Making Particles Sparkle???

[pluMmet]

http://www.neilblevins.com/cg_education/sparkling_snow/sparkling_snow.htm

should help...for sparkiling anyway...you got the right idea about the dissipering. Just put an .avi in the opacity channel.

[Johnny_Scott]

use super spray, triangle particles, set their self illumination to 100 % and use a falloff map to vary opacity such that the particles dissappear at any angle relative the view > than about 30 degrees (the falloff curve describes face normal angle relative the camera by default). Goto spin/rotation and be sure this is randomized; also set the spin time low, and put some variation in there.

You'll also probably want to use a falloff map to vary the diffuse color so that particles slightly facing away from the camera but still visible will appear a slightly different color than when facing directly at the camera. I use a gold color for facing slightly away and pure white for directly facing the camera (this looks like classic gold pixie dust when rendered).

Now as the particles spin, they will suddenly appear as they face the camera, and quickly fall off as they receide away from the camera (thanks to the falloff opacity map), because you set the spin time yourself under the superspray particle rotation/collision sub-panel, you can control the rate of sparkle with a lot more accuracy and control than using an actual animated image map to vary opacity which you'll have to rerender and modify each time you want to tweak the speed of sparkle; this way you can decide if your particles slowly sparkle, or sparkle really fast and it's as easy as switching the spin time number.

To me, this method of simulating sparkling particles is a realistic method because in real life particles sparkle because they hit their highest level of brightness at a specific angle as they spin and fall, cycling between being invisible (because they are usually too small to show up underlit) and being really bright. This method replicates this effect in quite a similar fashion to reality.

What's more, it doesn't take a lot of particles to do this trick and it looks even better rendered WITHOUT antialiasing (use small particle size) so rendering is very fast.

To enhance the effect, add a small amount of glow or blur in post production with photoshop's batch features, an actual video comp tool, or use max's native glow filter via video post.

If you'd like, I can post an example avi if necessary.

sorry about the wordiness! :shrug:

[Mr Fudge]

Yeah, I would really appreciate it if you post a little sample.

I'm keen to see what it looks like rendered.

Great idea about switching off anti aliasing. I hadn't thought of that. Also good for retaining the brightness of smaller particles.

Caio,
K

[Johnny_Scott]

Here's a simple example using the techniques fore-described.
http://home.att.net/~johnny.w.scott/ba.avi
and if you need it, the max file
http://home.att.net/~johnny.w.scott/s02.max

The avi has no effects or filters added but you'd probably want to take the raw, aliased particles and add a faint glow effect, render them as a tif sequence separate from what will lay behind them, and comp them in.

The rate of sparkle is tweaked with the spin time param under the particle rotation/collision rollout.

[Johnny_Scott]

MR Fudge- Let me know if this was helpful or not.

[pluMmet]

SCR*W MR Fudge, it helped me! (sorry fuddgy)
:wavey:

[Mr Fudge]

Thanks Johnny.

I do appreciate that. Really. But been suffering a pretty serious case of RSI at the mo. So trying to keep my pc time to a minimum.

Also my PC has been tied up rendering while I rest so I havn't had a chance to scrutinise the file you posted. The effect looks good and seems to be what I am after....

Caio,
F

[Johnny_Scott]

Glad I could be of service :beer:

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