Essential Blender- P6

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Essential Blender- P6

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Essential Blender- P6: You may copy and distribute exact replicas of the OpenContent (OC) as you receive it, in any medium, provided that you conspicuously and appropriately publish on each copy an appropriate copyright notice and disclaimer of warranty; keep intact all the notices that refer to this License and to the absence of any warranty; and give any other recipients of the OC a copy of this License along with the OC.

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  1. Figure 1.27: The Constraints panel in the Object buttons. You could have used the "Add Constraint" button in this panel to do the same thing you've just done in the 3D view, but you would have had to fill in the proper object name in the panel's "OB:" field to get things to link up properly. Using selections and the Ctrl-Alt-C hotkey builds the constraint for you automatically. Tip: Ctrl-Alt-C brings up the Constraint menu, which adds a constraint to the Active object, using the other selected object as its target. What is the final effect? Move the new empty back to its original position (just using G to move it by hand will surely be close enough, but if you'd like to practice your precision movement, you can always use the Shift-S snap method described earlier). Play the animation. The new Empty rotates, without any keys, so that it always points to ("tracks") the electron to which it is constrained. Its child electron, in turn, follows the Empty's rotation, most likely generating some neat orbital motion.
  2. Finishing Up Use Shift-1 (or Shift LMB on the layer 1 button) to add Layer 1 back to the display. Play the animation to see it in all its silly glory. While the animation is playing, you'll learn one more trick. Let the animation run, and as it plays, try using the MMB-drag in the 3D view that you've used before to rotate your view. It works while the animation plays back! The other view translation controls work as well, although you'll have to use Ctrl-MMB for zoom, as the scroll wheel won't work in this mode. Now that you've made three protons, three neutrons and three electrons in orbit, you have yourself a finished atom. If you would prefer to have some more practice, add some objects to the nucleus and toss in some more electrons until you have the element of your choice. Rendering for Animation In the Interface chapter, you rendered a still of the default cube which was, without a doubt, thrilling. Since you've just animated a nucleus, let's render it and watch it move. On the far right of the 3D window's header (you may have to MMB-drag the header to see it) is a small Render icon. LMB click it.
  3. Figure 1.28: The Render icon on the 3D header. Almost instantly, the render window appears with a preview image of the Scene, drawn in whatever style (solid/wireframe) and from whatever perspective the 3D window is using. This sort of preview render (technically, it's called an "OpenGL" render) can be triggered from any 3D view by LMB on the render icon in its header. Now, Ctrl-LMB on the same render icon. This time, the preview seems to animate, albeit slowly. What it's really doing is creating 250 OpenGL preview images and saving them somewhere (secret!) on your hard drive. If you don't feel like waiting for this to happen, you can cancel it (or any render, even one with a single frame) by pressing the Esc key. When it has finished making the preview renders, you can press the Esc key to go back to the main Blender window. From there, find the Scene buttons (F10), and press Play.
  4. Figure 1.29: The Play button in the Scene buttons. A new window opens and your animation will play in a continuous loop. Okay, that was the fast, crummy OpenGL preview render. It's great for checking your animation to make sure that everything is moving correctly, but not nearly suitable as a final product. Chapter 12 contains full instructions for rendering animations to disk, so we're just going to take a shortcut here: Zoom outward in the 3D view until you can see the Camera. RMB select it. Now, with the mouse still over the 3D view, press Numpad-0 to switch to the view from the camera.
  5. Figure 1.30: The camera's view of the atom. The outer solid border in this view represents the camera object itself and should be pink. If it's not, then you may not have the camera selected (just RMB on the solid border to select it). At the moment, your atom is most likely not in the center of the camera's view. Press the R-key twice to put the camera into an "aiming" mode and fiddle around by moving the mouse until your atom seems to be reasonably in the center of things.
  6. Figure 1.31: The camera is now aimed a little better. If you're up for it, and you have some time to kill, press the Anim button in the Scene buttons (F10). Blender will begin to actually render your scene, frame by frame. Even on a speedy computer, this will take several minutes, so go get yourself a drink. When it's done, press the play button again to see the finished, rendered animation. It doesn't look so hot, does it? Even rendered. Don't despair - you haven't learned modeling yet, or materials. Or lighting for that matter. But you know the basics of working with Blender objects and animation now, so the rest will come easily.
  7. Chapter 4: Mesh Modeling Discussion By Kevin Braun Introduction What is Polygon Modeling? Polygon, or "Poly," Modeling is the process of creating a 3D model using basic 3D elements called vertices, edges and faces. A vertex (more than one vertex are called vertices) is a point in 3D space. An edge is a line connecting two vertices. Three edges together form a triangle face, while four edges together form a quad face. Those triangle and quad faces of filled space are the polygons. Fig. 1: A vertex, an edge, and a face. One of the main advantages of polygon modeling over other modeling methods is the ability to easily add detail to specific areas without having to add more complexity to the rest of the model. Other advantages include speed of rendering in real-time environments and relative ease of texturing. Modeling Tools Working with Vertices Selecting / Deselecting The first thing you'll need to know in order to begin modeling is how to select and deselect vertices. Run Blender, or if it's already running, clear the current scene with Ctrl-X. There should now be a square in the center of your screen, highlighted in purple to indicate that it is selected. In the introductory chapters, you worked with objects in Object mode, and always used the Tab key to leave Edit Mode when an object was created. Now, we want you to actually work in Edit Mode. So, use the Tab key to enter Edit Mode with the default cube still selected, and you'll see that the four edges (straight lines) and four vertices (points at each corner) that make up this polygon are highlighted in yellow.
  8. Tip: The Tab key toggles between Edit and Object modes. If you press the A-key with your cursor in the 3D viewport, you can toggle between selecting and deselecting all of the vertices in this object, just like you could when working with multiple objects in Object Mode. Putting an object into Edit Mode makes it function in many ways like a mini-version of the whole scene - a lot of what you have already learned will apply within this new, smaller scope. Make sure all vertices are deselected and then right click on the vertex in the upper left corner to select just that one. If you now right click on the vertex in the lower left corner, the one you previously selected will become deselected and the lower one will now be selected. You can select (or deselect) multiple vertices at the same time by holding the Shift key down while right clicking (RMB) on each vertex you would like to select. Tip: In Edit Mode, selection works for vertices just like it does in Object Mode: RMB selects, while Shift-RMB builds and takes away from the selection. Fig. 2 Deleting
  9. The next thing you'll need to know is how to delete a vertex. First you'll want to get a good look at all the vertices that are in this object. By pressing Numpad-5 you can toggle your view between Perspective and Orthographic view (see Chapter 2 for more on the difference). Switch over to perspective view and use the techniques you just learned to select all of the vertices except the one in the upper-most left corner and then press the Delete key (or the X- key). A menu will appear with a number of different options - this is where things start to differ from object mode. Choose "Vertices" from the menu to delete the vertices that you have selected. You may notice that a side effect of deleting the vertices is that the edges and faces are also deleted. This is because the faces are made up of edges and the edges are made up of the vertices you just deleted. Removing the vertices necessarily removed the other things they had built. If you had chosen "Edges" or "Faces" from the Delete menu you could have removed only the edges or faces respectively, leaving the vertices in place, but unconnected. Tip: X-key or Delete key brings up the delete menu, allowing you remove vertices, edges or faces. Fig. 3.Ortho: Orthographic view.
  10. Fig. 3.Perspective: Perspective view. Moving At this point you'll want to move the remaining vertex closer to the middle of the screen so you can begin working with it. To do this you'll need to select it, then press the G-key to "Grab" it. Once you press the G-key the vertex will move to follow the movements of your mouse, just like an entire object would in Object Mode. Move the vertex near the center of the screen and press the LMB to place the vertex and confirm the translation. Of course, the keyboard constraints that you learned in the Object chapter also apply here: hitting the X, Y or Z-keys will constrain vertex movement to that axis. Pressing them twice uses the alternative transformation space as defined on the 3D header. Tip: Transform keys in Edit Mode carry over from Object Mode: G-key (Grab), S-key (Scale), and R-key (Rotate), as well as axis constraint shortcuts, transformation manipulators and mouse gestures. Exact Positioning Using the G-key is a great way to move things as long as you don't need to be precise. In fact, most of your modeling will be done using this method. However, there are times when you'll need exact positioning. To achieve that kind of precision in Blender you'll use the "Transform Properties" panel. To access the transform properties dialog make sure you have something selected (the remaining vertex in this case) and press the N-key.
  11. Fig. 4: The Transform Properties panel. In the Transform Properties panel you'll see that you have a number of different options. Here you can rename your object by modifying the text in the "OB:" text field (the object in the example is named "Cube"), or place the object exactly where you want it by modifying the numbers in the various X, Y and Z text fields. To place the vertex in the exact center of the 3D workspace hold the Shift-key and click the LMB in the "Vertex X:" spinner control. This makes the field instantly editable. Type the number "0" and press Enter. To complete the process, repeat these steps for the "Vertex Y:" and "Vertex Z:" fields. For faster access to the Y and Z controls, you can simply hit the Tab key when you've entered your value in the X control. When entering values into fields in Blender, the Tab key functions much like it does in other programs you might be familiar with, taking you to the next text field. Tip: N-key brings up the transform properties panel for numeric positioning.
  12. The Extrude Tool A vertex by itself will not show up in a render. So what can we do with vertices? Combine them into edges (which still don't show up in a render) and then into faces. Faces render. There are several ways to create edges from a vertex. The easiest way is to extrude the vertex. Extrusion is simply taking one thing, like a circle, and extending it into space. Extruding a circle into space creates a cylinder. Extruding a square creates a box. Extruding a vertex in Blender will create another vertex and an edge that links them. To do this, make sure the vertex is selected and press the E-key. Now move the mouse around and you'll notice that you are moving another vertex, and that an edge attaches the two vertices like a string. To place the new vertex where you want, press the LMB. To add some precision to your placement you can hold the Ctrl-key while moving the vertex and it will "Snap to" the nearest increment in Blender units. Of course, you could also use the Transform properties dialog. Tip: E-key extrudes vertices, edges and faces in space. If you need to create a whole chain of vertices, there is a simpler workflow than using the E- key for extrude. With a vertex selected, clicking with Ctrl-LMB in the 3D view creates a new vertex at the location of the click, selects it and links it with an edge to the original vertex. By holding down the Ctrl key and LMB clicking repeatedly, you can quickly build a chain of vertices linked by edges. This fast extrusion feature will actually work with any mesh selection: vertices, edges or faces. Tip: Ctrl-LMB will automatically extrude the current selection to the point of the mouse click. Another easy way to create an edge is to duplicate a vertex by selecting a vertex and pressing Shift-D. After using the LMB to place the duplicated vertex, Shift-RMB selecting the original and pressing the F-key will create an edge between them. Removing Extra Vertices There are many cases where you may end up with vertices that occupy nearly the same space. You may have imported a mesh model from a CAD program that has portions of the mesh duplicated in the same spot as the original. You may be trying to join two parts of a mesh into one, scaling vertices toward each other until they occupy the same point. In any of those cases, you need to remove the extra vertices and join the edges and faces that they help to define. To remove extra vertices and join the edges and faces that they build, select the vertices in question and press the W-key, choosing "Remove Doubles" from the popup menu that appears. Remove Doubles works with a distance threshold value, adjustable in the Mesh
  13. Tools panel of the Edit buttons (F9) with the Limit spinner, so you can, for example, select all vertices in the entire mesh and use the function without fear that it will remove all but one of your vertices. In the illustrations, you see two halves of a cube, separated, then with the vertices scaled together. Figure PMD.045.1, .2: [no text] Although the vertices occupy the same space, the edges and faces they build are not connected, and will render with ugly lines at the gaps. As you can see in the next illustration, the vertices are still independent, and can be selected and moved apart from each other.
  14. Figure PMD.045.3 Once the vertices of the cube have been selected and the Remove Doubles function has been used, the vertices are merged into one, and the edges and faces they build are now truly connected.
  15. Figure PMD.045.4: With the vertices joined into one, the two halves are now one continuous mesh. Tip: Remove Doubles, from the W-key specials menu and Mesh Tools buttons, merges vertices that are very close together. A common technique is also highlighted in the next example. When trying to get vertices close together for a merge, it is often easier to use the Scale command (S-key), scaling them down to 0 with the help of the Ctrl key, than it is to move one (G-key) and trying to line it up with the other on screen.
  16. Fig. 5 Working with an Edge With edges, the same rules and methods that you have learned with vertices apply, plus more. You might be wondering why working with an edge (or face) is important since you already know how to work with vertices. By being able to work with all three, you will be able to take full advantage of Blender's tool set and learn to work as efficiently as possible. Selecting Blender has tools made just for selecting edges. To activate Edge select mode, click the icon on the 3D header that looks like a diagonal line. It's between the Vertex select (four dots) and Face select (triangle) icons. Once Edge select is activated, you'll be able to RMB click anywhere along the edge to select it. To select multiple edges, you can hold the Shift key while RMB clicking on other edges. Fig. 6
  17. Blender also has tools for selecting multiple edges. Under the Select menu on the 3D header, you'll see the Edge ring and Edge loop options. These can be used to easily select complex groups of interrelated edges, and are especially useful when working with character models. In the case of this head model, Alt-RMB selects the loop of edges that runs around the mouth, giving the modeler easy access to this crucial area. Also, Ctrl-Alt-RMB will select the corresponding ring of edges, in case the modeler would want to cut a new loop of edges through them to add, say, a crease to the face. Figure PMD.07.1: Edge loop selected around the mouth.
  18. Figure PMD.07.2: Edge ring selected around the mouth. Tip: Alt-RMB selects an Edge Loop; Ctrl-Alt-RMB selects an Edge Ring. Working with Faces Creating a Face Faces are created with a selection and the F-key. To create a face, you need to have either three or four vertices selected (three will build a triangle face, four will build a quad face), or two edges.
  19. Figure PMD.08: Pressing the F-key to create a triangle face and quad face from vertices, and a quad face from two edges. Tip: F-key creates a face from three or four selected vertices or two selected edges. Selecting As with anything else in Blender, the quickest way to select faces is to switch over to Face Select mode and use the RMB. The Face Select mode button is to the right of the Edge Select mode button on the 3D header and has a triangle as its icon. Another way to change select modes is by pressing the Ctrl-Tab keys. You'll get a menu that allows you to choose your select mode without having to use the icons. Adding Detail to a Mesh If you are constructing a model and you find that you need more detail in a certain area, one way to achieve this is to "subdivide" the face (or faces) that you are working with. Subdivision cuts a face into four new faces that take up the same space as the previous single one did. To subdivide a face, make sure you have one selected, then click the Subdivide button on the Mesh Tools panel in the Edit buttons. Subdivide can also be found in the Specials menu by pressing the W-key.
  20. Figure PMD.09.1: A triangle and quad face, before and after subdivision. You'll see that there are some other subdivision options in the Specials menu. The "Subdivide Multi" option allows you to perform more than a single slice at once on the selected faces, and is quicker than selecting "Subdivide" many times in a row. "Subdivide Multi Fractal" does basically the same thing, but moves the resulting extra vertices around randomly. It's great for creating terrain, or any surface that needs to have a rough, random mesh. Immediately below that on the menu is "Subdivide Smooth", which will not only subdivide the selected portions of a mesh, but will simultaneously attempt to smooth out all edges created by the process.
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