Velocity Color Tracers

A Fun Tutorial Blending Physics and Color:

In this project we learn how to make a movable ball leave behind a trail of tracer balls, each a color representing the movable ball's speed at that point in space / time.

Video Tutorial on How to Build "Velocity Color Tracers"

<h4> </h4> <h3>What you'll learn:</h3> <ul> <li><strong>Physics</strong>: <ul> <li>Working with Speed via script: Linear velocity magnitude </li> <li>Components of velocity: velocity in the Y direction </li> </ul> </li> <li><strong>Emitters</strong>: <ul> <li>"Moving": emit my sample object when the emitter moves.</li> <li>"Clone as 'copy' ": clone the item I emit as a full copy with its own set of properties, not sharing properties with the source of the clone. </li> <li>onEmit() event / function: The onEmit() function happens right before the emitter emits the objectd and gives you a chance to change properties on the emitted object. </li> </ul> </li> <li><strong>Color</strong>: <ul> <li>Hue Saturation Brightness. </li> <li>How to use hsb() to set color in script</li> </ul> </li> <li><strong>Scripting</strong>: <ul> <li>Working with linear velocity.</li> <li>Working with hue saturation and brightness for changing color in script.</li> <li>Print statement.</li> </ul> </li> <li><strong>Movable Ball Actor: </strong> <ul> <li>Setting properties to give the ball more power and change maximum speed. </li> </ul> </li> <li><strong>Basic Construction:</strong> <ul> <li>Basic object hierarchy work</li> </ul> </li> </ul> <hr class="style14" /> <h4> </h4> <h4><strong>Script Used in this Tutorial:</strong></h4> <pre class="prettyprint lang-lua linenums">function NodeEmitter:onEmit(obj) vel = self:getParentNode():getRigidBody():getLinearVelocity():length() --print(tostring(vel)) obj.color = hsb( ( 180 + (vel*10)) ,1,1) end</pre>

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A Fun Tutorial Blending Physics and Color:

Video Tutorial on How to Build "Velocity Color Tracers"

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