greenfin wrote:
while on the subject of roofs, i would just like to confirm if:

1. you can't trim a roof to another roof?

2. you can only trim walls that actually intersect a roof? e.g. a wall 3m high cannot be trimmed to a roof whose base is at 4m?

3. if yes to 2, you have to raise the height of the wall so it intersects the highest part of the roof before you can trim it?

4. you can't pick which roof to trim your walls to?

5. after trimming a wall to a roof, you make changes in the roof's height/slope/configuration, you have to re-trim the wall to the 'new' roof?

6. in revit, you can 'attach' your walls to a roof so that the walls' configuration (height, shape) automatically adjusts to any changes later made to the roof. can you do something similar in archicad?

TomWaltz wrote:
1) yes, you can
2) why would a 4 meter high roof trim a 3 meter high wall? If you want to extend the wall, yes, you can.

why indeed? sorry, revit-speak. there's only one command for trim/extend in revit and it only says trim on the icon, thus my use of the word 'trim' to mean both trim and extend.

TomWaltz wrote:

Most of these are in the Archicad user manual.

i've read the section on roofs before posing my questions. some things are not covered in manuals/guides and even when they are they are not always clearcut and some problems can't simply be foreseen. that's why these forums exist, right?

TomWaltz wrote:
5) it depends on which trim command you use. If you use "Trim to Roof" (which allows all of the above to work), then no. If you use Solid Element Operations (which does not allow all of the above to work) then yes.

all my questions were actually about the 'trim to roof' command. i got too involved with it, i ignored other options.

David wrote:
Make sure to Suspend Groups, Polyroofs are grouped by default.

thanks. the group was suspended when i worked on the polyroof. i understand that 'alt + G' is a temporary suspend command so shouldn't the polyroof automatically revert back to its original grouping?

how do you edit a wall profile? i'd like to do a customized wall trim (see attached) for the front facade. from what i gathered you do this in archicad by creating a roof structure to trim your wall to, is this correct? can you work on a wall's profile in elevation/section? i tried this but, unless there's a special command out there that i do not know of, this doesn't seem to be possible.

to do this in revit you first create a regular wall then 'edit profile' it in the right elevation/section. the view will then switch to 'sketch' mode (see attached, right) so that you can draw or edit your profile in 2D. when done simply click 'finish sketch' and you have your wall trim.

I learned a lot of things about ArchiCAD while trying to solve the problem of the facade trim. Most of them what you can NOT do and the rest how to go about it in the most roundabout way.

You cannot:

1. edit a wall's profile (or any profile for that matter) in elevation/section.

As a Revit user this is the most logical way to edit the profile of a wall.

2. edit an object's shape graphically but you can change its parameters.

If for some reason an object is not directly editable in the project views, the next option in Revit would be to edit it using 'edit family' which is like ArchiCAD's Profile Manager only you can edit in any view (plan, elev, section, 3D) as well as change or add new parameters.

3. create a roof with a vertical surface; you can create the most complex shapes as long as none of the parts are vertical.

I've never used a vertical roof before but I quickly checked and Revit allows it in complex roofs created by extrusion in elevation/section.

Roundabout way to edit a wall profile:

1. Custom Profile: Do as Dwight suggested.

Dwight wrote:
In cases like these, the Custom Profile should be a wall placed perpendicular to the building wall at the depth you need to express the new element, defining your quoin stack, for instance. Or your brick arch.

To edit a custom profile, sketch over the elevation with a fill to redefine the custom profile, pasting the new fill into the custom profile window or edit the defining fill right in the custom profile window.

Yes, relative to Revit, there's an extra initial step, but each custom profile is saved, so there's payback for repeating situations.

2. Empty Opening: Create the wall and add several empty openings until you get the right profile.

3. Solid Element Operations: Create the wall and some solid element/s (e.g. about 13 stacked slabs of varying widths) that will approximate the configuration of the profile you want to achieve to act as 'operators'.

4. Trim to Roof: Create flat roofs (about 8 in my case) at varying heights and positions and trim wall base to roof.

5. Custom Component Using Slabs: It seems you can create complex shapes using slabs and save them as custom door/window components. I tried this but I don't know where my door ended up after I saved it so I haven't been able to use it but I'm afraid that it's not going to work.

ArchiCAD wrote:
Using ArchiCAD Construction Elements (such as Slabs), create the Door Panel on the Floor Plan. In case of Door/Window custom panels, what you draw in the X-Y plane of the Floor Plan Window will be ‘stood upright’ in the Window/Door library part (rotated 90 degrees around the X axis – as described in the GDL Reference Guide). For other custom component types, this condition does not apply.

6. Import blocks from DXF/DWG: I could draw the profile in AutoCAD and import it into ArchiCAD but I'm not sure if it could adopt the attributes of a wall. I'm not going there as I'm allergic to AutoCAD. I haven't even installed it even though it came with Revit.

Richard wrote:

greenfin wrote:
I learned a lot of things about ArchiCAD while trying to solve the problem of the facade trim. Most of them what you can NOT do and the rest how to go about it in the most roundabout way.

You cannot:

1. edit a wall's profile (or any profile for that matter) in elevation/section.

This is certainly news to me! Especially since I've been doing it for quite awhile in the section editing window of complex profiles. And you even get the option of making the profile "stretchable" in the limits of your choosing. However, with the "merge" option, you don't even need to go into the profile editing window.

By 'section' I figure you mean 'cross section' and do it the way Dwight suggested I suppose? This does not apply to my problem. By 'section' I meant the section view in case of interior walls. For both elevation and section I was referring to the surface, right/left, in/out.

Richard wrote:
I'd really suggest you fully learn to use the program before making pronouncements such as the above.

Thank you. Suggestion taken. But how do you 'fully learn the program unless you use it? I was not making 'pronouncements' rather stating some observations based on my experience with it. I have consulted the manuals, read the help files, considered everything possible as listed in my previous post.

If I had the answers I wouldn't be asking for help here. Please take a look at the the facade I'm working on (attached two posts before) and tell me how I should go about doing that in ArchiCAD. I would really like to know the simplest and most direct way of doing it.

greenfin wrote:
If I had the answers I wouldn't be asking for help here. Please take a look at the the facade I'm working on (attached two posts before) and tell me how I should go about doing that in ArchiCAD. I would really like to know the simplest and most direct way of doing it.

Having worked with both programs I understand your frustration. While both programs do much the same thing (make building models) they go about it in rather different ways.

ArchiCAD has many useful and sophisticated tools which Revit lacks, but they have accumulated over a long development process that has seen computers go from 16MHz & 8MB RAM (when I started) to around 3GHz & 3.5GB (WinXP) to upwards of 8GB (MacOS & Vista 64) now. As such they are quite varied in their behaviors and capabilities.

Revit on the other hand has relatively few basic functions that can be a bit clumsy at times by comparison to ArchiCAD but have the advantage of being conceptually simple and consistent throughout the program.

The section tool is one of the older functions in ArchiCAD and is in serious need of improvement (ie it is often easier to edit in a 3D section/elevation view than with the section tool). The existence of both Trim to Roof (the old way) and SEOs (the newer function) as ways to fit walls to roofs is another example of this legacy.

If GS were to reorganize the program to have the outward clarity and consistency of Revit while retaining all of its sophisticated capabilities and making them more accessible, I think its advantages would be far more evident to more users.

I wonder sometimes if GS were to just make all the existing features more obvious and accessible (adding no new functions) that this might seem to many to be the biggest upgrade ever.