Draw 3D point through Code in ArchiCAD?

[cad developer]

Hi Graphisoft Community!
I am looking for a straight forward way to draw/place (create and display) a 3D point in ArchiCAD. I am trying to use Point3D from C:\Program Files\Graphisoft\API Development Kit 27.3001\Support\Modules\Geometry\Vector3D.hpp to create a point, but I see no option to display this point on ArchiCAD.
Any assistance on this topic will be of great help!!!

Thank You,
CAD Developer.

[Ralph Wessel]

Think of Point3D (and for any class/struct in the Geometry folder) as a maths tool for creating geometric bodies, but not directly for visualisation.

The only classes that directly contribute to 2D and 3D visualisation can all be found in the API_Element union, e.g. API_WallType (for walls), API_SlabType (for slabs), API_ObjectType (for objects) etc. and are generally called 'elements'. Archicad is generally not about raw geometry. Elements are at the core of a project - when Archicad renders that content, the raw geometry is generated on demand from the elements.

So if you want a point in the 3D model, you need to create an element that will generate that point for you. The most obvious choice would be a GDL object - the object could have parameters for one or more points that are populated by the add-on, and when placed in the project it renders the point(s) for you.

You cannot directly inject raw geometry into a scene as a Point3D.

[cad developer]

Hi @Ralph Wessel ,

Thank you for your detailed response. I appreciate the clarification on how raw geometry is handled within Archicad.

Could you please provide a clear step-by-step guide on how to create a GDL object using C++ code ( I need to create this object inside my add on)? This will help me understand how to use GDL objects to render points within the project.

Thank you!

[Ralph Wessel · Accepted solution]

You can create the object just using the built-in library part creation tools (File > Libraries and Objects > New Object…)

You could create parameters to store the x/y/z coordinates and a 3D script render them. You can create library parts in the add-on too, but I don't think it will help in this case (but if you're interested, refer to the LibPart_Test example project, specifically Do_CreateLibraryPart).

Either way – once you have an object – the add-on could place instances of this object and fill the relevant parameters with the coordinates. There is similar code for placing a window object in the Element_Test example, specifically Do_CreateWindow.

[cad developer]

Hello @Ralph Wessel , 
Thank you for the response. I am able to create GDL object sphere and I am working on setting position for the object through code. However, I need to change the material of the object so that I can assign colors to the sphere. Can you suggest any documentation or solution so that I can change the material and color of the GDL object?
Eagerly waiting for you response.
Regards.
CAD Developer.

[Ralph Wessel]

GDL supports a wide variety of parameter types, including materials. I suggest adding another parameter to your object for material and populating that in your code in addition to the sphere position.