Education_m_004 – Extrusions

Education Resources, Public Posts, Vectorworks jonathan

Extrusions are the main object in 3D modeling, so here are some rules for Extrusions. Extrude To create an extrusion start with a solid 2D element, for example a rectangle, a circle, etc. If you want to render the object it has to be a solid object before you extrude it. It can be a line, rectangle, polygon. It can be any 2D shape.

Extrusions follow a few rules:
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Download Imperial exercise files. (Vectorworks 2013)
Download Metric exercise files. (Vectorworks 2013)

Extrusions always are always perpendicular to the plane of the object. for some objects, this means that you have to change the view to get the extrusion you want.

Extrusions always start at 0 on the current working plane. If you haven’t set a working plane then this will the extrusion will start at Z=O on the current layer.

The extrusion is based on the 2D shape and this 2D shape is stored by VectorWorks. You can use the command Edit Group from the Organise Menu to edit the 2D shape and change the extrusion.

Extrusion Exercise 1
The first rule of extrusions as that extrusions are always perpendicular to the plane of the object. This means that you have to aware of the plane of the object as well as the view you are in before you choose the extrude command.

Open the file Extrude_1.sta from the exercise folder. There are 3 equal rectangles in the middle of the drawing.

Go to the Current View pop-up menu on the View bar.
Choose Top/Plan.

Select the first (left hand) rectangle.
If you look at the Object Info palette, you can see that this object is a Screen Plane object. When you extrude it, it will extrude perpendicular to the screen.

Go to the Menu bar.
Choose Model > Extrude…

Extrude this rectangle 2000mm (6’).

This rectangle has been extruded towards you, that is it has been extruded up.

Go to the Current View pop-up menu on the View bar.
Choose Front.

In this view you can see how the first rectangle was extruded up in 3D.

Select the second (middle) rectangle.

If you look at the Object Info palette, you can see that this object is a Screen Plane object. When you extrude it, it will extrude perpendicular to the screen.

Go to the Menu bar.
Choose Model > Extrude…

Extrude this rectangle 2000mm (6’).

This rectangle has been extruded towards you – in the front view.

Go to the Current View pop-up menu on the View bar.
Choose Right Isometric.

In this view you can see how the first rectangle was extruded up in 3D and the second rectangle was extruded towards the front.

Select the third (right) rectangle.

Go to the Menu bar.
Choose Model > Extrude…

Extrude this rectangle 2000mm (6’).

This rectangle has been extruded perpendicualr to the plane to the object, it has been extruded upwards.

Extrusion Exercise 2

One of the roles of extrusions is that Vectorworks remembers the original 2D shape used to create extrusion. This allows you to go back and edit your extrusion after you have created it, allowing you to change your mind about the shape of your model.
Open the file Extrude_2.sta from the exercises folder.

Double click on the extrusion. VectorWorks will take you into the extrusion so that the original 2d shape can be edited. Notice the orange border, this indicates that you are in side the extrusion.

Remember that if you want to edit an object in VectorWorks, double click on it.
Go to the View bar.
Click on the Active Plane pop-up menu.
Choose Extrude #1. This will ensure that the new shape adds to the existing object.

Add a circle to the 2D shape as shown.

When you finish the circle, depending on your Vectorworks settings, you will see a preview of the new object.

Select both objects.

Right-click (control-click with a one-button mouse) on one of the objects.
Choose Add Surface.

The two objects will be added together.

Click on the Exit Extrude button at the top-right side of the screen to see the results in 3D.

You can select several objects at the same time and extrude them. They don’t become a multiple extrude, they become an extrude group, a group of extruded objects. Edit Group will still display all the 2D shapes used to create the extrusion, but Ungroup will leave them as individual extrusions.
Multiple Extrusion
A Multiple Extrude is quite different from the standard extrusion. If you select 2 shapes and choose extrude, you end up with the two shapes extruded, like a group extruded. A Multiple Extrude is used to create 3D forms that change shape from one end to the other, or change shapes in the middle. You can use 2 shapes to create a simple 3D shape that changes shape from one end to the other or you can use several shapes and make a sort of skinned object.
Multiple Extrusions follow a few rules:

They always are always perpendicular to the plane of the objects. For some objects, this means that you have to change the view to get the extrusion you want.

Extrusions always start at 0 on the current working plane. If you haven’t set a working plane then this will the extrusion will start at Z=O on the current layer.

The extrusion is based on the 2D shape and this 2D shape is stored by VectorWorks. You can use the command Edit Group from the Organise Menu to edit the 2D shape and change the extrusion.

The stacking order of the objects (Front to Back) determines the shape of the Multiple Extrude. The object that is at the Back (or drawn first) is at the bottom of the extruded object. The object that is at the Front (or drawn last) is at the top, The stacking order can be changed at any time.

You can edit the length of the extruded shape using the Object Info Palette.

Multiple Extrusion Exercise

Open the file Extrude_3.sta from the exercises folder.

To create a chimney shape that changes shape from the base to the top, you need to draw the bottom shape and you need to draw the top shape.

Using the rectangle tool create a 1000x750mm (40×30 in.) rectangle with the insertion point in the middle of the rectangle and the coordinates at 0,0.

Tip: The easiest way to create a rectangle of a specific size and position is to double click on the rectangle tool. This opens a dialog box for you to type in the size and position of the rectangle that you want to create.

Draw a 750x500mm (30×20 in.) rectangle on top of the first rectangle so that they have their centers line up, that is they are aligned center/center.

Ensure that the rectangles are aligned.

Select both rectangles.

Go to the Menu bar.
Choose Model > Multiple Extrude…

Enter the extrude height as 3500mm (11’8”). This will create a slender tapered extrusion. As with all extrusions this object starts at 0 on the working plane and comes out of the screen at you.

In Top/Plan the object looks different. The chimney has just been created so it will still be selected.

Go to the Current View pop-up menu on the View bar.
Choose Right Isometric.

If the Object Info Palette is not open, go to Palettes on the Menu Bar and choose Object Info. The Object Info Palette allows you to make changes to the size of the extrusion, changing the shape ∆X and ∆Y, and the extrusion length. We want to change the height of the chimney. But we also want to see what the chimney looks like in 3D.

You can see your chimney in 3D.
It should still be selected, so go to the Object Info Palette and change the extrusion height to 1500mm (60 in.).

Double click on the edge of the object.
Although you are in a 3D view you are looking at the two 2D shapes used to make up the chimney.

Deselect everything by clicking away from everything with the 2D selection tool.
Right mouse click on the top rectangle (on a one button mouse use control-click).
Choose the option Send > Send to Back.

Depending on your options, you might see a preview of the updated multiple extrusion.

Click on the Exit Multiple Extrude Profiles button on the top-right of the drawing window.

Now you can see the results in 3D. As I noted earlier, VectorWorks uses the stacking order (the front to back order) of the objects to work out which rectangle to put at the bottom and which one to put at the top.