Transcript
Transcript
In this lesson, we will talk about selecting a portion of a mesh. To start, let’s import a mesh into our notebook by going to Utilities and then Import Mesh. For the path, I’m using pipe.OBJ, which you can download below this video.So, what I want to do, I’ll first type “Z” so that this is centered in my viewport. I’m going to go to my Block Details and to Display to turn off that wireframe. I want to first select this inner piping, and the best way to do that is with our flood fill options. In these text lessons, we’ve talked about the FE Boundary by Flood Fill, and we’ll also talk about that Filter Mesh by Flood Fill.So, if you were doing a simulation and wanted to define those boundaries, we could go to our Simulation Tab and go to our Utilities and choose this FE Boundary by Flood Fill, FE Boundary by Body, or FE Region by Body. I will instead be focusing on our blocks that select a mesh as opposed to an FE mesh. So, what I’ll do is search in my search bar for Filter Mesh by Flood Fill, and we’ll also be using our Remove Mesh Faces by Body.So, let’s start with this Filter Mesh by Flood Fill to select the faces inside of this pipe. So, for my mesh, I’ll make this a variable since I’ll use this in multiple blocks. So, I’ll right-click and make variable, which I will label Mesh. And I’ll place this in as my mesh for my Filter Mesh by Flood Fill. For the origin, I’m going to want to put this inside of my piping like so. And I have my angle at 45 degrees.To get a clearer sense of what this is, I’m going to go to my Block Details and that Display and change the color and remove that wireframe so we can see that just that one point has selected all of that inner piping. The way that our Filter Mesh by Flood Fill works is that the flood fill really shoots a ray at the vent and finds the intersection. If the direction is not given, it’ll choose that closest face to that point, and the first intersecting face becomes the basis for that flood fill. Then the flood fill compares the normal of that face with all the neighboring faces which are below the tolerance angle that we have here of 45.So, if we lower this angle, let’s say to 5, this is a pretty good face. So, if I move this origin so that it’s instead facing this flat face like so, I can see I’ve only selected these two faces, and I can move this around to select different faces.So, let’s select this face, and we have it in that hole. We can move this around, and if I decrease this angle, let’s say it’s 2 degrees, we can see that I’m not selecting as much of the mesh. So, if you wanted to increase or decrease how much you have, you can use that angle or that origin. So, I’ll place this back into that original hole that we had, like so.If I wanted to select a small portion of this mesh, what I could do is decrease that angle, let’s make this 2, 1, and we can see that it’s only selecting some of this piping. It’s not selecting those other faces. So, with the piping, it’ll still select a large number of it, but depending on your part, if it has some sharp edges, you might want to use that angle. But this is really a good block for getting an inside of a piping, for instance, different types of holes, something like that.You can also use our Remove Mesh Faces by Body. So, let’s try that. So, let’s start with that, where we will begin by placing that mesh into the mesh. And this body will allow us to select where we want to keep that mesh. So, for the body, I like to use a Box from Corners. You could use any implicit body though, and I like the Box from Corners because I can just quickly move one corner and change that other corner. So, I can select this whole region.So, we can see that it has selected all of them. I’ll again change this display. So, I’ll go to that Block Details under Display and switch out the wireframe and change that color. So now we can see I might need to move up my box a little bit more, but now I’m selecting this entire region. So that can also give you greater control when you are selecting a portion of the mesh, and you can also reverse that selection as well.So, those are two examples for selecting the mesh, and the same principles apply if you’re using that FE Boundary by Body block and that FE Boundary by Flood Fill. So, wherever the mesh and the body overlap, that is what selected for that Remove Mesh Faces by Body and the FE Boundary by Body and the FE Boundary by Flood Fill, same process as that Filter Mesh by Flood Fill.