3oo plus animated dominoes. Made the dominoes a while back and gave up animating
them because placing them wasn't very much FUN. I started back up because making
small sets that create simple shapes was! If you create a group of these sets
then you can place a lot of dominoes fairly quickly.
 I tried to get the video size down small enough to attach here, but couldn't.
So I put it on YouTube. Hope you enjoy it.

Video link
https://youtu.be/gJtzmqIOLw8


Have Fun :)

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"Leroy" <whe### [at] gmailcom> wrote:
> Video link
> https://youtu.be/gJtzmqIOLw8
>
>
> Have Fun :)

I too like to simulate and render dominoes inside the bullet physics playground,
see:

  https://youtu.be/B7EtmXFeUE0

Happy POVing!

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Attachments:
Download 'screenshot_20260430_000330.png' (227 KB)

Preview of image 'screenshot_20260430_000330.png'

"koppi" <jak### [at] gmailcom> wrote:
> "Leroy" <whe### [at] gmailcom> wrote:
> > Video link
> > https://youtu.be/gJtzmqIOLw8
> >
> >
> > Have Fun :)
>
> I too like to simulate and render dominoes inside the bullet physics playground,
> see:
>
> https://youtu.be/B7EtmXFeUE0
>
> Happy POVing!

And did he work on this BPP terminal?

Post a reply to this message

"koppi" <jak### [at] gmailcom> wrote:
> "Leroy" <whe### [at] gmailcom> wrote:
> > Video link
> > https://youtu.be/gJtzmqIOLw8
> >
> >
> > Have Fun :)
>
> I too like to simulate and render dominoes inside the bullet physics playground,
> see:
>
>   https://youtu.be/B7EtmXFeUE0
>
> Happy POVing!

Cool! The music was a good touch. I should have put some sound on mine, but I
got lazy. What I thought of doing is make the sound of a domino hitting the next
and sliding down. Then use that sound in sync with the dominoes movement. Maybe
one of these days.
 I was wondering how you place the dominoes. I use a spline for placement. I
have my dominoes placed 2 pov units apart. That because I don't use true physics
to move the dominoes. With them spaced evenly I could simplify the movement
function.
 Noticed that your dominoes have different spacing, they got tighter toward the
center. Your physics engine did a good job of dropping them. I also like the
wiggle the engine gave to the already down dominoes.

Have Fun!

Post a reply to this message

"Leroy" <whe### [at] gmailcom> wrote:
>  I was wondering how you place the dominoes. I use a spline for placement. I
> have my dominoes placed 2 pov units apart. That because I don't use true physics
> to move the dominoes.

Archimedean spiral calculation is used to create the control points [1]:

  [... line 47]:
  local angle = (i - 1) * 0.09
  local radius = 5 + angle * 0.95
  cp = {
    x = math.cos(angle) * radius,
    y = y_pos,
    z = math.sin(angle) * radius,
  }
  [...]

The control points are then fed to the Catmull-Rom spline function [2] with the
tension parameter set to 0.5.

>  Noticed that your dominoes have different spacing, they got tighter toward the
> center.

I would like to have equal spacing between the dominoes, but I do not know how
to calculate that, do you have an idea?

> Your physics engine did a good job of dropping them. I also like the
> wiggle the engine gave to the already down dominoes.

I have been experimenting with different parameters for the friction,
restitution, linear and angular damping of the dominoes, currently using:

  friction = 0.01
  restitution = 0.01
  damp_lin = 0.5
  damp_ang = 0.01

Kind regards,
koppi

--
[1]
https://github.com/bullet-physics-playground/bpp/blob/b558bdf8e8ab23a1438d0162d40c7f0029eb3efd/demo/basic/11-domino.lua

[2]
https://github.com/bullet-physics-playground/bpp/blob/b558bdf8e8ab23a1438d0162d40c7f0029eb3efd/demo/module/spline.lua#L
134

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"koppi" <jak### [at] gmailcom> wrote:

> I would like to have equal spacing between the dominoes, but I do not know how
> to calculate that, do you have an idea?

Luckily, I have played a lot with spirals, and needed to address this issue when
implementing Marschner's wood texture.

Here's a little scene that calculates the arc length along the spiral and uses
that to control a pigment {function {}}.

Hopefully you can see how that's all daisy-chained together and can use that to
place your dominoes.

- Bill

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Attachments:
Download 'spiralpattern.pov.txt' (4 KB)

"Bald Eagle" <cre### [at] netscapenet> wrote:
> Hopefully you can see how that's all daisy-chained together and can use that to
> place your dominoes.

Oh Bill, thank's for the inspiration!

I just added the arc_length and solve_theta_for_arc functions to my Lua code:

https://github.com/bullet-physics-playground/bpp/commit/2b52508742249fe96dc48f6aa3b2ef5ab3867bd0

It works! - see attached screenshot, jippie!

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"koppi" <jak### [at] gmailcom> wrote:
> It works! - see attached screenshot, jippie!

Video link
https://youtu.be/coJWp8DlpFU

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"koppi" <jak### [at] gmailcom> wrote:

> It works! - see attached screenshot, jippie!

Excellent.

I see that the dominoes are positioned at an angle, and that spot around the
270-degree mark has a marked discontinuity, and so those dominoes get shot out.

Can you position the dominoes so that they are perpendicular to the normal of
the spiral?  Or is the imperfectness of their placement a "feature" for more
realism?

- BW

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"Bald Eagle" <cre### [at] netscapenet> wrote:
> Can you position the dominoes so that they are perpendicular to the normal of
> the spiral?  Or is the imperfectness of their placement a "feature" for more
> realism?

I just have fixed the domino orientation along the spiral as you have suggested,
for the changes see:

https://github.com/bullet-physics-playground/bpp/commit/e37fa0de7a0b94d2233428c690e93d29322b2154

Kind regards,
koppi

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