I’m attempting to model some polyhedrons, following instructions meant to be used with Maya. One operation is “poking” faces. Is there a blender command corresponding to this? Unfortunately, I’m not sure exactly what the poking does…I think it puts a vertex in the middle of the face and moves it towards the center, but I’m not sure…
It in the way I’m trying to use it, it’s an easy way to go from one of the platonic solids to other semi-regular polyhedrons.
I know this is a really old thread, but I thought I’d respond for posterity.
In my experimentation to create a great dodecahedron, I discovered this workflow to “poke faces.” I’ll describe it using a great dodecahedron as an example. First, create an icosphere, subdivision 1. This is an icosahedron.
Now go to edit mode and select all faces. Extrude, and choose individual faces as the mode, then move the faces outward a little. Complete the extrusion, and then press ALT+S (expand/shrink). This will have the effect of scaling each face almost independently. That is, instead of scaling to the center of the solid, each triangle will scale to a point somewhere outside of the center. Shrink the triangles down until they are as close to a single point as you can, and then complete.
Now remove vertex doubles. Congratulations, you have completed a maya poke. The one clunky thing about this workflow is that when you finish, nothing is selected. So if you want to modify the poked vertices (such as to scale them to make a correct great dodecahedron), you have to select them. It’s sort of a pain, but it’s an improvement on the previous methods to poke faces, since you can poke hundreds of faces at a time.
This may save you a few steps, if you measure a line of the icosahedra before extruding,then go back and select all and proceed with the extrusion you can numerically enter that data after the Ekey, followed by the rest of your work flow without having to reselect anything.
That’s a good idea, but unfortunately I don’t think it works in this case. The problem is that the ALT+S shrink command doesn’t scale each “sub-triangle” locally… they still all move somewhat toward the object’s center point, but not as much as a normal scale operation.
I did have one more idea that I haven’t tested that might work too. When you create the icosahedron, select all vertices in edit mode, then save a vertex group. After you poke the faces, select all vertices again, then UNselect the saved vertex group. I haven’t checked to see if this works yet, but it seems like it should.
Well, if you wish to be a perfectionist, yes you are correct. And vertex groups may be a good approach to try as I did note what you were saying. Also please note that Edge angles are off by a bit with your starting subdivided icosphere and therefore so are the edge lengths. A minor error at first, but multiplies as you progress in your construction.After all, you are trying to make a geometric object symmetrical. Well, just for fun, I constructed one using the " the old fashion way" by first intersecting 3 golden ratio rectangles at their centers thusly and then played connect the dots.
The results weren’t any better.
I guess that blender just has to start rounding off infinite numbers somewhere, I have no idea of the precision. Not too bad though, the face areas were all the same and I really don’t think that anyone would notice in a render anyway.
I liked your approach to the problem. Let us know how it goes.
Wow, that’s really interesting that the edge lengths are so different. I wouldn’t expect the error to be so high.
I tested the vertex groups method, and the way I outlined above does not work. However, if you make the vertex group when you extrude the faces (and only the extruded faces are selected), then you have the poked-in vertices in a group when all is finished.
Yes, very nice. I don’t know why my edge lengths came out the way they did. I tried it again this morning and they came out the same. I must have fat-fingered something. It’s amazing what a night’s sleep can do!
Yes, you are right about the scale factor - I just did it by eye. If I (like pixelmass ) had not been posting last thing at night, I would have realised that the right way to do the scaling was with the aid of a construction line.
Select two non-adjacent vertices of the original icosahedron, and F to connect them with a line: