The first step in headlight design is generally to thicken the cas surface sent by the OEM. There are many ways to thicken, but there are generally two ideas. One is to directly thicken the surface to a certain thickness after sewing. Thickness, the other is to stitch the sheet into a closed surface, and then use the closed surface command to turn it into a solid. When using the first method, don’t try to sew all the pieces together and thicken them directly. This is often impossible. For example, if you have a curved surface with R=2mm, you need to thicken it to 2.5mm. This cannot be done, so it is generally used to thicken the large surface and use Boolean operations to turn it into a solid, and then extract the surface to trim it. Below I use an example to illustrate.
First on the renderings
From left to right, the commands that use the bridge surface and fill surface, the command that uses the trim command, and the command that uses the closed surface command.
The first method - mainly using bridging and filling
The history tree of its entity is as follows:
I first cut several large faces and then directly thickened them
and then joined the arc faces. However, because the initial faces are relatively poor, I used bridge or fill commands between some faces. . Smooth the curve before bridging or filling, so that the resulting surface will be better, but it is not absolute. The few I bridged are not good-looking.
After connecting all the circles, you can use the cutting command (if you can’t cut, you can pull out the surrounding surfaces, and the surface and the body cannot be tangent or not completely cut), and the other is to add the surface in reverse. Thick, and then use the remove command to make the arc out, here I use the second method.
The downside of using this method is that the faces don't look good.
The second method - the way to use the trim command
Its operation process is basically the same as the first one, the main difference is the way of joining between surfaces. This method is to extend the surface first, and then extract the edge of the other side, and divide it or cut it in pairs. This method can only be used when the two faces have obvious intersects, otherwise you still have to use the fill or bridge command.
Most of the noodles obtained by this method are better looking and can achieve the same effect as the original cas noodles.
The third method - the way to use the closed surface command
The history tree of this method is as follows:
the entity looks relatively simple here, but it is more complicated in the face operation. This is relatively simple, just offset several large faces and then trim and sew them together.
The surface obtained by this method is the best-looking among the three methods, but it is also the one with a relatively large amount of work, especially when there are a lot of curved surfaces.
Summarize
1. But in the actual operation, it will first break the reference extraction surface -> cancel trimming -> trim and cut if it can intersect, and find a way to bridge if it can't.
2. If some faces cannot be extrapolated, extended and trimmed, then extract the edges and fill them.
3. Use the repair command less. After using it, the surface is not easy to be biased, and it is easy to report an error, but it can also be used when time is tight. Everything is based on reality. The error of the joint command should be within 0.005, because if it is too large, it will also lead to poor operation in the future.
4. Sweeping in the direction of draft is very useful, and it is a great helper for faceting.
5. Try to operate the rounding on the entity as much as possible. If it is operated on the sheet, it will be inconvenient to modify it later.
6. In addition to the above-mentioned commands of joining, canceling trimming, smoothing curves, extracting, extrapolating, offsetting, and sweeping, the commands that must be mastered at the first time are projection, intersection, and connection curves. command, these will be used in the step of thickening the surface.