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Grid unusable at some zoomlevels

Posted: Sat Jul 28, 2012 12:01 pm
by LeoP
With the grid set on 'Auto', it takes thirteen (!) steps of zoom (either in or out) for the dots to change, while at the eighth step the grid already lost its usefullness.
Can this not be parameterized?
Like specifying the number of zoom steps it takes for the grid to change?
Or a minimum and maximum number of pixels between grid dots?
Or introducing a 1-2-5 sequence to 'bridge the gap'?

I noticed the same kind of behaviour in QCAD 2.2, but iirc that was not as bad as this...

Re: Grid unusable at some zoomlevels

Posted: Sat Jul 28, 2012 12:33 pm
by andrew
LeoP wrote:Or a minimum and maximum number of pixels between grid dots?
Spot on :)
Edit - Application Preferences - Graphics View - Minimal Grid Spacing (px)

Re: Grid unusable at some zoomlevels

Posted: Sat Jul 28, 2012 3:01 pm
by LeoP
andrew wrote: Spot on :)
Edit - Application Preferences - Graphics View - Minimal Grid Spacing (px)
Hmmm...
I've been playing around with these settings but cannot see any difference between 5, 1, or even 50 pixels; not even after restarting the program.
And it still takes 13 clicks to change them.
I may be doing something wrong here (Windoze XP-SP3) but cannot figure out what.

Re: Grid unusable at some zoomlevels

Posted: Sat Jul 28, 2012 9:24 pm
by Clive
Hi Leo
I`ve tested this and agree, bug report added:
http://www.ribbonsoft.com/bugtracker/in ... ask_id=655

Re: Grid unusable at some zoomlevels

Posted: Sat Jun 29, 2013 7:55 pm
by LeoP
Just experimented a lot in v3.1.2 under windows and found these two things about the grid:
  • changing the minimal grid spacing requires a program restart to become effective, there is no mention of this.
  • the number of wheel clicks required for the gridspacing to change is still 13, the grid is still unusable close to the change.
    At small settings of minimal grid spacing the first few steps after the change (zooming in) are unusable because of the grid density, at larger settings the problem shifts towards the steps just before the change because of the very large distance between the grid dots.
Addition of a maximal grid spacing in the preferences would make the grid usable at any zoom level.

:? Is this a feature request or a bug report?

If it is deemed a bug, http://www.ribbonsoft.com/bugtracker/in ... ask_id=655 should be re-opened...

Re: Grid unusable at some zoomlevels

Posted: Sat Jun 29, 2013 8:18 pm
by andrew
I don't think a maximum grid spacing would make any sense. Forcing the grid spacing to be between any two given value would mean to have a grid with an arbitrary spacing (e.g. 7.45667 units instead of 10 units).

QCAD adjusts the grid as follows:
- starting point is a very low value or the value indicated by the user in the grid preferences. For example 0.001
- If a grid with spacing 0.001 would be too dense (i.e. 0.001 units < min grid spacing in pixels), scale up the grid by factor 10. Repeat until spacing is >= min grid spacing in pixels.

Re: Grid unusable at some zoomlevels

Posted: Sat Jun 29, 2013 8:41 pm
by LeoP
My problem is not the highest density, but rather the lowest: the dots are too far apart to be useful...
scale up the grid by factor 10
This factor could be replaced by a 1-2-5 sequence as used in electronic measurement equipment like scopes (why would they use that :twisted:).

Forcing the grid spacing between two given values would not necessarily lead to awkward grids, just interpret it as a the description says: as a maximum.
Below that maxmimum you can follow any rule to widen the grid, if the widening according to the rule exceeds the maximum, proceed with the given minimum.
It would lead to a variable number of dots per drawing unit, but that could be helped by adhering to a 1-2-5 sequence..
And this works in both directions, too.

I noticed the ruler display has a more usable approach...

Re: Grid unusable at some zoomlevels

Posted: Sun Jun 30, 2013 11:27 am
by hungerburg
I think I understand as follows: the (minor) grid at some zoom levels is too coarse in your opinion. As a workaround you propose to change the number of subdivisions (of the major/meta grid) at these levels: instead of the fixed number of ten, make them 20 or 50. Minor grid points could then not only fall on, say 100, 200, 300...900 but also on 100, 150, 200, 250...950 or even 100, 120, 140, 160...980. The pixel-distance of grid points while zooming would not make such big jumps, as it does now. Did I get that right?

PS: I found that, when drawing to the grid, I use a lot of zooming, mostly to get at the center of two points, where there is no line, that would give me a handle there anyways. I don't think that a variable number of subdivisions would confuse too much and I'd consider this a worthwile idea, if not, maybe though, I should make myself more aquainted to the command line ;)

Re: Grid unusable at some zoomlevels

Posted: Sun Jun 30, 2013 11:50 am
by LeoP
You hit it, spot on.

Most of my drawing is done in the early development phase, the phase where the drawing itself is a jumble of assembly and part views, cross sections etc; when shapes, sizes and distances are not yet fully defined and often need tweeking by 0.1mm or so (I develop small machinery, largest part sofar is a 'gripper rail' measuring 17mm dia, 84mm long; M3 is a BIG screw to use, M4 is already humongous).
I know, this sort of tweaking is easy enough with the command line (mv @0.1,0 and the like) but I like to drag stuff to see if it really fits there (not to mention use the snap functionality).
Since the shape is not yet fully defined there is no block to move, and selecting objects can be quite tedious with all the zooming back and forth. And in complete accordance with Murphy's Law you tend to forget one or two of them...

Once I get the jumble to look and fit right I start exporting bits and pieces to the individual drawings for the manufacturing of the parts, that's where the final dimensioning takes place.
Only after that I create the correct assembly drawings (that to some extent look just like the jumble I started with :) ) and material lists...