View Full Version : Creating a galaxy

05 May 2003, 07:08 PM
i have a problem im trying to make a galaxy for this scene and im not getting what i need. i need to have hundreds of thousands of stars with a random size and color. i can't seem to find away to make the emitter emit particle spheres with random size to keep there size and color once they are emitter. on top of that i need to create a glow in the center like there's a huge group of stars close together. And i've tried to animate it too so it rotates like a galaxy but in order fot it to swirl right i have to make a radial fild with a vortex field and they move rather fast and doesn't look to promiseing? basicly every aspect of this scene isn't working for me can anyone please help?:banghead: :insane:

05 May 2003, 08:00 PM
first of all, you'll have to add a custom attribute to your particle.shape object (e.g. radiusPP) to get multiple particles of different sizes.

then add a creation expression like this to control the attribute:

particleShape1.radiusPP=rand (0,1);

the figures in brackets define the range for the random-factor to grow and shrink between when particles get emitted.

increase the amount of particles/sec. to a ridiculously high amount and make those particles be emitted with high speed for a short time.

set the min./max. distance to high values to define the size of the galaxy.

when you're happy with what you got, set your particle-cloud to be in an initial state, apply some fields (vortex/turbulence) and glow to it (hide source?), then render.

btw, cloud or tube work pretty well for render type.


sorry for not goin' into further detail, but i'm too tired typing on.
hope, this helps a little!

05 May 2003, 10:16 PM
what does the initial state do?

05 May 2003, 11:16 PM
It freezes the particles into place, so that when you rewind they start in the same position that you froze them from.

05 May 2003, 11:38 PM
how do you do that?

05 May 2003, 11:51 PM
ok i did the set intial state. but how do i make it so they stop moving when i hit play? cause when i hit play they keep moveing? aslo i applied a vortex field but they exspand out as time goes by how do i keep them from exspanding but still have a vortex effects?

05 May 2003, 02:12 AM
Set the Conserve value of the particles to 0.

The Conserve value tells Maya how much of the particles momentum to use. The default value of 1 means that if you fling some particles out with a field, they'll keep on flying forever until something stops them.

Setting the Conserve to 0 means that particles will only move if something moves them, then they'll stop. Values between 0 and 1 are a mix.

So setting you Conserve to 0 should fix both of your problems. They won't keep moving from the start, and they won't get flung outwards by the vortex. They'll just swirl.

I hope that made sense! :surprised

05 May 2003, 08:50 PM
Jovex, will this createa star field similar to 3dsmax's lens effect? hehe...this particle business r0x.

still posting more than you,

05 May 2003, 10:35 PM
Have you tried the paint effects galaxy brush? The galaxies created are fully 3D and can render faster than an equivalent number of particles. Note that the brush scale needs to be large enough relative to your view to be visible( very small stars are proportionately dimmer specs ). If your camera is moving you should probably render at double resolution and resize down to avoid flicker. These also work with 3D motion blur of the camera, unlike particles.

05 May 2003, 10:43 PM
thanks Jozvex and dunken. i totally forgot about paint effects i'll have to try that!:thumbsup: . thanks a bunch jozvex! im not very educated in dynamics. Thanks a bunch:beer:

05 May 2003, 10:57 PM
Yes you could definitely use the PaintFX Galaxy brush.

The only drawbacks I can see would be contrlol over the motion (ie he wants swirling motion), and rendering if he wants to use Mental Ray. Of course he could convert it to polys, but then things like Glow would become unavailable.

And I just have to add that I think PaintFX is such a completely fantastic feature and is very underused from what I've experienced. Now that you can convert it to polys it's like 10x even more incredible!!!

For my demo reel which I'm working on at the moment, I'm currently working on a scene created entirely out of PaintFX that 'draws itself' into existance as if a little kid were drawing it with markers.

I love it!

05 May 2003, 11:07 PM
you can convert to polys? is this in maya 5? how do you do that?

05 May 2003, 11:21 PM
Yes it's a great new feature in Maya 5!

Modify > Convert > Paint Effects to Polygons

05 May 2003, 03:06 AM
wait, but that still doesnt answer my question...
Who here knows what the 3dsmax starfield lense effect looks like? thats what I want in maya!!!

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