are usually turned off in smaller scale views and I am already working close in on the enlarged scales.

Very small snap distances (like 1 pixel) can have the problem that a twitchy mouse (or operator) can fall off the snap in the act of clicking, thus missing the node or edge by a small margin.
Anonymous
Not applicable
Matthew wrote:
...I have rarely had a problem with too many snaps too close together.
That's the weird part, this usually happens when there is only one possible snap.
Matthew wrote:
Very small snap distances (like 1 pixel) can have the problem that a twitchy mouse (or operator) can fall off the snap in the act of clicking, thus missing the node or edge by a small margin.
I thought of that, but my mouse setting is the least balistic of anybody's in the office. I also thought the 3-pixel snap range would help, but it doesn't seem to make much difference.
Anonymous
Not applicable
Jay,

I have found over the years that Windows is a bit less smooth in the GUI department. Clicks don't always register immediately, lines don't always display as cleanly, etc. It also seems to be a bit hardware dependent. I have found Kenington & IBM mice to work better than Logitech and IBM and Apple (they are Windows compatible) keyboards have always worked best for me (yes the old keyboard thing again ). But even with my favorite equipment I have found that I have to be just a bit more deliberate with my clicks in Windows.

Curiously Mac OS9 was better than OSX 10.1 (which behaved about like Win2K) but it has since improved and I am noticing no problems at all in Panther (10.3). Not that this helps you any.

If you are finding that, despite carefully doing everything right, the snaps are still not working reliably, perhaps it is a display card problem. Is this a consistent problem around the office or just one (or a few) machines?
Anonymous
Not applicable
It seems to be spread around. I've talked to most of the users about this problem and they have all experienced it at one time or another.
Anonymous
Not applicable
Jay wrote:
It seems to be spread around. I've talked to most of the users about this problem and they have all experienced it at one time or another.
Hmm, troubling. Seems like it is difficult to isolate. Are you all using pretty much the same equipment?
Tom Krowka
Enthusiast
Our problem seems to be mostly with the roof. We even draw guidelines, with good drafting technique, then put the roof to the intersections with checkmarks and other cursor points. But when the drawing is zoomed, the roof points are not on the guideline intersections.

We are using a logitech keyboard and mouse. Maybe I'll try a switch. But how would those pieces of hardware screw up Archicad. Seems strange.

How could I tell if I had a video card problem? Just change it out and see if it makes a difference? All other programs on the machine work fine, including Autocad. Snapping to points works fine on that program.
Tom Krowka Architect
Windows 11, AC Version 26
Thomas@wkarchwk.com
www.walshkrowka.com
Anonymous
Not applicable
Matthew wrote:
Are you all using pretty much the same equipment?
The boxes are all Dell Precision 360s, but the RAM size, HD size, etc., vary slightly. There are at least two different video cards that I know of, but I'm not sure which machines they are in.
Anonymous
Not applicable
Tom wrote:
We are using a logitech keyboard and mouse. Maybe I'll try a switch. But how would those pieces of hardware screw up Archicad. Seems strange.
ArchiCAD depends on precise feedback from the screen as to which pixel the mouse is pointing at when you click. Remember that making this whole GUI thing work properly is, as the programmers say, not trivial.

I have found Windows to be a bit less reliable and consistent in this regard than the Mac. It is probably because of the wide range in quality, products & manufacturers that Microsoft has to accommodate and that Apple has been doing it longer.

To be fair I have seen some troublesome video driver problems with AC & PM on the Mac. They were always display anomalies though, like trails of selection dots left all over the screen in PlotMaker on a blue G3 tower. Mouse response on the Mac has been generally excellent except (in my experience) with cordless Logitech mice and OSX 10.1 which was still a bit rough around the edges.