I’ve found a great tutorial on creating snow (https://www.youtube.com/watch?v=G9vKSqRzhGQ) but I’d like to replace the snow flakes with sparkly particles that resemble twinkling bright stars. Is there an easy way to create a twinkling particle and replace the snow particles with it?
I am guessing it’s only a matter of creating the material, but I was wanting something even more dynamic than just a material image of a star or spark. I’d like the particles to actually sparkle.
Sorry to say, but that tutorial is awful.
1 - You NEED particle color to at least multiply the alpha of that with the opacity for particles so they fade in and out. Otherwise, particles will pop in and out of the scene.
2 - You don’t need to generate a mask for both the color and opacity: this will generate a dark outline around the edge of the particles. I typically keep the color a clean color and use a radial mask on the opacity only.
3 - I always use, at the very least, volumetric non-directional lighting for particles. If you don’t, then your snow scene can take place at night and all the snow appears as garish bright white dots. I plug color info into base color rather than emissive to make sure snow is not literally emitting light. Most of the times I’ll use a proper normal map to get better lighting information, but it depends on the fidelity of what you’re trying to achieve.
4 - Initial size is huge. 25x25 isn’t snow, it’s raining soccer balls. I made my snow size X:6,2 Y:8,6, using the PSA_Velocity screen alignment so you get a nice stretch of the particle in the direction it’s going… even this is too large, but any smaller and you’d barely be able to see the effect at a distance, even at 1080p.
5 - If you only use initial velocity to generate direction, the snow will fall as a straight line from the sky. Sure, they’re going at different angles, but there is no wind. Think about how leaves fall to the ground: they don’t fall in straight lines, they curve in arcs. In the real world, there is wind and air resistance tumbling light objects as they fall, and you can use the Orbit module to simulate this fairly easily.
If you want snow to sparkle, this can be done a number of ways. Unfortunately GPU sprites don’t give you very many options: you can’t access much information dynamically. Each particle has its own alpha, so you can use Color Over Life and the curve editor to fade the particle in and out, but this can be tedious to set up and add a lot of unnecessary information. I did this through a hacky technique: I used the particle position node added with time to feed into a sine wave: the sine wave will fade the particle in and out, and the position of the particle in space will offset the sparkling. Of course this means if a particle travels faster or in certain directions it will flash faster, but together with the more complex movement of the particles, you won’t notice it as really being a problem. I’ll make sure to post footage, or make a tutorial, when I get the chance!
Mariomguy, I look forward to your tutorial. And thank you for your reply!
No problem! It will take some time for me to record a decent tutorial, so here’s a screenshot for you.
I understand this concept, but how do you feed the particle position node into a sine wave?
