Fill pattern with circles?

[bregnier]

I'm trying to use a hatch pattern to represent a circular frit on some glazing. The pattern is diagonal, similar to a staggered hole perforated metal. It's not necessary that we get the dimensions 100% correct as it's for representation in elevations and 3d views.

I can't for the life of me get any pattern to show up properly. It either goes crazy on import or shows up fine in the fill pattern preview but is just a solid gray when inserted into the model. This might be due to the fact that .pat files don't do curves, so there are a lot of teeny little lines in the pattern, which is tricking revit into thinking that the pattern is so closely spaced it should show it as gray.

Anybody come up with a solution to this problem?

[d.stairmand]

Circles are the most difficult thing to do in Hatch Patterns, and tend to go out of control the more distant you are from the Origin.
Try using a square - Or just a Model Line on the Glass

[hugh.69031]

Revit drops fine detail. There seems to be a minimum line length of 1/32" and other constraints that cause problems for patterns containing short segments. You may find a coarser representation is sufficient. Acad's DOTS, DASH, CROSS, TRIANG or HEX patterns all have a staggered arrangement and HEX is pretty close to a circle (if you stand well back) but it may need tweaking to get the right effect.

What is the frit's diameter and spacing?


Hugh Adamson
www.hatchkit.com.au (http://www.hatchkit.com.au)

[bregnier]

I was going to start off with something like 1" circles with about a 1.25-1.5" spacing, but we're still figuring all of that out. This was really a place holder, but I was trying to get it as close as possible to something we might actually do.

[jsnyder.68308]

I used a program called HatchKit to make a fill pattern with 4" diameter "circles". It actually used many short line segments to make tessellated curves that looked pretty good - I'm not sure how circles as small as you are looking for would turn out.
Hatchkit can take an AutoCAD drawing and turn it into a fill pattern - pretty slick. It might be worth the money (it's not free) if you are spending more than a couple of hours messing around with this problem.

[hugh.69031]

Attached is a rescaled AutoCAD HEX2.5 having 3 defining lines and a FRIT based on circles which has rather more. I would be most interested to learn which is preferable in practice given there must be a tradeoff between rendition speed and accuracy.

Hope this may be of use.

Hugh Adamson
www.hatchkit.com.au (http://www.hatchkit.com.au)

[bregnier]

First of all, thank you so much for your help. This is fantastic.

Revit, for whatever reason, appears to be unable to handle hatches with very short line segments, like the circle hatch. I'm having a similar issue with this pattern that I had with previous attempts - it appears as a solid fill most of the time. If I switch to 12" = 1'-0" scale and zoom way in it will appear, otherwise I get solid black.

The hex pattern, however, looks and works great. This is probably the best workaround for the time being.

[Dimitri Harvalias]

I probably wouldn't show a pattern at all. I'd simply go with a light grey solid fill as surface pattern. You suggested that it is for representational purposes only and the amount of 'thought' required to redraw 1" circles on large expanses of glazed area is not worth it in my opinion. For an overall building elevation, even at 1/4" = 1' a 1" circle is going to be muddied by the number of lines required.
Just my $.02

[hugh.69031]

HEX is particularly efficient because it interweaves just 3 pattern elements to portray hexagons at a fixed spacing but it can only be scaled - you cannot vary the hexagon spacing without varying the hexagon size.

Attached is a FRIT8 pattern based on an octagon circumscribing a 1" circle staggered at 2" centers. I would be most interested to learn how well it performs compared with HEX2.5 in practice. This pattern can be changed to vary element spacing.

We also benefit immensely by learning where detail becomes too small to model practically within Revit. It's apparent that the earlier FRIT pattern fell below that threshold.


Hugh Adamson
www.hatchkit.com.au (http://www.hatchkit.com.au)