The great divide

[Anonymous]

Hi Folks,

As a very new ArchiCAD 9 user, I'd be grateful for a little assistance.

To try to get up to speed with things, I'm rattling through the Training Guide that came with our version of ArchiCAD 9, which involves drawing the Drucker-Brownstein residence.

Unfortunately, I'm having problem inserting some windows.

As part of the training guide, you are required to insert 4 windows on an equal spacing around the perimeter of an arc. However, selecting the division option does not give the correct result (the wall width at the ends of the wall are far greater than the gaps between the windows).

To try and resolve the problem, I've opened the next file in the sequence of training files where the windows appear in the correct locations; however, when I compare the location of the windows with the snap points, the windows locations do not agree with the snap points.

So, come on then guys, what's going on?

Is it me, or are you all rolling abount on the floor saying "he fell for that old nut shell"

I should also say, that I may be a new ArchiCAD user, but I'm an old, old hand when it comes to AutoCAD (if I'm allowed to mention that name in these parts), and with the exception of this little glitch, I'm seriously impressed so far.

Many thanks

John

[Anonymous]

John_C wrote:
however, when I compare the location of the windows with the snap points, the windows locations do not agree with the snap points.

I am not familiar with the tutorial project but the difference may be in which side of the wall you are snapping to, how the reference lines are set up, or differences in the snap points settings.

Without knowing the specifics, I can only suggest you check all these possibilities (wall reference lines could also affect things) and by the time you figure it out you will have learned a lot about haw ArchiCAD work.

I'm glad to hear you're enjoying the change so far. It will get even better as you go along.

[Anonymous]

John,
Does the training guide tell you that you can get the center
points of the four windows by setting the divisions to a certain value ?
As you know, the true center points for four equally spaced windows
are equidistant from each other but are different from the points
generated by dividing the length of the wall into equal spaces.
So I can't see how the division method could possibly work.

I believe you need to do it the old fashioned way by adding the widths
of your windows, subtract that from the length of the wall, divide this
number by the number of pieces of blank wall, then you have the
segment lengths between the windows. Add one half of the width of a window
to one segment length and this will be the length from the end of the wall
to the center of the first window and again use this same length to the center
of the next window.

In the case of curved walls, all of these lengths are arc lengths derived from
the arc length of the curved wall and the arc lengths of the widths of the windows.
You can get the arc length of the wall in the element information floating pallet
The formula for arc length is the following.
Arc length=PI times the Radius times the Angle divided by 180.
Where "Radius" is the wall radius and "Angle" is the included angle of the arc segment.
Using this formula you can get the center points for the windows using
the method described above but in arc lengths rather than straight lengths.
Using distances rather than divisions you are able to get these points to display
as distances measured on curved walls are arc lengths rather than chord lengths.

I may be completely wrong here, so please someone show us both
how this can be done using divisions, exempting some trivial case, of course.
Peter Devlin

[Dennis Lee]

For what it's worth, I had the exact same question at that stage of the tutorials not too long ago. I think what I did was just play with the division so that I divide the snap points to 8 or 9 along the arc, and put the windows in every other snap point, which got me close to what I would be satisfied with if I was the architect for the project.

[Anonymous]

Cheers for the replies folks.

From reading what you say, it sounds like the training guide is misleading, and whilst that might not surprise me, it does concern me as it doesn't show the product in a particularly good light.

With a training guide designed for new users, things really should work the way book the tells it.

As you say Peter, to achieve a balanced look, it is not as simple as dividing the length by 5 and adding 4 windows at the snap points. If the snap points were truly at the 1/5th points, then the gap between the extreme windows and the end of the wall would be half as wide as the gaps between adjacent windows. However, when I try to follow the guide, the gap at the end of the wall is more than double the gap between adjacent windows which is why I was scratching my head.

I might try using 20% as the snap distance, and see if that makes any difference (I know it should be exactly the same, but lets wait and see).

If anybody has any other bright ideas, I'd be happy to hear them.

[Anonymous]

John,
When you say " If the snap points were truly at the 1/5th points",
does this mean that when you set divisions to five that the
snap points are not at the 1/5 points ?
Are they not equal, or are they equal but not dividing the wall into
five intervals but some other interval ?

Does AutoCAD have some automatic means of distributing windows
in a wall with equal spaces between them ?

The reason I ask is I am wondering how you accomplished
this task before you started using Archicad.

Peter Devlin

[Anonymous]

Peter wrote:
I may be completely wrong here, so please someone show us both how this can be done using divisions, exempting some trivial case, of course.

It can't typically be done with divisions unless the width of the window is a whole number divisor of the wall length. Not trivial but rare (except perhaps for Richard Meier). It can easily be done with the multiply/distribute command.

[Anonymous]

Hello Matthew,
It occured to me to try the multiply/distribute command to
array hotspots or windows along the edge of a curved wall,
but it doesn't work.
Meaning, it does not put the hotspots in the right place
for the present purpose.
Could you explain how this is done.
Thank you,
Peter Devlin

[Anonymous]

Peter wrote:
... are they not equal, or are they equal ...

The with of the wall sections between the windows appears to be equal, but the start and end interval are far larger than I would expect to see.

As Dennis said earlier, it is possible to archive a similar effect to the desired one by setting the divide snap to 9, and using alternate snaps, however, this isn't what the guide suggests.

I think for now I'll assume that it's me being overly pedantic (just for a change 😉 ), and that the guide's at fault for being a little vague and woolly.

If you were using AutoCAD, there would be many ways of skinning this particular cat. The DIVIDE command inserts the required number of POINTS at the desired interval, or you could use the polar array command to position the objects around the curve segment.

That said, you still need to take Matthew's comments into consideration if you want to do the job propperly.

Many thanks.

Ps Have I mentioned that I can be pedantic from time to time

[Anonymous]

this thread struck me as interesting so I looked through the reference guide and found what I think may work for you.

I find if you draw a line in the center of your wall and then set your snap points to divisions of 4 in your case

then set the special snap points to be "between intersecting points"

This should put your nodes in the desired place along one side of the wall. Then you can repeat for the other. I hope this helps you.