Saturday, November 15, 2008

aecRoof Object - Part 1

Can this tool be used for anything more than sketching? It's promoted as just a preliminary tool to map out the basic shape but I use it all the time right thru to CD's. Most of the roof's I do are reasonably simple and you may need to convert to slabs for complex situations but don't count out the simple roof object from being able to do the job. You can't cut a hole out for a dormer (update-Option) or chimney (can't remember when I needed to), it can't overlap itself (as in overhang a lower roof) (wrong - see update) tricks and it's edibility is poor (update- WRONG) but I find it can do for a lot of the work I do and I think a lot of the work for Australian roof's.

Here's a couple of articles on the Archidigm site that illustrate some techniques for creating roofs. Check out this great article on the roof object (I think before aecRoofslabs existed) that Odin wrote based on ADT1 (07/99) and another article. Unfortunately Adesk has never felt that an obscure architectural item such as a roof deserved further treatment.

It seems the guiding wisdom is to convert to slabs and I think because of that the roof object has not been fully explored.

If you are doing mostly residential work, then check out VisionRez's roof object (here compared with the ADT roof, and see what a roof tool should be. It will make your life much easier but unfortunately does not doGablets (Gamblets-UK) like I demonstrate below. VisionRez has some downloadable video's that can be helpful in creating roof's. Most though refer directly to it's own (great) roof tool) but there is some mention of the ADT tool. On reviewing VisionRez's superb rendered images I was struck by the fact that there wasn't a single Gablet (Gamblet-UK) roof. It seems the US just don't do it. But here in the west it's a very common feature (out of fashion at the moment but still used). This is easy to create and adjust using the roof object but it's not obvious so I'm going to show you how with the Roof Object in ADT / ACA.

So to the Roof Obect. You just have to treat her gently and you can get some use from her. Together with my eaves object (wall style) seen in my post here, you can have a simply created model ready to produce 'anatomically' correct renderings, aecElevations and aecSections that you won't need to explode or adjust further.

Some points that hamper the Roof Object that do keep it from being a complete tool

  • The roof object is treated as a sketch tool and does not have styles. Adding aecMaterials would be done globally or per object over-ride. (This affects how you go about a project. Get one right and copy it around otherwise you will have to change each one.) Update: In ACA2009 you can now use MatchProperties to copy display overrides from one roof object to another which makes the above 'hamper' no longer much of an issue at all.
  • You cannot add vertices after you have created your roof. If you need to, you will have to re-create from scratch. (Good practise!) WRONG - see my update in Part 5!
  • Tthere are a small number of situations where it goes haywire. (such as a slightly out of square perimeter). Solution - draw accurately!
  • It cannot overlap itself. This affects dutch gable overhangs and roofs that turn on themselves. VisionRez's roof can do this. WRONG! Let me show you how to do it with the ACA roof!
But what CAN it do? Let me pitch it's good points!!
  • Being a complete object it will adjust each plane when you adjust another. I like that. You can add gables, dutch gables & gablets after the fact. Rather than using an edge style to a slab, restricting my gutter & fascia to the same colour, I can use my 'gutter wall style' . This also allows you the flexibility for you gutter path apart from your roof.  Automation is great but it can be painful when it doesn't work for every situation.
Here's a sample of a roof modelled using the roof object which will NOT be replaced by slabs. i.e. This is for the full CD's. As you can see it can do a some complex roof with limitations (update-much less than I thought). Note that the verandah's are 2 seperate roof objects. There are 3 roof objects shown here.

Ok for Part 1. Click here for all roof posts