Blender Newebie: Extrusions, Drawing Polygons, Parallel Asymmetry & Snap Grid

I only downloaded Blender yesterday - and after a few tutorials and some horribly misshapen cubes, I’m ready to start making my first model: A simple wall panel. First of all, starting with a cube is great and all, but the wall panel is not going to be rectangular - it’s going to have triangular and hexagonal features. So far, no tutorial has shown me how to draw a plane through a 3D object, cut it, and make new vertexes, edges, and faces. Does this function exist? “Take a cube and slice off a corner” seems like a pretty basic operation for a 3D modelling program. I tried deleting a few vertexes, but that messed things up horribly. Another issue I am running into: Parallelism. I don’t know how to align a face or an edge to another and get a specified angle - say, 60 or 45 degrees. Mirror might work, but this wall panel is going to be asymmetric. Does Blender have a snap grid? Additionally, there is the problem of greebling. After watching a dedicated greebling tutorial, it seems that Blender lends itself very well to ‘additive’ greebling - taking a flat surface and adding volumetric geometry on top of it. However, for the grooves I have planned as greebling in the wall panel, I will need to cut away pieces of the geometry, instead of adding more on top of what already exists. It seems like the extrusion tool can do this, simply by extruding inward instead of outward - but how do I do this without going through subdivide hell?

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You can trace your plan by adding vertices:

  1. Load your plan as a background image by holding your courser on the 3D window and press N on your keyboard. A menu appears on the right side of your 3D window, scroll down until you see “Background Images” Tick and open it load your plan and adjust the size and location.
  2. If your plan is loaded as front view hit 1 on your Number pad and add a plane you can add single vertices by holding down Strg or Cntrl and click with your left mouse button. You can also extrude by pressing E.
  3. When you in Grabbing mode (press G) you can hold down Strg so what ever you are grabbing (moving) will snap to grid

I hope this could help you but there are plenty of good Tutorials about it on Youtube to help you to get the hang of it.

Good luck and have fun with it.

I only downloaded Blender yesterday - and after a few tutorials and some horribly misshapen cubes, I’m ready to start making my first model: A simple wall panel. First of all, starting with a cube is great and all, but the wall panel is not going to be rectangular - it’s going to have triangular and hexagonal features. So far, no tutorial has shown me how to draw a plane through a 3D object, cut it, and make new vertexes, edges, and faces.

There are a couple of ways to approach this. One is to use the knife tool, cut through the edges, and delete the vertex you want to eliminate. Another is to select the thee edges that are going to be cut by the plane, subdivide them, and move the vertices created by the subdivision to where you want them, and delete the corner vertex, In both cases, you’ll need to create a new face.

I don’t know how to align a face or an edge to another and get a specified angle - say, 60 or 45 degrees.

I use “helper geometry” for this. If I need a 45 degree angle, I add a plane or a cube aligned in such a way that the diagonal is the angle I’m looking for. The diagonal is then 45 degrees. If I need an angle of another size, for example 60 degrees, I add a temporary circle or cylinder mesh with the number of sides to create the angle. For a 60 degree angle, a three sided “circle” is an equilateral triangle.

Does Blender have a snap grid?

Yes. SHIFT-Skey activates the Snap menu, and the first option is “selection to Grid”.

However, for the grooves I have planned as greebling in the wall panel, I will need to cut away pieces of the geometry, instead of adding more on top of what already exists. It seems like the extrusion tool can do this, simply by extruding inward instead of outward - but how do I do this without going through subdivide hell?

I would use loop cuts. Create a loop cut on each side of where the groove is to be, and extrude the faces to be grooved inwards.

ns

You don’t have to use the cube, there are a lot of other primitives and other shapes are available through addons. It’s also possible to make an empty mesh by deleting all vertices (and therefore all edges and faces too) and add new ones by ctrl clicking. It extrudes edges/faces based on last selection, or adds new vertices if nothing is selected. No tutorial will show you how to model by cutting an object with another, because that’s not how polygonal modeling is done. Boolean modifier can do that but because how vertices, edges and faces are ordered actually matters, it’s usually used as last resort or kept in the modifier stack. It’s also possible to cut a mesh using a 2D object using a knife project tool, but that is also something that polygonal modeling is not based on. What you do is plan ahead and use loop cut (ctrl+R) quad faces, subdivide edges/faces (W -> subdivide), inset (i) faces, knife cut (K), extrude (E), bevel (ctrl+B), duplicate (shift+D) and all other nice tools to put in geometry that can then be used to edit further to make actual shapes, holes, or whatever. There’s no one way of getting there and there are different modeling tools, styles and workflows that can be used and/or combined: box modeling, poly-by-poly modeling, sculpting & retopology, using other types of objects and converting them to mesh, using other types of objects as helper objects, simulations, duplication. One way of aligning an edge to another is to use edge slide and its align options. Select an edge, GG (pressing G once moves, pressing it again slides) and then E to make it even with adjacent edge, and F to flip. You get spesific angles by rotating ® and holding down ctrl(+shift) you get angle increments. How it rotates depends on what the pivot point is. You can view face angles by enabling their display from the properties panel (hotkey N), under mesh display. There’s also shear tool (ctrl+alt+shift+S) that you could use. Snap to grid is in snap menu (shift+S), and there’s also increment snapping mode (ctrl+shift+tab) for snapping tool. There are different ways to make indentations: model them in by adding and arraging vertices and use extrude. Model one in, delete geometry around the indentation shape, duplicate it to make more and then fill the gaps my forming faces between vertices/edges. Another way is to use texture to either move the geometry (displacement) or make it appear as if there was an indentation (normal map, bump map) for things that wouldn’t make sense to model in. Or you could resort to using boolean modifier.

By the way. If you notice the value in using paragraphs and meaningful pictures, then use them next time.