topic Re: Surface in columns in Revit API Forum

Surface in columns

Anonymous — Mon, 12 Mar 2018 11:22:32 GMT

Hello everybody,

I am checking the surface of two columns. One one of them is a circular section and the other a square column.

The dimensions of the rectangular section is 0.475x0.61x4, which means a surface of 9.2595. However the area parameter gives 4.63, exactly the half.

In the case of circular section, has a radio of 0.30 and a length of 4.0, so its area is 3.911. But its ara parameter has a value of 1.956, it is half again.

Someone could say me why it happens. I reckon the area parameter is the surface of column, am I wrong?, it is other area?.

Thanks,

Javi

Re: Surface in columns

Anonymous — Mon, 12 Mar 2018 12:40:34 GMT

Have you checked if the units are correct? By default, Revit API gives you the result in inches, for example.

Try to add this to your code:

Area = UnitUtils.ConvertFromInternalUnits(area.AsDouble(), DisplayUnitType.DUT_SQUARE_METERS);

where area is your parameter.

Cheers

Ruben

Re: Surface in columns

RPTHOMAS108 — Mon, 12 Mar 2018 17:22:46 GMT

As far as I can tell surface area isn't a built in parameter of a structural column family.

If you are talking about parameters associated with the section shape then these are filled in by the family author. If you are talking about another parameter (based on formulas) then the family author created those and Revit makes no judgement about their accuracy. You can edit family to see what is perhaps being done wrong.

Unless you can indicate the built in parameter these are associated with?

Re: Surface in columns

Anonymous — Thu, 15 Mar 2018 08:23:27 GMT

I checked , is not a problem of units. But thanks for your answer

Javi

Re: Surface in columns

Anonymous — Thu, 15 Mar 2018 08:25:13 GMT

I will check the BuilInParameter. Thank for your answer

Javi

Re: Surface in columns

Anonymous — Thu, 15 Mar 2018 08:30:10 GMT

I've checked that myself and I think i know what you mean.

This post can clarify a bit: https://forums.autodesk.com/t5/revit-api-forum/door-and-window-area/m-p/7853331#M29493

I've tried now and the Area of a column is the total area of the solid:

(i.e. [B+H] x 2 x height + BxHx2) / 2

(area of the lateral + area of top/bottom of column ) / 2

e.g. a column have B=0.5 m, H=1m and height of 4m. The area will be 6.5m2

The same thing is for beams.

Basically, the are that Revit shows is the area of the total surface of the column divided by 2. Why is that? I don't know...

So, if you want to obtain the true section area you have to first obtain the B, then the H and then multiply (square column). For the circular, you just need the pi x R^2

Cheers

Ruben

Re: Surface in columns

RPTHOMAS108 — Thu, 15 Mar 2018 21:14:18 GMT

If you are speaking of the parameter below then I don't think it holds true that it is always half the actual surface area. I have this column that magically takes up no space at all (I section perhaps).

This parameter is not something inherently useful to the structural framing/columns categories concerned it would seem. I think we need to see if such things are visible in the UI as that helps certify their fitness for purpose in terms of being information for end user.