topic Re: Model complex triangulated surfaces in Modeling

Model complex triangulated surfaces

Anonymous — Tue, 23 May 2023 14:37:02 GMT

I am trying to model this object in ArchiCAD.

I have already done it in Sketchup and have exported it as a DXF to create an AC object out of it. The result of this process can be seen on the image attached.

Now, I need to add thickness to these triangular surfaces so I can add doors and have a good 2D representation.

What tool should I use? Slanted walls, roofs, shells?
Any idea how this should be done?

Thank you for your help and time.

Re: Model complex triangulated surfaces

Erika Epstein — Wed, 21 Mar 2012 19:59:53 GMT

model it in archicad using its tools so walls are walls and you can place doors and window...there is a wall type for a sloped wall which should help you.

Re: Model complex triangulated surfaces

Anonymous — Thu, 22 Mar 2012 08:56:24 GMT

Yes indeed, it all sounds very logical but isn't that easy in practice.

How should I model those triangles that only have one point touching the ground? Roofs and SEO to cut the two adjacent slanted walls? This is super hard to do.

What makes it harder still is that the object imported in archicad doesn't have hotspots at its nods but only at the corners of an invisible bounding box. Maybe if I could import the object from Sketchup with different option (what options?) it would work. (I'm working on mac so no SK/AC translator available).

Thank you for your fast response.

Re: Model complex triangulated surfaces

TMA_80 — Thu, 22 Mar 2012 13:32:00 GMT

Perhaps this topic could give some answers :
http://archicad-talk.graphisoft.com/viewtopic.php?t=34317&postdays=0&postorder=asc&&start=30

You may also try the ruled shell and see if it is of any help...

Re: Model complex triangulated surfaces

Anonymous — Mon, 02 Apr 2012 10:43:51 GMT

The article is interesting as they go trough several methods but it also seems as though the model was not doe properly in the end.

Is it possible to import from Sketchup 3D models with hot spots at each node?

Re: Model complex triangulated surfaces

Anonymous — Tue, 03 Apr 2012 01:33:29 GMT

You can get hotspots in plan by exploding the symbol. Getting them in 3D is a bit trickier. IFC usually does the trick but I don't know any easy way to convert SKP to IFC.

If the GDL is not too complex it's possible to manually write in the nodes from the auto-generated 3D script but this is fairly advanced stuff.

It might be easiest just to remodel from scratch using the shell tool. If you don't already have the coordinates for the points you can dimension them in SketchUp if you have the pro version (which technically you should since you are using it for professional purposes).

Re: Model complex triangulated surfaces

Anonymous — Tue, 03 Apr 2012 08:29:16 GMT

I do have a pro version of sketchup so getting the coordinates of the original model is not a problem. However, getting involved up to my knees in IFC data and GDL programming sounds a bit much. I also think it would be better to use this brilliant new shell tool.

After going threw some tutorials and fiddling with it, I'm not able to generate flat triangular surfaces.

This is easily achieved with meshes but doesn't allow composite structures.

What options am I missing in the shell tool?

Re: Model complex triangulated surfaces

Barry Kelly — Tue, 03 Apr 2012 08:50:12 GMT

Benjaminmeyer wrote:
What options am I missing in the shell tool?

I think you would have a hard time making this from the shell tool.
They are only good for a single profile extruded along a straight or rotated path or two profiles blended together along a straight path.

You would have to construct each surface as a flat shell and rotate and trim each one.

You will be better off using sloping walls tromed with Solid Element Operations (or trommed to a roof for a fixed result) or individula roofs for each surface.

Barry.

Re: Model complex triangulated surfaces

NCornia — Tue, 03 Apr 2012 23:08:18 GMT

For the conceptual and 3D creation the shell tool is probably the best tool IMHO since you can draw the planes visually in 3D very quickly.
Easy to draw triangular surfaces (see next paragraph). BUT for the documentation phase I have to agree with Barry about using sloped
walls since shells will not clean up nicely with each other like walls do.

For fun though, here is how I would use the shell tool to make this conceptual model: In the image below I used a slab at zero and an elevated
slab as reference planes then I drew rectangular shells. No rotate or trim necessary. Next, using the move node option in the pet palette I
made each surface triangular by dragging one node on top of another on one of the sides. Of course without more than one view I am sure
I did a bang up job of replicating the model exactly as you have it.

To model it correctly you need the x,y,z points of each vertex. And for this to work well with the shell tool you would want to create the horizontal
planes that represent what would be the structure's roof and floor slabs. You would use the roof tool (single plane)* in the case the planes are
inclined or slab tool if they are not inclined. From these planes you can draw the shell contours in 3D.

Onto the doors and windows, you would have to use a skylight object in the case of a shell if you wanted to have an object that is actually hosted
and cuts through the shell. Or you could cut a hole in the shell where the doors and windows should go and either use the Curtain Wall tool (recommended)
OR place a wall that is as wide and tall as the door/window and place a standard door/window there.

*Side Note: The roof tool (single plane) is a good choice to use as a design tool for odd planes in 3D views as well since you define your roof plane
by defining 3 points in space. http://www.graphisoft.com/ftp/publishing/ac15_help_INT/Files/wwhelp/wwhimpl/js/html/wwhelp.htm#href=03_Virtual%20Building.06.165.html
So if you know what the coordinates are you can input them into the Tracker. A trick I use is to place columns (any object would work really)
to mark the points graphically so I can snap the roof plane to points in 3D. I first place a small circular column in floor plan and then stretch its height
in 3D to the appropriate z-height. I then have "tent poles" to references to draw a roof plane in 3D.

Best regards,

Re: Model complex triangulated surfaces

Anonymous — Wed, 04 Apr 2012 07:51:09 GMT

Wow, I'm very impressed.

Since I need good documentation, I will try the wall and roofs snapped to columns and will get back to you if I get into trouble.

Thank you,
Benjamin

Re: Model complex triangulated surfaces

Anonymous — Wed, 04 Apr 2012 10:49:37 GMT

This method seems good but I'm having trouble with connections:

On the attached picture, brown triangles are slanted walls and red triangles are roofs.

The line of intersection between 1 and 2 is where it's supposed to be but I can't get rid of the upper part of the wall. It should be cut off by the roof. SEO doesn't work in this case and the "connect to roof" doesn't either.

Intersection between 2 and 3 is fine.

Intersection between 3 and 4 does not work because walls 2 and 4 are connecting, resulting in an undesired intersection line. Roof 3 should trim wall 4.

Any ideas on this one?

Re: Model complex triangulated surfaces

NCornia — Wed, 04 Apr 2012 11:28:03 GMT

I would recommend having an SEO layer that is hidden in the end but on this layer you would have roof planes or other objects that cut the walls as desired. Sometimes it is much easier to perform SEO with operators that are not involved in the actual structure itself. This will look messy when everything is shown, but after you turn the layer off everything will look clean if done properly. Wall 2 &4: Create a new layer for Wall 4 and change the layer intersection number so that it will not interact with Wall 2.

HTH

Re: Model complex triangulated surfaces

David Maudlin — Thu, 05 Apr 2012 12:23:50 GMT

NCornia wrote:
I would recommend having an SEO layer that is hidden in the end but on this layer you would have roof planes or other objects that cut the walls as desired. Sometimes it is much easier to perform SEO with operators that are not involved in the actual structure itself. This will look messy when everything is shown, but after you turn the layer off everything will look clean if done properly.

This layer can be set to Wireframe mode in the Layers dialog box, so the elements on it are Wireframe in the 3D Window, and the finished model is easier to see.

David