[WML-Source: CurveSurface_cw.wml][TOC][Part00]

[chapter]Modelling

[section]Curves and Surfaces

[subsection]Curves

Blender offers two basic types of Curves:

[subsection]A Logo with Curves

Start a new scene scene or load "BlenderLogo00.blend" from the CD. You will get a frontview onto a loaded Blender-Logo as Backgroundpicture. The tracing of a picture in a 3D-application is often referred as Rotoscoping. The scene also contains a setup for a camera, light and a background on layer one.

  [images/CurveLogo_ViewButtons.tga]

The loading of an background image is done via the ViewButtons SHIFT-F7 . Move your mouse over the 3DWindow and press SHIFT-F7 . Here click on the button "BackGroundPic", then on "LOAD" to load a picture via the normal ImageSelect. With the "Size:" parameter you can adjust the size of the picture, the "Blend:" slider changes the transparency of the picture. With the MenuButton left of the "LOAD" button you can switch between all loaded pictures.

Return to the 3DWindow with SHIFT-F5 . Add a Bezier-Circle in the front view to form the inner blue spot of the Blender-Logo. Scale the circle so that it matches with the oval shape of the inner part. When you switch the camera-view to solid mode ZKEY , you will see a filled circle.

Without leaving the EditMode (TAB ) add a new "Bezier Circle" with SHIFT-A . Tweak it until it fits with the inner orange part of the logo. Leave the EditMode now and in the shaded camera view we see that Blender automatically fills curves and calculates the holes which may occour. In this case it is obviously not what we want, but this will change when we complete the logo.

  [images/CurveLogo01.tga]

The next step will be to add a new Bezier-Circle for the outer border of the logo. We will have to open the circle (try it with CKEY , hit this key again to close, at least one vertex of the curve has to be selected) and it will open to the lower left but we need it at the upper left to add the "fingers" of the logo. The simples solution is in this case is to rotate the circle 90 degrees to the right (press CTRL to activate the rotation snap).
If you leave the EditMode and reenter it, all selections are gone, to select a complete curve move the mousepointer over one vertex of a curve and press LKEY
For this part of the logo we will have to adjust the curves with their handles.

[point]Bezier-Curve handles

A curvepoint consists out of three handles. The middle handle is used to move the entire vertex, selecting it will also select the other two handles, allowing to move the complete vertex. Selecting one or two of the other handles will allow you to change the shape of the curve by dragging the handles.

There are four types of handles:

  [images/BezierHandles.tga]

Handles can be moved by first selecting the middle vertex with the RightMouse; this also selects the other two vertices. Now start Grab mode with RightMouse-hold-move. Handles can be rotated by selecting the end of one of the vertices; again, use the Grabber with RightMouse-hold-move. As soon as the handles are rotated the type is modified automatically:

A separate resolution can be set for each Bezier curve - the number of points generated between two points in the curve.

Back to our logo! Make the left vertex a "Vector Handle" by selecting it and press VKEY . Then move the vertices in a way that they match the logo.

  [images/CurveLogo02.tga]

Now we have to make new vertices to form the fingers. We will first trace them roughly and make the adjustments later. Select the left Handle from the opened curve. Now click with the left mousebutton while holding CTRL on the left finger where the curve changes from straight to curved. A new vertex is created, notice that it is also of the type "Vector Handle". Now add a new vertex to the opposite side of the finger, we will add the roundings later.
Add new vertices by holding CTRL and clicking with the left mousebutton. Blender will automaticly generate new edges.

  [images/CurveLogo03.tga]

Now trace the rest of the logo this way and close it with CKEY at the end. In the shaded view you now get the first impression of the filled logo, of course we have to edit the roundings at the fingers.

Enter EditMode TAB and select one of the handles pointing inside at the end of one "finger" and grab it until it fits the rounding of the finger. Do the same with all other fingers. Zoom into your view to get a closer look. At this time you can also adjust the other vertices to match the logo perfectly.

We now have a nice but flat logo which you can render (Switch on Layer one SHIFT-1 for a camera and light setup in the scene from CD).

[point]Adding depth to the logo

Select the logo and go to the EditButtons F9 . Here you can add depth with adjusting the "Ext1:" parameter. With the "Ext2:" parameter you get nice round edges, this is called Beveling. You can control the subdivision of the beveling with "BevRsol:". If your curves did not appear smooth enough increase DefResolU: and press "Set". I choosed a resolution of 30.

  [images/CurveLogo04_Ext.tga]

[point]Adding a material to the logo

Select the logo and go to the MaterialButtons F5 . Add a new Material with the ManuButton and make it orange, the RGB values are : R:1.000 G:0.427 B:0.169. Now your whole logo will be orange, we need to use multi materials to color the blue circle in the center of the logo.

Enter EditMode and select the middle circle with LKEY while your mousepointer is over one vertex of the curve. Now go to the EditButtons F9 and klick here on "New" in the material settings. The button under "Material" will now show "2 Mat: 2" which means two materials, material nr. two is active. We can now apply the secon materialindex to our middle circle with clicking on "Assign".

  [images/CurveLogo07_MultiMat.tga]

So far we only have made two material-indices, but both pointing to the same material. Leave EditMode and switch to the MaterialButtons again. In the Header of the MaterialButtons you will see that the name of the material is blue, the button right from the name is displaying "2", which means the material is used twice. Now click on the "2" Button and answer the popup-menu positively. Rename the material to "Blue" and change the color to R:0.000 G:0.333 B:0.443. Press ENTER on the keypad to redraw the shaded 3DWindow, and the change in color will show up.

  [images/CurveLogo07_MultiMat01.tga]

Now you can render the completed logo.

  [images/CurveLogo.tga]

[subsection]Surfaces

(No idea...Vase, Cannon-cw-)

  [images/CurveSurface/AddSurface.tga]

[subsection]Text

  [images/Text/TextSamples.tga]

Text is a special curve type for Blender. Only Postscript Type 1 fonts are supported by Blender.

Start with a fresh scene by pressing CTRL-X and add a Textobject with the Toolbox (ADD->Text). In EditMode you can edit the text with the keyboard, a textcursor shows your actual position in the text. When you leave the EditMode with TAB Blender fills the text-curve, so that you have a flat filled object, that is renderable at once.

Now go to the EditButtons F9 .

  [images/Text/TextEditMode.tga]

The buttons are described in detail in the reference section. As you can see in the MenuButton Blender uses by default his ".Bfont" when creating a new textobject. Now click "Load Font" and browse with appearing the Filwindow to a directory containing Postscript Type 1 fonts and load a new font (there are several free Postscript fonts provided on the CD-ROM coming with this book). Try some other fonts. After loading a font you can use the MenuButton to switch the font for a textobject.

Fo now we have only a flat object. To add some depth we can use the "Ext1:" and "Ext2:" buttons just the same way we have done this with curves.

With the "TextOnCurve:" option you can make the text follow a 2D-curve. Use the alignment buttons above the "TextOnCurve:" textfield to align the text on the curve.

A powerfull function is that a Textobject can be converted with ALT-C to a curve-object, which allows you to edit the shape of every character. This is especially handy for creating logos or custom lettering.


-cw- Last modified: Tue Oct 17 14:05:27 CEST 2000