The color animates to super-bright (greater than 1.0) for the first half of the lifespan, while the alpha ramps from black to white, then gradually falls back off to black.
If you open the P_Waterfall Particle System in Cascade, take special note of the Scale Color/Life module. If you check out the Material (named M_WaterDrop_SubUV), you can see the Particle Color node driving these values as described. This means that the Green channel is driving all RGB data for color, which gives a grayscale result. Red - Drives refractive index of the water, or how much it bends light. Since the water does not need to actually change color (water is colorless, after all), we use the Particle Color data in the following manner: Here, however, we are using that Red, Green, Blue, and Alpha (RGBA) data to drive a few more things. Typically, this node allows us to change the color of the particles as they fall, by animating their color and alpha values across their lifespan. Because of this, we have employed some trickery, using a Particle Color node within the Material. It is important to keep in mind that GPU Sprite particles do not support Dynamic Parameters, which are typically used to send data from a Particle System into a Material. This uses the Scene Depth G-Buffer to calculate collision surfaces and incurs only a minimal performance cost. This is done using a Collision (Scene Depth) operator, which is only available to GPU Sprites. The two techniques could be combined, however, for further variation within the effect.Īs the water falls down the rock face, you will notice it splashing and colliding with the surface. Using this method, we can get much more complex and interactive behavior than we would if we created the effect using Materials and Static Meshes alone. However, since they are GPU Sprites, the actual simulation (tick) cost is very low, since that is passed off to the GPU. Of particular importance in this effect is that camera alignment plays a significant role the player is not intended to walk right up to the water, but rather to view it from a small distance.īecause these particles are using a translucent Material, they do come with an overdraw cost - meaning that many drops will have to render on top of one another. The Waterfall effect combines multiple Materials and Particle System settings to simulate the effect of water cascading down a rock formation. You are encouraged to open these up in Cascade to see how each effect was assembled.įor more information on Cascade and Particle Systems, please see the Particle Systems documentation.Ĭontent Browser Location: Game/Effects/Particles/Water/P_WaterFall
The following Particle Systems are the water effects that were created for this example.