Working With Profiles | SelfCAD
by Szymon Śliwiński in Workshop > 3D Printing
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Working With Profiles | SelfCAD
Welcome, nice to see you in the next SelfCAD tutorial!
In SelfCAD we have two types of objects - meshes and profiles. The basic difference between them is that meshes are composed of polygons and profiles are actually sets of edges. It means that the profiles have no volume and you cannot print them but you can use them to model many interesting printable meshes.
Copying the Edges
Since each profile is composed of edges, you can easily add one to the scene by selecting several edges of any mesh and copying them.
3D Sketch
To draw profiles in SelfCAD, we use the 3D Sketch tool. Once you click it, you will find 8 subtools: Line, Spline, Arc (3 types), Text, Circle, Square, Ellipse, and Donut. Below the subtools, but above the line, there are subtool settings. Below the line, there are sketch settings that apply to the drawing process. These settings depend on the mode you use - "Planes" or "Objects". Read the next steps to learn more about each option.
3D Sketch: Line
The first subtool you can use is the Line sketch. It simply draws straight lines. Each click in the workspace creates a new vertex, endpoint of a single line. Note that you can also enter values like length manually.
For line, we can set a number of edges and symmetry.
Number of edges allows us to additionally divide each part into shorter segments. The first picture shows two lines, drawn with No. of edges 1 and 5.
When symmetry is turned on, the main workspace axes become also the axes of symmetry. Look at the second picture. One of the green shapes was drawn with Y-symmetry enabled, the blue one with Z-symmetry and red with X-symmetry. This is how their mirror images were created.
3D Sketch: Spline
If you need to draw a curve, use Spline. It creates a smooth path connecting the chosen points.
Remember that all curves in SelfCAD are in fact composed of many short edges. And here we have the smoothness parameter. Look at the image. The first spline was drawn with smoothness set to 1, the second one with smoothness 30. Do you see the difference? The second spline is made from much shorter edges. It looks better but requires more memory!
3D Sketch: Arc
Arc is a part of a circle. In SelfCAD there are 3 useful types of arc drawing called 1, 2 and 3 Points Arcs. They differ in order of points you have to click.
1 Point Arc:
- Center of the circle
- First endpoint of the arc
- Second endpoint of the arc
2 Points Arc:
- First endpoint of the arc
- Second endpoint of the arc
- Middle point of the arc
3 Points Arc:
- First endpoint of the arc
- Middle point of the arc
- Second endpoint of the arc
If you know the radius of the arc you're about to draw, you have to use 1 Point Arc.
In settings, we have number of edges and symmetry again. Note that it's number of edges, not smoothness. It means that if you set for example 12, an arc will be composed always of 12 edges, no matter how long this arc will be.
3D Sketch: Text
You can also use Profiles to write a text! Just enter your text to the text field, choose a font and drag your mouse in the workspace. You can also set the smoothness and draw with symmetry.
3D Sketch: Circle
Circle is definitely one of the most common subtools in 3D Sketch. The first click in the workspace creates the center of the circle, and the second one defines its radius.
Do you remember what I told you about the number of edges in Arc description? In the photo above there are 3 circles with different No. of edges values. Note that you can also use circle to draw shapes like triangle, square, pentagon, hexagon and so on.
3D Sketch: Rectangle
Rectangle, another useful tool, is composed of 4 lines. It's logical, right? I told you about it because No. of edges can be a bit confusing. You set there a number of segments to which each side of rectangle is divided
3D Sketch: Ellipse
Sometimes we need to draw an ellipse and there is the tool also for this. Drawing the ellipse requires three mouse clicks. And here we have one important difference between circle and ellipse drawing - the first point belongs to the shape, it's not a center. The second chosen point defines one of the diameters of the ellipse. The third click specifies the length of the second radius.
3D Sketch: Donut
Donut draws two ellipses. The second one has two times shorter diameters that the drawn one.
3D Sketch: Plane Settings (Offset and Rotation)
Look at the first image above. When we draw profiles in Planes mode, we draw them... well, on planes. The plane in the picture is a Bottom/Top Plane because it's perpendicular to the top and bottom view.
The most interesting thing here is that we can change the height at which the plane is located and also rotate it. Now, look at the second image. The circle in the middle was drawn with higher offset value and the last circle with even higher offset and rotation.
The last picture shows how the magnet tool works. Choose it by clicking on the button next to the offset slider and then select any existing point to place the plane at the same height.
3D Sketch: Plane Settings (More Planes)
You can display more planes. The basic three are Bottom/Top, Left/Right and Back/Front, but you can also add more planes. Look, if you change the offset and rotation of any plane, you can save it as a new plane. Then the plane is added to the list of planes and you can display it too.
If you don't like the B/T_1 name you can change it to your own. Just click on the blue Bottom/Top text before saving or, when the plane already exists, on its label above its settings. Now you can name your plane My Plane or Steve, for example.
3D Sketch: Profile Settings
One of the profiles' advantages is that you can always draw new shapes inside the existing object.
Look at the first image. I drew lines, created a new profile in Profile Settings and then drew circles. This is how lines and circles are two separate objects. The same result you can achieve by deselecting the active profile in the list of objects, that's why you may never use the Profile Settings. However, it can be helpful if you have many objects in your project.
You can change the names of your profiles using the list of objects (Picture 2).
The last profile I drew was Text. But now I can select the Circles profile in the list of objects or use Profile Settings and draw more circles inside the existing profile (Picture 3).
You cannot have profiles and meshes in one object!
3D Sketch: Precision Settings
One of the key problems in the drawing is precision and that's why we have Precision Settings, according to me the most useful set of settings.
First of all, we can snap to vertices and edge centers of existing objects:
- Active profile - snaps the drawing to itself
- All profiles - snaps the drawing to other profiles
- Objects - snaps the drawing to meshes
- Grid vertices - snaps the drawing to points of intersection of the grid
- Guides - snaps the drawing to guides
Below, there are two important checkboxes - Minimum Step Size and Minimum Angle Step.
Minimum Step Size causes that lines can have a length that is only a multiple of this parameter. When you check it, the new checkbox appears - Override Steps Size. You can see how it works in the second and third images. When you snap to an existing point, like grid vertex, the line will still have a length that is a multiple of minimum step size (Picture 2), but if enable the Override Steps Size option, the line will be snapped correctly (Picture 3).
Minimum Angle Step is similar, but it works with angles.
In precision settings, we can also hide or unhide other objects.
3D Sketch: Objects Mode and Wrapping
In Objects mode, there are only Profile Settings and Precision Settings, without Plane Settings. It's because we don't draw on planes here but meshes. But what will happen if we draw start drawing a profile on one polygon and finish on another? Here's where wrapping comes into play. To understand how wrapping works look at the images above. We choose where the profile should start and end, but when it's created it is not flat. Instead, the mesh is wrapped in the profile.
Regions Selection and Intersection
When lines intersect inside one profile, the new vertices are created in points of intersection. Furthermore, these points divide the profile into paths. To select a path, you can use face or polygon selection (Picture 2). It often happens that you need to select edges (Picture 3) or vertices (Picture 4).
The intersection is still in beta so there is no guarantee that everything will work.
Deform Tools
Deform tools work for 3D profiles just as they do for meshes. If profile is flat (2D), some tools will be unavailable.
In the picture, you can see the results of several deform tools used on the same cylinder (black). By the way, as you see, you can also change the colors of profiles.
Extrusion and Inset
Both Extrusion (M+E) and Inset (M+I) work the same and modify the profile in the vertical direction.
Add Thickness
Add Thickness (M+A) tool modifies the profile horizontally.
Resolution and Add Details
If you need less or more vertices, you can use Resolution (M+L).
It is also possible to add new vertices or even new edges manually using Add Details (M+D).
Cut With Profile
Looks like finally something useful, right? Yes, Cut with Profiles (M+P) is a very powerful tool. To use it you have to select both a mesh and profile which is drawn on this mesh and then choose Cut with Profile. Now we can delete the profile to see better what happened. As you can see in the second image, the cube has completely new edges where the profile was.
When we try to use Polygon Selection the entire surface is selected, because it's one flat polygon, it's true. It would be great if we could select only the inner parts and, for example, extrude it. And we can! Look at the fourth image. We can open Selection Settings, turn on Part Selection, and then select a polygon which is a part of the entire polygon. You can recognize parts by thick, blue edges.
Copy Offsets
When talking about profiles, I have to show you how Tools work because they are definitely the most interesting.
First is Copy Offsets (T+O), which works normally, like for meshes. Nothing special.
But now...
Fill Polygons
Now, we finally use profiles to generate meshes. The first great tool is Fill Polygons (T+F), which generates polygons inside the closed profiles. When these polygons can be extruded, modified, deformed, etc. You may say now, that we can use Free Hand and get the same result. Well... yes, but actually no. So what's the difference? 42 is the answer.
Look at the second picture and note that 4 is filled. To delete the inner part, we can use Part Selection and select only the unnecessary polygon
The last photo shows what else you can easily create thanks to the fill polygons (+ add thickness, extrusion and cut with profile)
Revolve
Revolve (T+V) is an absolutely powerful tool for profiles. Look at how it works.
I drew a profile from Picture 1. It was half of a glass. Then I used Revolve and I got a 3D mesh. The problem was that the axis was in the wrong place, so I clicked on the Revolve Around Edge button and selected the correct edge. This how I easily modeled a quite nice looking glass. When the mesh was ready, I used the Round Object tool to make it more smooth.
Loft
Loft (T+L) is a really amazing tool that allows you to create fantastic shapes, especially with profiles. To use it, just draw at least two profiles and choose Loft. In tool settings, you can change many parameters if the created mesh. A very interesting option is adding a bevel shown in the last image.
Follow Path - Two Profiles
Follow Path (T+P) can be used in two ways - using two profiles or a profile with mesh.
To show how this tool works for two profiles, I will model a photo frame. In the beginning, I need two profiles: one profile will define the shape of the frame cross-section and another one will define the path, which here should be rectangular (Picture 1).
In this tool, the order of the selected profiles is important, because the first object follows the second one. So first we have to select the cross-section and then the rectangle. With these profiles selected we can use Follow path (Picture 2). If your frame doesn't look as you want, you have to close the tool and rotate the cross-section. Then you can finalize the tool to create mesh.
Follow Path - Mesh and Profile
When you use Follow Path you don't have to remember about the right order, because the profile will always be a path. There are two types of the tool for profile+mesh, duplicate and wrap.
Merge and Split
Sometimes we have to merge several profiles into one or split one profile into two separate objects. For these operations, we can use Merge (U+E) and Split (U+S) tools