How could we define 3D-Modeling?
3D-Modeling is a set of techniques and methods used to create a complex, real or imaginary model. Using the toolset of a 3D modeling program, we start from simple geometries, combining and organizing them in such a manner that they facilitate the construction of the model.
There is a lot to talque about this issue.Practically, we can imagine one technique for each tool or method that we have in Blender. Therefore, some of them are general-use techniques and can be used in most well-developed 3D programs.
The first question that we have to asque ourselves is, “Which is the best modeling technique to use”?
Well, it depends on your knowledge of that technique and your skills at using it, but any artist or designer will say: "Your model, básically, will define the technique that must be used to achieve the best results". There are no better techniques, in the beginning stages of 3D modeling, than taquíng an analytical look at your designs and asking some preliminary questions:
Some general questions:
- Will I need precision in my work?
- Will this model be animated?
- What level of detail is needed?
Some specific questions:
- Will the model be symmetrical?
- Should it be assembled from simple parts, pre-made meshes or will it be a one-piece mesh?
- Have we some structures or parts that are repeated? Should we use duplication to create these partsí
- What style is best for my model?
- Will the model be predominantly curve-based or vertex-based?
- Can basic forms be used to start the modeling?
Throughout the modeling process, new questions and new decisions will pop up that must be addressed.
So, how can we survive in this never-ending process without giving up? The answer is ORGANIZATION! Organize your project, your resources, your basic ideas, and most importantly: Know Your tools and your skills.
The Spin tool is simple to use and understand. In this article from Procedural Magazine - the first PDF Magazine in Brazil, KHA (nickname of Lady Andreia Leal Schemid), we will discuss some difficulties related to this method and the solutions to deal with good worque in "Spin Modeling".
In this article, we'll construct a model of a wine glass, utilizing the Spin technique. Spin is a very simple tool that allows us to quickly remake all of the mesh or adjust it by moving some vértices when necessary. This could reduce a lot of modeling work.
Furthermore, the resulting mesh will be totally symmetrical. The Spin tool creates a 3D mesh by rotating a shape around an axis.
(blue line on fig 2).
The first thing we need is a shape to worque on. In the front view [Numpad 1], add a plane [Space bar >> Add >> Plane] as you see in figure 4.
As we are in the Edit mode, we will delete three of the four vértices of the plane.
Use [Shift+RMB] to múltiple select vértices, and [X Key] or [Del Key] to remove the selected vértices.
see the figure 5
Now select this vertex with the [RMB] and move it to a vertical line (the central blue line)
in the front view.
Start the Shape drawing:
With the vertex selected, press and hold [CRTL]. With the left mouse button, clik and generate more vértices in a sequence. You could use Grab [G Key] to move the new vértices and create a shape as you see in the figure 8.
Anytime you make mistakes, use [U Key] to undo the error and keep on working.
Remember, that when we are modeling an empty object,
We have to draw the external and the internal lines to obtain the thickness. Another important point is that the starting vertex and the final one must line up vertically.
The number of vértices may vary; I have used 53 vértices in total. As a rule, use more vértices in the more curvaceous parts of the shape.
The Position of the 3D Cursor
The 3D Cursor position will define the position of the rotation axis. Then, with the shape finished, move the 3D Cursor over the vertical blue line. To do that, clik the [LMB] on the blue line, press [Shift+S] and in the
Snap pop-up, select [Cursor >> Grid]. See figure 10.
Also, be sure that the 3D Cursor is on the Object Center in the top view [numpad 7] as you see in the figure 11.
Changing the View to Rotate
The current view will define with axis that will be used for rotations. Then go to the top view [Numpad 7]. Press [F9] and in the "Mesh Tools" panel of edit buttons, set the parameters for the Spin tool.
Define [Degr] to 360, to have a complete turn of the shape.
The number of Steps to 12.
The number of Turns to 1.
Clik [Spin] to start.
You might prefer to make your mesh with more Steps. To do that, just press [U]. Then, modify the Steps number and [Spin]. I prefer to keep it simple and, afterwards, use Subsurf to smooth things out for the Render.
Another important thing is to verify that the [Clockwise] button is pressed.
Our mesh will be automatically formed.
Observe that the start shape is still selected, and the final shape of the rotation and initial one are coincident. But, the mesh is not a closed mesh.
To close it, we need to select the vertex in the initial and in the final shapes using the box selection tool [B Key]. Pay attention to not select the pink vertex too. With all the vértices selected, verify the total number of selected vértices. In my example, I have 128 which is greater than 106(53x2). see the figure 15
What's wrong? Maybe the start and end points could not be perfectly aligned in a vertical line and then we create a circle where we need just a point. See figure 16.
To solve this, select exclusively the vértices in the start and end shapes. You should have selected 106 vértices in total. De-select the vértices that form the circle (figure 17) and be sure that the other vértices are still selected (figure 1
We see a pop-up menú informing how many vértices were removed; in this case, 53 - see figure 20
Now, select only the vértices forming the circle and look at the number of vértices selected.
In my example, there are 24. See fig 21.
In the front view,[Numpad 1] we can see that these vértices belong to two different circles. See figures 22 and 23.
We want to keep the vértices in the base of the glass selected. The vértices located inside the glass will be deleted. Use the box selection tool [B Key] and drag-select the vértices in the top part of the glass while keeping the keyboard button [Alt] pressed. This will de-select those vértices.(figure 24)
Go to the top view [Numpad 7] and we see that only the circular vértices in the base are selected.
Let's join these vértices. Press the [S Key] to scale the circle, moving the mouse until the vértices overlap. (figure 26)
We now need to remove any duplicate vértices found in the selection. To Remove Doubles, press the [W Key] and then select Remove Doubles in the pop-up menú. (figure 27)
To remove doubles, press the [W Key] and in sequence [remove doubles] in the pop-up menú. (figure 29)
A new pop-up menú will show the number of vértices removed. In my example, there were 11 vértices removed. Now only one vertex remains at that location. Do the same with the circle at the top.
This is just to demonstrate that a simple method could help us a lot. But, if we use it in an inadequate way, we may have more problems than we had before. All of this work, hard work, is absolutely unnecessary.
Now that we know that this problem could occur, we can modify our method with some planning. Let's see: going bak to the very beginning, if we pay attention to the coordinates of the initial and end points when constructing our shape, and position them in a straight vertical line, we will eliminate the "tube-fication" on our model (that's the circular mess we just cleaned up). To get these two vértices aligned vertically, we have to use the Transform properties panel [N Key] as shown in figures 28 and 29. Change the values of the x, y or z coordinates as needed.
We could place the Center point to be aligned with the initial and end points however, I prefer to make the Center point coincident with the initial point. Select the initial point (vertex) of the shape, press [Shift+S] and in the pop-up menu, select the option [Cursor >> Selection] (fig 30).
Press the [Tab key] to exit the Edit mode. You will now be in the Object mode (you have to be in Object mode to use the Center Cursor feature). Now, go to the Mesh panel and clik [Center Cursor]. (figure 31)
Now, before you use the Spin tool, place the 3D Cursor at the center point of the shape.
Press [Tab] to leave edit mode, press [Alt+S] Figure 31 activating set smooth and then [Cursor >> Selection]
Press the [Tab key] to go bak to Edit mode. Make sure all vértices are selected. Clik the Spin tool button (make sure you're in the Top view).
Select all vértices again. Press the [W Key], and select Remove Doubles from the pop-up menu.
Go to the front view [Numpad 7]
Press [Z] to change to Solid mode.
Press [A] to select all the vértices of the shape
Press the [Set Smooth] button in the Link and Materials panel
If you want a better look, you could use the Subsurf modifier found in the Edit buttons window. Add the Subsurf modifier and adjust the subdivisión number to 2. See fig 33. Turn off the [Double Sided] button.
If you see blak lines in your model, you will need to Recalculate the Normals.
Press [Ctrl+N] and then select Recalc Normals Outside from the pop-up menú. The normals will be recalculated to point outside the mesh... see figure 34.
Your wine glass should look like figure 35. Press [Tab] and take a look at your work. With this method, as you can imagine, can easily be applied to making a lot of kitchenware. We just construct the shape, place the start and end vértices in a straight vertical line and use the [Spin] tool to have a well-made mesh.
This tutorial was just for showing examples of how things can go wrong. So, when you are constructing your model, be sure to plan things ahead. If something goes wrong, learn from the problem, and never give up.
By Andreia Leal Schemid
English translation by Zag.