How to avoid high column of earth when using real RL's in models

[KeesW]

I prefer using real RL's for floor levels (as recommended by Graphisoft) and am modelling a house on a steeply sloping site with ground level about 180m above sea level. External 3D models therefore default with 180m high columns of earth under the ground floor. Just as well I am not building on top of Mt Everest!

I can avoid this by modelling with nominal levels - say ground floor at 5m (to allow for the slope). Archicad examples conveniently model their examples on flat, or nearly flat, sites floating near sea level which entirely avoids this issue. Is there a way to use real RL's on high sites without generating this problem?

[David Shorter]

Oh I should add that I always work to real levels based on the AHD (Australian Height Datum) and use this as my Project Zero and my Zero Story. Story 1 then becomes the bottom story of my building.

This way there can be no errors.

If the site is way above the Sea level then I limit the depth of my sections and elevations to just below the buildings lowest floor and have a similar cut plane in the 3D window to avoid large columns of earth !!!!

[Lingwisyer]

https://community.graphisoft.com/t5/Wishes-forum/Level-Dimension-to-Reference-Level-sea-level/m-p/18...

You can select all Level Dimension Markers, deselect one then select just the text of that single Marker. This will allow you to modify all of them at the same time.

And though you set Sea Level in meters, all references to it display in what ever units your Dimension Settings say

Ling.

[David Shorter]

Yes I know but its a horrible workaround for something which  should be available when placing the Level Dim in the first place.

You still have to place the Dim and then go back and edit.

This is not good workflow and open to error. It also means you can have different levels on plan and to those shown in elevation and section.

 It should be a single setting for all environments.

[KeesW]

Hi David - Good to hear from you on this topic. It it was your advice that prompted me to work in the same way as you - which is now generating my tall earthen column when I generate perspective or axonometric views. I know that I can limit the heights by limiting the depth of sections elevations but I don't think that this is the same as creating a cut plane. Cut planes affect sections and elevations and often need to be adjusted to suit these views for, e.g. internal elevations and split level views. One can't have a separate cut plane for elevations/sections and perspectives - or can one?

It would surely be more convenient if Archicad had a command or setting that would limit the height of the earth column in 3D views without losing the benefits of preserving actual levels and datums in all drawing views?

[KeesW]

Thanks David. I don't have the same Mesh picture as you. No 'Bottom and Top', no 'Mesh Skirt Height (T)'. I try to show a picture of what I have.

[KeesW]

Sorry - I meant 'Thanks Barry'!

[Lingwisyer]

Mesh Skirt Height being the distance down from the Mesh Reference Plane to the bottom of the mesh is the 1000 in your image.

You might be able to put something like -175000 as your value for it to offset it upwards above the Mesh Reference Plane given your terrain difference is less that 12.5m.

Ling.

[Barry Kelly]

I had a look at this again and what I said won't help you in your case.

Because you seem to be modelling your building at 0 (zero) floor level, and are setting your mesh reference line down at sea level (1187440) and then setting the heights of the top points to their true height above sea level (hence the tall mesh), you won't be able to control the skirt height as I suggested.

You can make it deeper (adjust the figure (860 shown here) or drag the base with the pet palette - height option.

But it can only be moved up to the reference line (zero skirt height) - it can't have a negative value to reduce the height of the mesh above the reference plane.

The only way to hide this height is to limit section and elevation heights and to use a cutting plane in 3D as mentioned before.

Otherwise, set the mesh reference line to 0 (zero) but this will lift the entire mesh up higher.

Then you will have to adjust the height of every top node down by 187440 in your case.

This can be done in 3D with the pet palette with 'Z' height option.

Drag each node down and type ... 187440 ENTER.

If you don't have too many nodes this will be fairly easy.

If you have a lot, it will be rather tedious.

Barry.

[Lingwisyer]

"But it can only be moved up to the reference line (zero skirt height) - it can't have a negative value to reduce the height of the mesh above the reference plane."

AC25 thing? As it works fine for me.

Ling.

[Barry Kelly]

Actually you can if you type the figure in the mesh settings (info box).

It seems you can't drag the base in 3D above the reference plane which is what I was trying.

So, @KeesW , if you type a figure like this in your mesh settings, it should look a lot shorter.

Barry.