You joined 2 roofs together and you wonder how you can cut the main roof to create a dormer opening.
Well, I always use one of the 3 following options. Depending on the situation and the complexity I choose the right one.
- Dormer Opening: easiest one to use:
First click the main roof (1), then select both sides of the secondary roofs (2)(3).
- Modify sketch of main roofAfter joining the roofs, edit the main roof and draw non-sloped sketch lines around the secondary roof:Here the sketch lines in plan view:
- In Place Family. In this case we will draw in an in place family a void that will cut the roof. In complex situations this gives us the most control.
First you need to select a category for this new family. This is important because your family will be drawn according to the visibility settings of its category and it will appear in schedules of this category. For example if you don’t want that your family, that will only cut the roof, will appear in a roof schedule you need to choose here another (more generic) category.
Then you need to name your new family. This is for example important to recognize your families in schedules.
Then choose the type of 3D Void you want to create. Because we want to cut the main roof, choose an option in the Void Form flyout menu:
In this case we will create an extrusion.
Before drawing the sketch lines we need to define first the workplane. To define a workplane you can draw a reference plane in plan view first, but in this case I’m going to use the vertical border of the roof as my workplane.
Then draw the form of the dormer opening (if possible use the “Pick Lines” tool in the “Draw” toolbar and pick existing object edges).
Click on “Finish Edit Mode” to create the Void Object.
AFTER DOING SO, DON’T YET CLOSE THE FAMILY. YOU NEED TO CUT THE MAIN ROOF BEFORE SAVING THE FAMILY.
First, orbit the camera to get a view of the underside of the roof.
Drag the handles of the void to include the portion of the main roof you want to cut.
Use the “Cut” tool and select roof and void in any order.
Finally, close the family and enjoy the result …