Could anyone give me a clue as to how that glowing, light emitting particle effect is done?
Like in the HTC radar advert and lots of abstract demos.
thanks
jb
You want the particles to glow? Or you want a blooming in the lens / camera?
I think it’s particles emitting light. There’s quite a lot of it in people’s demos, but I can’t figure it out ( just started with krak)
I take it it’s something to do with the emission channel, maybe a gradient driven by the age and lifespan of the particles in magmaflow. It looks like they are casting light onto the rest of the particles in the HTC radar ad.
There are several things that can be done to make particles glow.
If you watch the Matthias Mueller videos on YouTube, he usually renders volumetric particles with an Omni light put inside the cloud and set to a realistic Decay.
youtube.com/watch?v=7c4WYzr30B0
As you mentioned, it would be possible to set the Emission of the particles via MagmaFlow. But I don’t think anyone is doing that directly. Also, in the current builds of Krakatoa, Emission does not affect neighbor particles, it just provides an additional color that is not affected by lighting. That’s usually the effect of the Light approach mentioned above.
The third approach is to render the particles as Additive (or partially additive). There are two ways to get there - the >Force Additive Mode option in the Main Controls makes ALL particles in the scene additive by setting their Emission to the Color and the Color and Absorption to black. The result is that particles drawn into the same pixel add their colors, resulting in a glowing effect where the concentration of particles is high: thinkboxsoftware.com/krak-ba … _Rendering
The second way is to set the Color, Emission and Absorption channels directly per particle using Magma or Materials/Maps. This allows you to mix volumetric shading and additive shading - see here: thinkboxsoftware.com/krak-mi … and-volum/
thanks, that’s pointed me in the right direction
jb
Though you can’t do sampling with the current KCM’s, you can do it with particles. So you could make your basic particle animation, light it, save out the PRT’s with emission, then resample and diffuse that emission data over the neighboring particles. Since it’s history independent, it’s not as bad as it sounds. 
Hm, I thought you can’t do things like sample the particles around the ‘current’ one and get values from them?
AFAIK it is not possible in Krakatoa 1.x.
Krakatoa MX 2 can do that between two systems. It cannot sample within the same system yet.
You can with with Box#3 or TP at least. The workflow for Box#3 isn’t that bad.
Having sampling in Krakatoa 2.x will help, but you lose some controls compared to Box#3. Multithreading helps, of course.