Friday, July 30, 2010

Creating a Quick Trellis in Revit using a Curtain Wall

1. Start with a rough idea of how big the trellis will be and a rough idea of what the major support structure for the trellis. This might be using parts that are already built in your model or you might need to put in some columns, beams, etc.

2. Start sketching the outer boundary of the trellis with a Roof
Home > Roof > Roof by Footprint

3. Go to the Properties of the Roof and switch the Family to System Family: Sloped Glazing (this is a Curtain Wall used for skylights) and then create a new Type (name it something easy to distinguish from other skylights that might be in the project)

4. Go to the Type Properties

There are lots of setting here that we can tweak to get Revit to automatically generate a simple trellis.

Set Curtain Panel > Empty System Panel:Empty (this gets rid of the glass)

5. Grid 1 and Grid 2 are set to be perpendicular to each other by default. We will use one of them to create the smallest layer of the trellis and the other to create intermediate size beams.

In this case Grid 2 is going to be the intermediate layer.

Under Grid 2 Mullion select the profile that you want for the beams (I picked a 2.5"x5" Rectangular shape)

Under Grid 2 Pattern you can adjust the layout and spacing that Revit will use to generate the curtain grid

Now hit Ok to see what you created. If these beams are not running in the direction that you want you can switch this over to Grid 1.

6. Go back into the Type Properties to add the smaller layer to Grid 1 like we did for Grid 2. I chose a smaller profile and closer spacing Grid 1.

I also changed the Join Condition to Border and Grid 2 Continuous. This means that the parts of Grid 2 will not be interrupted by the Grid 1 and give the appearance of continuous beams.

Take another look to see the effects of the setting you changed.

7. This trellis is great for early on in the design process since you can easily change the shape of the roof sketch. But there are a few things wrong with it if you take a closer look. like the fact that the smaller trellis pieces are in the middle of intermediate ones instead of being on top.

8. One thing that is wrong is that the intermediate members stop short. Adjusting the Mullion Joins can fix this.

9. The other thing that is wrong is that the smaller trellis pieces are in the middle of intermediate ones instead of being on top. There are a couple ways to fix this. An easy way is to create a copy of the Curtain System above the original. Duplicate the original Type and name it something that makes it easy to tell them apart. Naming them something like Trellis-Upper Layer and Trellis-Lower Layer might be appropriate. In the Trellis-Upper Layer just turn off the grid pattern and mullion profiles for the lower grid. And do the opposite settings in Trellis-Lower Layer.

Thursday, July 8, 2010

Creating Patterns

If you need a simple, repeating pattern, this can be done with some trial and error by writing a .pat file. The one that comes preloaded with Revit has some instruction on how to do this. You should be able to find it here:

C:\Program Files\Autodesk Revit Architecture 2010\Data\revit.pat

I think Steve B., Joel, Adam, and I have all messed with this, so ask one of us if you need help.

As the pattern you need becomes more complex, it takes more time to figure out how all of the coordinates to draw all of the lines using the previous method. I found an AutoCAD Lisp routine that may help out.

1. Open AutoCAD

2. Go to Tool > Load Application

3. Load the routine from K:\LISP\HatchMaker.lsp

4. In a blank cad file type drawhatch in the command line and say Ok to the popup

The routine will adjust the settings and draw a box to setup for the pattern.

5. Draw your pattern within the box using individual line segments (no polylines). The endpoints of your lines must snap to the grid (which the routine already setup). To navigate around it may be easier to turn the SNAP off, just be sure to turn it back on when you draw lines.

6. When you are finished drawing type savehatch in the command line
A dialog box will open reminding you about the snapping; hit enter.
Then you select off of the lines you drew and hit enter again.

Enter in a name for the pattern. Then for some reason a dialog box will popup again asking for a name so just enter in the same one and browse to where you want to save the pattern.

You should then be able to load you pattern just like any other drafting pattern. You can manually change the pattern file to a drafting pattern as described in the revit.pat file. The pattern generated doesn't really have a units, so you will have to adjust the scale when you import in into Revit. Scaling will not always work because of the limit on line sizes in Revit.