Need Help For A Flocking System.

[Symbolic]

Hi,

I have tried to post my questions on another post. But I think it became complicated and messy.

So I will try this again.

This is becoming a major problem for me. Since this is my project at school. I have to find a solution in a very short time. So... Please help me!!!

In order to be able to illustrate the problem in a better way. I will split the things in two:

1) The Particle System:

The particles will move on a flat surface (a wall). At a specific time they will start flying away from the wall.

2) Instancing Behavior.

I will have flies instanced to the particles. They will walk on the wall. Then they will fly away from the wall.

//

Ideas:

There will be two *.bgeo sequences. (a) walking, ( flying

First the instances will have the WALKING sequence. Lets say 50 different states. State 25 will be a rest position. This is where I want to switch to the FLYING cycle. The flying will be another 50 different states. But the position of the legs of the flies when it is flying and walking will be the same.

So lets say that at frame 225 the time for the flies to switch from WALKING to FLYING will come. Each instance will look at its state. If it is at position 25 it will immediatelly switch to the FLYING sequence. If it is before position 25, it will wait until it is at position 25 and then switch.

Another important thing is maybe grouping. I will have to have two particle groups. (A) walking and ( flying. They will have different forces. WALKING will be just moving on the wall, FLYING will be moving away from the wall. At the beginning all particles will be at the WALKING group. Each point will then switch from group WALKING to gropu FLYING as its instance switches from the WALKING cycle to the FLYING cycle.

//

I think I will be able to blend the two different *.bgeo sets in chops. But the other thing... I do not have any idea how it will be done!?! Oh! My! God!

I guess... Attributes? Expressions?!

//

This is a very long post. I know that! But I need help. Any ideas may save my life.

Thanks.

[grasshopper]

Hi Symbolic,

OK, you said you were in a hurry so here's a quick suggestion if it helps but I haven't tried it myself. Maybe it will prompt someone else to respond ...

I'm assuming you are going to have many flies in your scene and that they are going to be not that close to camera. Also you will render with motion blur which will hide transitions.

So you could use a blend from the walking to the flying sequence over a few frames without caring which part of the sequence you are in. For this to work your walking and flying bgeo sequences need to be made from the same base model (i.e same point count and topology). It also helps if the walk and flying cycles are the same length but it isn't essential.

As you are instancing you will need to disable the instancing during the transition phase only (say five frames or so) and substitute the blend instead. One way to do this is to have an attribute on your particles that stands for 'airborne''. Set this to zero when they are walking and to 1 when they are flying. Then instance the walk cycle when at 0 and the flying cycle when at 1. Make the attribute increase steadily from 0 to 1 over a few frames when you want the blend to happen (i.e. increase the value as the particle leaves the wall in your simulation). When the 'airborne' value is blending (i.e. somewhere between 0 and 1) disable instancing. Then in SOPs work out your blend. You can do this using a BlendShapes SOP with your walk and flying cycles set as inputs. Use the 'airborne' attribute in the blend0 and blend1 parameters to control the transition (one will be '1-airborne' and the other 'airborne'). Make sure 'Blend Position' is enabled. If you group all of the particles that are in the transition phase you can run them all through this blend process and render them as standard geometry then you can carry on instancing as normal the non-transitioning group.

Just throwing some ideas out there. If I had more time right now I would try this out. Maybe you could package up a hip file you could post on here for some of us to take a quick look at?

John.

[Symbolic]

Hi!

Thanks. I will try to figure out some way of blending. Your are right... the switch it does not have to be so precise and correct.

The problem that I am trying to solve now is the bugs walking on the wall and feeding the speed of the points into the playback speed of the copied geometry.

Please look at my post "Reading The Velocity Of The Particles."

at:

http://forums.odforce.net/index.php?showtopic=5011

I have some files and examples there.

Thanks!