Thanks for that write up, Im just got a really good result using that method. It'll certainly be a mix of geo and fog.
Really appreciate it, Cheers. On Mon, May 4, 2015 at 6:12 PM, Matt Lind <[email protected]> wrote: > Many ways to attempt this. > > If you prefer working with geometry, you can create some curves and > extrude them vertically along an axis to create a wall of sorts, then > animate the curves wriggling as they travel across the sky. The extruded > surface can use a shader to control falloff. Render the geometry as > separate passes using constant shading for faster render times as well as > full control over the color. Finally, blur the passes in post before > assembling. > > Another route to consider is using a light, 2 bitmap textures, and a cube > with a volume shader. Essentially you'll shine a light onto the textures > which act as a mask to create light rays inside the volume of the cube. > The rays can be rendered, colored, varied and blurred. > > The cube is made large enough to fill the sky and uses a constant material > with full transparency so the inside of the cube can be seen. The first > bitmap texture is a matte containing the noise pattern you want to use for > the shape of the borealis effect. The 2nd bitmap texture is a > wash/gradient to drive the effect's color. Project the textures in the XZ > plane from underneath onto the cube. Shine the light from underneath the > cube to cast rays into the cube via the volume shader. The volume shader > can have most of it's features deactivated to speed up rendering (should > render really fast). All you need is the active light list, density, and > color....and possibly raymarching step set small enough to not see > aliasing. You should not need shadow casting provided by the volume > shader. Shadow falloff of the light as well as density of the volume > shader control the height of the borealis effect, which can also be varied > by inserting a noise node into the rendertree, or by projecting another > texture from the light or onto the side of the cube to act like a matte. > render the scene, then blur the results a bit in a compositor. The > advantage to this technique is it can be completely procedural, but still > leave the door wide open for you to override that with manual control at > any step of the way. > > Matt > > > > > > > Date: Mon, 4 May 2015 11:47:45 -0400 > From: Will Sharkey <[email protected]> > Subject: aurora borealis effect > To: "[email protected]" > > > I've been doing some research on how to achieve this effect with particles. > I was thinking sheets of particles with a bunch of turbulence and other > forces: > > https://youtu.be/8NrhuBhgmjU?t=33 > > I'm still brainstorming, Any thoughts or approaches? Would you use > particles or animated Geo and a bunch of layered animated sequences? > > Thanks in advance > >
