particle gravity experiment - windows 14/02/2004

leon · Post by **leon** » Sat Feb 14, 2004 12:27 pm

OK, following on from the deflector experiment, I've been playing with gravity and particles a bit....... Here's a 2.8mb demo vid.

Particles can now be attracted or repelled from the vertices of a mesh - it's best to stick to very small meshes (i.e. 1-10 vertices) at first, since it can take a while to calculate with larger meshes.

The binary has been updated - as before, extract into a copy of your tuhopuu directory:

http://reblended.com/www/leon/thp_pdef.zip

I've added three new buttons to the particle interaction panel: gravity on / off, gravity strength, and gravity power...

Gravity strength controls how strongly particles are attracted or repelled (choose a negative value for repulsion).

Gravity power controls how quickly the force falls off with distance - for "real" gravity use 2.

It can take a lot of fiddling to get the results looking right - start off with something simple and play with the controls to see what's happening..

Again, you can't animate the meshes which have gravity switched on (although you can still animate the particle source). Also, keep the "particle keys" setting on 32!

Try not to let particles get too close to a "gravity" vertex - the particles tend to fire off in all directions if you do!

Have fun!

Cheers

Leon

nozzy · Post by **nozzy** » Sat Feb 14, 2004 1:41 pm

Again it works very nicely

Would it be possible to incorperate
being able to key the "Gravity - Strength and Fall-off" through an IPO?

It would be great for creating turbulence fields, etc.

/nozzy

gabio · Post by **gabio** » Sat Feb 14, 2004 9:25 pm

I can't belive it! Someone is still working on this old system! Been so long since i heared of developement on effect! that's great! i'll definetly test this out.

ada89 · Post by **ada89** » Sun Feb 15, 2004 11:32 pm

Woaw..this is cool!!!

There some bug in the feature. You can check it in the .blend.
http://sbup.jyscomputers.com/ada89/parbug.blend

Good luck, its rocksss!!!

PS: Is it possible to add more key, more than 32? cause when you increast the life it will not looks good.

levon · Post by **levon** » Mon Feb 16, 2004 9:22 am

wow this is great news for the development of particles in blender. it works quite well once i figured how to use it

i do hope this developes into a particle system similar to the expensive plugings for 3d max.

keep up the great work

ada89 · Post by **ada89** » Mon Feb 16, 2004 7:07 pm

Just test the .blend with Hos build and the bug seem to be gone but when i render the glow of the particle seem to overcome the tube which make it look bad.

Anyway, GJ

ada89 · Post by **ada89** » Tue Feb 17, 2004 12:26 am

And found another bug, the particle seem to be through the mesh:

http://sbup.jyscomputers.com/ada89/part/partest3.blend

Money_YaY! · Post by **Money_YaY!** » Tue Feb 17, 2004 2:40 am

Neat picture!

leon, can you make a patch file ? You were making them for the first of your work, and now the first part is in tuhopuu, but the new gravity stuff is not.

theeth · Post by **theeth** » Tue Feb 17, 2004 2:44 am

Money_YaY! wrote:leon, can you make a patch file ? You were making them for the first of your work, and now the first part is in tuhopuu, but the new gravity stuff is not.

I'll second that. Also, if you haven't read my last commit log, there's some things I'd like you to change in your code. Just contact me by e-mail for further detail.

Martin

leon · Post by **leon** » Tue Feb 17, 2004 1:17 pm

hi all,

apologies for the delay, I've been really tied up with work the last few days!

I wanted to hold off on the patch until after the merge, so I didn't do a patch this weekend, and haven't had a chance since!

theeth - many thanks for taking a look at the code, I'll send you an email....

Ada89 - thanks for the blends: they're a great help in trying to find out where things are going wrong! btw, the problem with the tube may just be the fact that the tube is only a single plane thick (I think particles will be seen through a plane if they are close to it). Maybe you could try enclosing the deflector in a tube with a bit of thickness, see if that helps?

I will try and spend some time on this tonight, and hopefully will have a new patch ready tomorrow night sometime.

Cheers!

Leon

ada89 · Post by **ada89** » Tue Feb 17, 2004 3:14 pm

leon wrote:btw, the problem with the tube may just be the fact that the tube is only a single plane thick (I think particles will be seen through a plane if they are close to it).

It works ok in Hos's build

My other test .blend if you want to see:
http://sbup.jyscomputers.com/ada89/part/partest2.blend

Good luck

Apollux · Post by **Apollux** » Wed Feb 18, 2004 4:04 am

leon, speaking of the Particles deflector thing (wich I JUST LOVE

) ... certainly the fact that some partices manage to pass trough the deflector is a bug right now, but I can think of many (and I do mean MANY) situations when one would like exactly that to happen (particles passing trough the deflector).

So, it si possible to add a third slider to the mesh, something called "permeability" that controls how hight are the chances for a particle to pass trough the deflector?

Let's say that when "permeability" is set to 0.0 not a single particle could pass trough, but when set to 1.0 ALL particles would pass trough. Is that possible?

leon · Post by **leon** » Thu Feb 19, 2004 2:31 pm

sorry all, I haven't had a moment to work on this so far this week (work has been deadly!!!)

Apollux, I like the idea of "permeability" and it should be pretty simple: will try and put this in this weekend. Also, I was thinking about another slider for adding a certain amount of randomness to the bounce, and I'll have a play with that too. Any other ideas welcome!!!

Should have a patch for gravity ready this weekend too.

cheers

leon