04 Elements + Models.dib

#!meta

{"kernelInfo":{"defaultKernelName":"csharp","items":[{"aliases":[],"name":"csharp"}]}}

#!csharp

#r "nuget: Hypar.Elements, *-*"

#!markdown

# Elements + Models

We're almost done with the basics of Elements. We've covered points, lines, polylines, polygons, profiles, laminas, extrudes, sweeps, and transforms.

Now, we'll put it all together to create `Element`s and `Model`s, which will be the basis for the Hypar Functions we create and publish on Hypar.

All this time we've been working with _primitives_, rather than true elements. 

When you do `return` in a notebook, we render these primitives so you can see what's going on, but as we'll see later, if you try to output these in a model on Hypar, nothing will happen. To make something visible on Hypar, we need to create real `Element`s, which are flexible, customizable BIM entities, which can have visible geometry and other properties.

When you build a function, you will set a single `Model` as the output of that function, and add many `Element`s to it, with `Model.AddElement`.

#!csharp

var model = new Model();
var width = 10;
var length = 19;
var height = 20;
var footprint = Polygon.Rectangle(width, length);
// Masses can be used for building masses
var mass = new Mass(footprint, height);
model.AddElement(mass);
return model;

#!csharp

// Add some floors
for(int i=0; i<20; i+=3) {
    // Floor elements represent floors
    var floor = new Floor(footprint, 0.1);
    floor.Transform = new Transform(0,0,i);
    model.AddElement(floor);
}
return model;

#!csharp

// Create a column grid
var xBays = 3;
var yBays = 7;
for(int i=0;i<=xBays;i++) {
    for(int j=0;j<=yBays;j++) {
        var columnLocation = new Vector3((i / (double)xBays) * width - width / 2.0, (j / (double)yBays) * length - length / 2.0, 0);
        var columnLine = new Line((0,0,0), (0,0,height));
        var columnProfile = Polygon.Rectangle(0.5,0.5);
        var column = new Column(columnLocation, height, null, columnProfile);
        model.AddElement(column);
    }
}
return model;

#!markdown

These few built-in types have built-in ideas about how they look: they have default `Representation`s, and default `Material`s. 

A `Floor` creates an `Extrude`, and gets a `Concrete` material, and so on. 

Eventually we'll be defining our own element types, but for now we can also create elements with custom representations by using the generic `GeometricElement` class. Let's borrow some code from a previous chapter:

#!csharp

// Construct a representation from various solid operations
var baseExtrude = new Extrude(Polygon.Ngon(6, 5), 6, new Vector3(0,0,1));
var void1 = new Extrude(Polygon.Ngon(4, 2), 7, Vector3.ZAxis, true);
var void2 = new Sweep(Polygon.Star(3, 2, 5), new Line((-5,0,3), (5, 0, 3)),0,0,0, true);
var representation = new Representation(new List<SolidOperation> { baseExtrude, void1, void2 });

#!csharp

// Create some elements with that representation.

var geometricElementModel = new Model();
var random = new Random(5);
for(int i=0;i<10;i++) {
    var transform = new Transform(i * 10, 0, 0);
    var geometricElement = new GeometricElement { 
        Representation = representation, 
        Transform = transform,
        Material = random.NextMaterial(false), 
    };
    geometricElementModel.AddElement(geometricElement);
}
return geometricElementModel;

#!markdown

To draw curves as elements, you can use the `ModelCurve` class. In fact, this is what has been happening under the hood when you `return` a curve directly in a notebook — we just automatically create a `ModelCurve` from it for you.

#!csharp

var curvesModel = new Model();
var u = Polygon.U(5,5,1);
for(int i=0;i<20;i++) {
    var transform = new Transform().Rotated(new Vector3(1,1,1).Unitized(), i*10);
    var color = Colors.Red.Lerp(Colors.Green, i/20.0);
    var modelCurve = new ModelCurve(u, new Material("curve", color), transform);
    curvesModel.AddElement(modelCurve);
}
return curvesModel;