## Random motion between populations objects

Started by Ariel DK, November 29, 2019, 11:15:03 am

#### Ariel DK

##### November 29, 2019, 11:15:03 amLast Edit: November 29, 2019, 11:21:15 am by Ariel DK
Just in case you didn't saw it yet, this is my Black Hole animated scene: https://planetside.co.uk/forums/index.php/topic,26924.0.html

If you notice the debris, you can see that many of them are moving "together", which is not the wanted result. get those objects members of the "debris" population moving randomly each other like in zero-G, it becomes more difficult than i expected. i have just one idea to this, and is decrease the number of objects per pop, and create more pops with different animations, but of course, i would like to know if there is another procedural way to animate this ones...
Edit: Hope i've not asking some stupid thing
Hmmm, what version of Terragen does God use?

#### Dune

##### November 29, 2019, 12:13:44 pm #1
Is your pop of debris sitting on some 'floating' fractal? Then maybe the fractal itself can be warped or animated to have the debris float several ways (and/or rotated!), plus the overall movement.

#### Ariel DK

##### November 29, 2019, 12:57:39 pm #2
Quote from: Dune on November 29, 2019, 12:13:44 pmIs your pop of debris sitting on some 'floating' fractal? Then maybe the fractal itself can be warped or animated to have the debris float several ways (and/or rotated!), plus the overall movement.
Yes Ulco, they are setting by a "floating" power fractal. unfortunately i already tried that idea today. the result was a more random motion of the objects, the problem was that they suddenly changed direction crazly, this could be due that the objects are displaced BY the PFS, and not moving WITH the PFS. the real movement of each object is done by the manual animation that i did inside their nodes, which as you saw, is not 100% realistic...
Hmmm, what version of Terragen does God use?

#### Matt

##### November 29, 2019, 07:49:26 pm #3
Quote from: Ariel DK on November 29, 2019, 12:57:39 pm
Quote from: Dune on November 29, 2019, 12:13:44 pmIs your pop of debris sitting on some 'floating' fractal? Then maybe the fractal itself can be warped or animated to have the debris float several ways (and/or rotated!), plus the overall movement.
Yes Ulco, they are setting by a "floating" power fractal. unfortunately i already tried that idea today. the result was a more random motion of the objects, the problem was that they suddenly changed direction crazly, this could be due that the objects are displaced BY the PFS, and not moving WITH the PFS. the real movement of each object is done by the manual animation that i did inside their nodes, which as you saw, is not 100% realistic...

To create linear motion of each instance, I would do the following. Create 3 power fractals to generate X, Y and Z displacements. You can think of these displacements as your velocities. Then animate the displacement amplitudes of these fractals (e.g. continually increasing) to turn the velocity into a displacement. If the amplitudes animate linearly, the position will animate linearly too. You can add these animated fractals to your base position fractal(s) which don't animate.
Just because milk is white doesn't mean that clouds are made of milk.

#### Dune

##### November 30, 2019, 02:05:33 am #4
The animated displacements of each fractal taken through a redirect shader, I presume.

#### Ariel DK

##### November 30, 2019, 12:09:00 pm #5
Thanks Matt for the advice! and Ulco for the hint

Seems to work nicely, but i noticed that the problem is the rotation.
now i have more control about the linear movement of the objects, but some of them are still rotating together...
Hmmm, what version of Terragen does God use?

#### Dune

##### December 01, 2019, 02:31:47 am #6 Last Edit: December 01, 2019, 02:35:29 am by Dune
Maybe the displacement sizes are not small enough. With more diversity in animated displacement, and rotation the instances should react on a smaller scale. But don't forget using a compute normal/compute terrain with a very small patch size in that case! Pop should sit on that compute node.

Though rotation will likely not be lineair, but more like haphazard rotation. I don't know how to get each instance to really rotate in different ways constantly. Then you probably need a few copies of a pop and have them rotate differently.

Mind you, I've never done this, purely theoretcal.

#### Ariel DK

##### December 01, 2019, 02:48:00 pm #7 Last Edit: December 01, 2019, 02:51:41 pm by Ariel DK
Quote from: Dune on December 01, 2019, 02:31:47 amMaybe the displacement sizes are not small enough. With more diversity in animated displacement, and rotation the instances should react on a smaller scale. But don't forget using a compute normal/compute terrain with a very small patch size in that case! Pop should sit on that compute node.

Though rotation will likely not be lineair, but more like haphazard rotation. I don't know how to get each instance to really rotate in different ways constantly. Then you probably need a few copies of a pop and have them rotate differently.

Mind you, I've never done this, purely theoretcal.

I will try to check that this night, meanwhile, this is an animation with your recommended setup. is only one pop, but as i said before, some of them are still rotating together.
At least i can't say that doesn't looks better than before
Hmmm, what version of Terragen does God use?

#### Oshyan

##### December 01, 2019, 03:00:03 pm #8
It's interesting that the instances are still aligned. Are you using rotation variation in the population?

- Oshyan

#### Dune

##### December 02, 2019, 02:46:00 am #9
Even if so, I notice in pops of trees that with a 'bad' seed and only a couple of instances, you may have bad luck and three prominently located trees have exactly (or nearly so) the same rotation, and need editing.
So you might try editing some initial instances away from eachother, and see if that also influences rotation.

#### Ariel DK

##### December 03, 2019, 01:04:36 pm #10
@Oshyan Yes i did, but in some cases the objects was aligned, and i didn't know why...

@Dune  So yes, i noticed that the instances rotating together was just a few ones, so i corrected manually and surprise...! they were still rotating but from the new angle that i gave them!

Btw, i added more debris model variation, a new edited pop of curse, and not relevant, but i also add some chromatic aberration just for fun