Color Path Editor


The Color Path Editor's main purpose in Particle Storm is to work with the particle shader. The particle shader exists as a controller, and with it you can define how particles are to appear when they are rendered for final output. The Color Path Editor's interface is similar to the Envelope editor, except for the following controls:

  • ColorPath Gradient: This bar displays the gradients of colors you specify as well as the Alpha Channel values. (see image below)

    • By clicking on the small area just above the gradient bar you can create color keys.
    • By clicking on the small area just below the gradient bar, you can create alpha keys.
    • Left clicking and dragging the mouse over any key will move the key.
    • Left clicking over any key will select the key.
    • Pressing Delete on the keypad when a key is selected will delete the key.


    HOW TIME RELATES TO THE COLOR PATH

    Since we want to be able to specify what color a particle is at a specific time, the Color Path Editor's range is a time unit. Therefore, we can create particles that change color over time. The current time is displayed in the "Current" edit box.

  • HLS/RGB: These are different methods of selecting colors. You can drag the mouse over the color swatch to select what color you want or numerically type it in.


    • NOTE: The edit box titled "A" represents the alpha channel. In other words, it allows you to specify how transparent a particle is at some point in time.

    STANDARD ENVELOPE FUNCTIONS AND HOW THEY RELATE TO THE COLOR PATH EDITOR

  • TCB: Tension, Continuity, and Bias are adjusted just like the Envelope editor. However, in the context of the Color Path, altering TCB will allow you to have control over the ramping of color values.


  • End Behaviors: These behave in the same way as in the Envelope editor. In the Color Path editor this can be a very powerful feature used to easily create shimmering particles.



    • Let's change the color of particles over time using the Color Path Editor.
      1) If you haven't already done so, clear the project.
      2) Hit the Play button. Notice that there are moving particles in the preview window.
      3) Right click on "Controllers". A popup will appear with all the available controllers.
      4) Select "Shader" from the list. An instance of a particle shader has been created and added to the Controller tree.
      5) Now Click on "Shader" under the controller tree. The parameters will appear.
      6) Note that all particles now appear black. This is the default color the shader assigns for all particles.
      7) Click on "Edit Color". This will bring up the Color Path editor.
      8) Create a color key anywhere along the color bar (remember to mouse click on the upper slit of the colorbar to create color keys).
      9) Now select a color by clicking and dragging the mouse around in the color swatch. You will notice that the color bar is changing colors. Also the particles in the preview window are changing colors in real time as well.
      10) Now create another color key anywhere along the color bar. Select a different color for that key. Notice that there is a nice ramp between the first color and the second color.
      11) You may or may not notice the particles changing colors depending on your timing settings. If so, click on "Drag" and drag the keys around. Notice that the "Current" time value changes. As you drag the color keys around, you should notice the particles changing colors in the preview window.



      Changing the transparency of a particle over time.

        1) Keeping the above color settings, create an alpha channel key.
        2) Now create another alpha channel key a bit further down than the previous key.
        3) Drag the slider by the "A" edit box. Notice that the color gradient slowly become transparent and the background checkers show through. Similarly, the particles in the preview window also slowly fade away.
        4) Just like we did in the previous tutorial, you can drag the alpha channel keys to adjust timing.
        5) For an interesting effect, set the end behavior to Ping-Pong. You can use the zoom feature to see the effect repeating.