Blender Documentation: Last modified September 29 2003 S68 | ||
---|---|---|
<<< Previous | Materials and textures | Next >>> |
Blender provides a set of materials which does not obey to the shader paradigm and which are applied on a per-vertex rather than per-face basis.
If you press the Halo button in the materials (F5) buttons the Material Buttons changes as in Figure 42.
The Mesh faces are now not rendered anymore, instead at each vertex a 'halo' is rendered. This is most usefull for particle systems, which actually generate free vertices, but can also be very handy in many situations, for creating some special effects, to make an object glow, or to make a viewable light source.
The three colors are now relative to the colour of the halo itself, and of any possible ring or line you might want to add with the relevant toggle buttons in Figure 42.
Figure 43 shows some results on a single vertex mesh. The halo size, alpha and hardness can be adjusted with the sliders bottom left in Figure 42. THe Add sliders determines how much the Halo colours are 'added to' the colours of the objects behind and toghether with other halos.
It is possible so set the number of rings, lines and star points independently with the num buttons Rings:, Lines: and Star:. Being these features random, the Seed: NumButton sets the generator seed.
Now we will try to use a halomaterial to make a dotmatrix display.
Add a grid with the dimensions 32x16. Add a camera and adjust your scene in such a way that you have a nice view of our billboard. Now use a 2D image program to create some red text on a black background, and use a simple and bold font. Figure 44. is an image 512 pixels in width by 64 pixels in height, with some black space at both sides.
Now add a material for the billboard, and set it to the type Halo. Set the HaloSize to 0.06 and render, you will see a grid of white spots. Now switch to the TextureButtons and add a new image texture. Load your picture and render again, you will see some red tinted dots in the grid. Go back to the MaterialButtons and adjust the sizeX parameter to about 0.5 and do a render again, the text should now be centered on the Billboard.
To get rid of the white dots, adjust the material color to a dark red and render again. We have now only red dots, but it is still too dark. We can fix this by entering EditMode for the board and by copying all vertices unsing the SHIFT-D shortcut. We can now adjust the brightness with the Add value in the MaterialButtons.
You can now animate the texture to move over the billboard, with the ofsX value in the MaterialButtons. Of course, you can also use a higher resolution for the grid, but then you will have to adjust the size of the halos (Figure 45).
![]() | Halo Texturing |
---|---|
By default Textures are applied to the Object with Object coordinates and reflects on the halos general properties. To have the texture take effet within the halo press the HaloTex button. This option will map the whole texture to every halo. This is very usefull when you want to create a realistic rain effect using particle systems, or similar. |
Our eyes have been trained to believe an image if it shows familiar artifacts from the mechanical process of photography. Motion blur, Depth of Field and lens flares are just three examples of these artifacts. The first two will be analized in the the Chapter called Rendering, the latter can be made with special halos.
A simulated lens flare tells the viewer that the image was created with a camera, and it is therefore `authentic'.
In Blender, a lens flares is created from a mesh object using the Halo button and then the Flare options in the material settings. Try turning on Rings and Lines, though I would recommend that you keep the colors for these settings fairly subtle. Play with the Flares: number and Fl.seed: settings until you arrive at something that is pleasing to the eye. You might need to play with FlareBoost: for a stronger effect (Figure 46). This tool does not simulate the physics of photons traveling through a glass lens; it's just a eye candy.
Blender's lens flare looks nice in motion, and disappears when another object occludes the flare mesh. (Figure 47).
<<< Previous | Home | Next >>> |
Multiple Materials | Up | Environment Maps |