The back side of a face shows up as a darker shade. For basic modeling, this isn’t really a problem, but sometimes you’ll want uniformity in the way your model looks, or you’ll need to export models to rendering software, and if you don’t have materials on the right side of your faces, they won’t render properly. This is why sometimes in your model you’ll have faces that show up as a dark color, and faces that show up as a light color. In SketchUp, faces have a front and a back side. There’s one more thing about faces that I’d like to talk about. SketchUp will automatically “heal” these two faces by merging them into one like they were before. If you decide that you don’t want this face divided into multiple faces, you can go back and erase this line. SketchUp will always automatically divide a single face into multiple faces if you draw a line across it. If you take a line and draw it down the middle of the triangle, SketchUp automatically divides the face into two faces. Let’s say that for whatever reason, you decided that you wanted to divide this triangle in half into two triangles. If you just re-trace one of the lines (draw over top of the existing line), then SketchUp will put this face back into your model. The nice thing about SketchUp is if you delete this face, it isn’t gone forever. This will delete the face between the bounding edges and just leave you with 3 lines.
![sketchup make face from lines sketchup make face from lines](https://aws1.discourse-cdn.com/sketchup/original/3X/8/7/87865da34e6cf7e473a0f2dfa3e1792e24231032.gif)
Now that we have the face selected, press the “delete” key on your keyboard. This indicates that your face is selected. The face on the inside of your triangle develops a blue shading. Now, click inside the triangle on the face – what happens? Close it back in so the SketchUp creates a face inside of it. For example, let’s use the triangle that we drew up above. You can use the select tools to select a face in SketchUp just like you would a line. You can’t stop SketchUp from creating faces between coplanar lines, but what you can do is delete the faces. Occasionally, you’ll want to have groups of lines in SketchUp that are coplanar and intersect, but you won’t want a face between them. What happens if you erase one of the bounding edges of this shape? As you can see in the image below, if you erase one of the bounding edges, we no longer have the prerequisites for a face in SketchUp, so the face disappears. The lines around the shape are called the “bounding edges,” because they are the lines that make up the outside boundary of the shape. If I start with two lines, as shown below, then draw a third line between the two end points, what happens?Īs you can see, as soon as this shape is closed, SketchUp automatically creates a face between these three points because it now has the 2 prerequisites required to create a face – at least 3 coplanar (meaning on the same plane) lines and a closed shape.
![sketchup make face from lines sketchup make face from lines](https://aws1.discourse-cdn.com/sketchup/original/3X/6/9/69f62224f500c187dabc188a2c48cb9272d1a10e.png)
Let’s say that we draw a triangle using the line tool. In order to draw a face, SketchUp must have at least 3 lines that create a closed shape on a 2 dimensional plane (meaning that the 3 lines must all intersect at some point). Faces are two dimensional areas that are drawn between lines. The other kind of objects that exist in SketchUp are faces. They don’t have any area, they simply have a length. At their most basic, these basically travel in one path between two points. Lines are the objects we created in our first tutorial.
![sketchup make face from lines sketchup make face from lines](https://help.sketchup.com/sites/help.sketchup.com/files/images/fg005_3.png)
In order for us to move forward, I want to talk a little bit about the way models in SketchUp are made up.Įvery model in SketchUp, when broken down to its basic building blocks, contains two types of objects. In part one of my 2D SketchUp drawing tools tutorial (visit that tutorial by clicking here), we talked about using the 2D drawing tools to create lines.