by Kenneth Styrberg
Relevant to Blender v2.34
In many real life situations - like skin or metals - the color of diffuse and specular reflections can differ slightly, based on the amount of energy a surface receives or on the light angle of incidence.
Ramp Shader options in Blender now you allow to
set a range of colors for a
Material, and define how the
range will vary over a surface, and how it blends with the 'actual color'
(typically from material or as output of texture).
Since texture calculations in Blender happen before shading, the
Ramp Shader can completely replace texture or material
color. But by use of the mixing options and Alpha values it is possible to
create an additional layer of shading in Blender materials.
Ramps panel is located in the
Material context (F5). Here you can use the
top two buttons to show either settings by pressing Show Col
Ramp for diffuse or Show Spec Ramp for specular
ramps. (Figure 10.15, “Ramps Panel.”).
Pressing the button Colorband enables
Shaders. By default it opens with 2 colors, with the first having
Alpha = 0, and no color. And the second having
Alpha = 1 and a cyan color. (Figure 10.16, “Ramps Panel Colorband.”).
Add - Adds a new color in the middle of the colorband with neutral grey as default color.
Cur - Displays the current selected color number on the colorband.
Del - Deletes the current position.
E/L/S - Defines the type of interpolation between the
Ramp Shader color and the
E - Ease or Qubic, L - Linear and
S - B-Spline.
Alpha - Defines how much of the
Shader effect will be seen. An
Alpha value of
0 means that the
Ramp Shader is totally
transparent and will not be seen in the final material. A value of
1 sets the
Ramp Shader opaque. If you
defined colors with different
Alpha values, they will be
interpolated between each other to get a smooth transition between different
transparency settings. You can preview the
Alpha settings on
the color band with the checker board pattern behind the colorband. If pattern
is visible then the transparency is less than 1.
R/G/B - The current color RGB values. You can
LMB on the color field under the
to choose a color using the
The current color is marked with a slightly thicker bar in the colorband. To
select a color position you can either press LMB on the
desired color position, or step the current color number up and down with the
right and left arrows in the
Cur field. You can also
SHIFT-LMB in the field and enter the required color number
You can move the position of a color by simply pressing the
LMB and dragging over the colorband. There is also a
Pos field where you can move the position with the left and
right arrows or SHIFT-LMB in the field and enter the position
If you reorder the positions of the colors, they will be renumbered so that they always start with 0 from the left and increment to the right.
The two pop-up buttons and the value slider in the bottom of the panel
defines how the
Ramp Shaders work:
Shader - The value as delivered by the basic shading formula (like Lambert or Phong) defines the color. Here the amount of light doesn't matter for color, only the direction of the light.
Energy - As
Shader, but now also lamp
energy, color and distance, is taken into account. This makes the material
change color when more light shines on it.
Normal - The surface normal, relative to camera, is used
Ramp Shader. This is possible with a texture as
well, but added for convenience.
Result - All three previous options work per lamp, this
option only does it in the end of all shading calculation. This allows full
control over the entire shading, including 'Toon' style results. Using alpha
values here is most useful for tweaking a finishing touch to a
Method menu has several options for blending type:
Mix, Add, Subtract, Multiply, Screen, Divide, Difference,
Darken and Lighten.
Method options gives an option to choose how the blending
between the color from
Input and the
Shader will be done.
Factor slider denotes the overall factor of the
Ramp Shader effect: 0 means no effect and
1.0 means full effect.
Let us make a simple example using
1. Remove default cube object from scene and add
a Monkey mesh! (SHIFT-A -> Add -> Mesh -> Monkey).
Press Subsurf and set display and render
Subdivision level to 2. Press Set
Smooth to get a nice smooth Monkey! All this in
Edit context. (F9).
2. Now press TAB to exit
EditMode. Press F5 to enter
Material context. In the
press Add New to add a new material! Change the parameters in
Shaders tab as Figure 10.20, “Shader settings.”.
3. Press Ramps tab to open the
Ramp Shader panel. Press Colorband to
Ramp Shader effect. Now try to set the
parameters as Figure 10.21, “Ramp Shader settings.”. Remember to set the
Input to Normal. The second color to the
right is set to
Alpha = 0 and the color to
Here is the rendered result of the settings we just entered above. In
Figure 10.24, “No Ramp Shader.” there is no
active. In Figure 10.25, “Color Ramp.” the
Ramp is activated and finally in Figure 10.26, “Both Color and Specular Ramp.”
Color Ramp and
Specular Ramp are
Remember here we have just demonstrated one effect of the
Shader. There is much more to explore, try changing the
Method parameters, to see
totally different results from the ones we have just seen in this example.