bullet physics for DS 1, 2, 3, 4 PC/Win ... teaser

RAMWolff

I have no idea what you just said except for the last line! lol

mCasual

RAMWolff said:

I have no idea what you just said except for the last line! lol

the low down is

you will be able to install a hinge ( which may be a car axle by the way ) without having to mind how the door / wheel is positioned

Design Anvil - Razor42

This is awesome, if you can briing bullet type physics into Daz you'll make a lot people happy! Including me!
Epic work! Be great to see a mac version tho.

ghastlycomic

Me three!

I'd love to have bullet physics in Daz.

mCasual

Amy yet again serene and completely confident in the safety of the experiment pertaining to hinge2Constraints

RAMWolff

I don't know, looks dangerous to me! YIKES!

olorin_6b059a2331

hey Casual, just came across this, and it's fascinating to watch the process you're going through. i'm new to DAZ, DS and 3D modelling/animation, but i'm sort of generally aware of toolkits and libraries, etc for game engines. what you have looks pretty good to me.

i'm on a Mac, so i'm interested to know why exactly what you did is PC/Win only. as far as i know you can incorporate external libraries via the SDK on either platform. so, are you doing any of the following?

1. using a bullet physics engine library compiled for PC, and most of the scripting/configuration is scripted inside DS, or

2. are you using a PC-based toolchain and script setup (Javascript?/Python?/.NET?) and then just calling the engine within DS?

3. something else?

either way, it doesn't look trivial, but i'd be curious what porting it to Mac would mean in terms of the code requirements.

keep it up - excellent start you have!

scott

mCasual

thingy564 said:

hey Casual, just came across this, and it's fascinating to watch the process you're going through. i'm new to DAZ, DS and 3D modelling/animation, but i'm sort of generally aware of toolkits and libraries, etc for game engines. what you have looks pretty good to me.

i'm on a Mac, so i'm interested to know why exactly what you did is PC/Win only. as far as i know you can incorporate external libraries via the SDK on either platform. so, are you doing any of the following?
1. using a bullet physics engine library compiled for PC, and most of the scripting/configuration is scripted inside DS, or
2. are you using a PC-based toolchain and script setup (Javascript?/Python?/.NET?) and then just calling the engine within DS?
3. something else?
either way, it doesn't look trivial, but i'd be curious what porting it to Mac would mean in terms of the code requirements.
keep it up - excellent start you have!
scott

the "client" is a daz script (very javascript-like ) it can mark objects in the scene as being static or dynamic bodies or constraints
, it can compute their mass. Physical bodies get new properties in their parameters tab, ex: hinges get a drop down list to select which objects are attached to the hinge.

then the script can package all that information and place it in a file named in.txt

---

for the 'server' ( more like a processor for now )

i copied the big Visual Studio 2010 C++ solution, that comes with the Bullet Physics sdk
i stripped everything except support for collisions, dynamics, linear maths
the program gets the Daz Studio physical scene as a text file (in.txt) that looks like

0 Cylinder1 0 0 0 0 0 0 0.707 0.707 0 0.01 0.25 0.01 121 
0 Cube1 27 0 -0.653 -0.762 -0.343 0 0 0.939 0 0.15 0.15 0.15 121 
0 Cylinder3 0 0 0 0.5 0 0 0.707 0.707 0 0.01 0.25 0.01 121 
0 Cube2 27 0 -1.001 0.494 0 0 0 1 0 0.15 0.15 0.15 121 
2 Cylinder1 1 0 0.009 1.003 -1 0 0 
2 Cylinder3 3 0 1.001 0.006 -1 0 0

it creates (instantiates) in the bullet physics world the objects in that list at the positions specified
in this example there's 1 static body 2 dynamic bodies and 2 hinges

it runs the simulation for the number of frames specified ( 121 )

and writes the results in a text file (out.txt) which looks like

body Cylinder1 static
body Cube1 dynamic
body Cylinder3 static
body Cube2 dynamic
0 0 0.000000 0.000000 0.000000 0.000000 0.000000 0.707107 0.707107
1 0 0.000000 -0.656674 -0.759261 -0.345072 0.000000 0.000000 0.938576
2 0 0.000000 0.000000 0.500000 0.000000 0.000000 0.707107 0.707107
3 0 0.000000 -1.001496 0.494033 -0.000017 0.000000 0.000000 1.000000
0 1 0.000000 0.000000 0.000000 0.000000 0.000000 0.707107 0.707107
...
3 119 0.000000 -0.897749 0.056050 0.224813 -0.000000 0.000000 0.974402
0 120 0.000000 0.000000 0.000000 0.000000 0.000000 0.707107 0.707107
1 120 -0.000000 -0.952922 -0.314600 -0.582578 0.000000 0.000000 0.812775
2 120 0.000000 0.000000 0.500000 0.000000 0.000000 0.707107 0.707107
3 120 0.000000 -0.893711 0.047989 0.229199 -0.000000 0.000000 0.973380

once the simulation ends the Daz Studio client script reads out.txt and animates the specified objects

--------

the daz studio script would run on a Mac without modification

i'll almost certainly publish my source code so it wont be hard for any volunteer to compile it for a mac

-------

later i may make a real-time version, since daz studio scripts can establish sustained communication ( stdin/stdout) with external programs

if you look at https://sites.google.com/site/mcasualsdazscripts/mcjwiikit-for-daz-studio-3-pc-version-zero-beta-not-stable-yet
that's how i allowed real-time control of daz studio with a wii-mote
also see https://sites.google.com/site/mcasualsdazscripts2/mcjhidkit for gamepads

eventually i may make a plugin for DS4 and DS3 which will be more responsive

mCasual

currently adding "Hinge 2" constraints

steer and roll with a suspension !

in ODE it's called "A hinge-2 joint"

http://ode-wiki.org/wiki/index.php?title=Manual:_Joint_Types_and_Functions

in Bullet Physics ot's a btHinge2Constraint

http://bulletphysics.org/Bullet/BulletFull/classbtHinge2Constraint.html

olorin_6b059a2331

wow Casual! that's pretty amazing and awesome, i have to say, and it's a good idea to start the project out by offloading processing to a separate app and then send the results back to the Animator in less than real time. overall though it should still be pretty responsive as long as someones not trying to model 3000+ Tenga blocks crashing down. as you refine it you may be able to make it efficient enough to run it in real time with good performance, but it's better to start small and manageable and grow from there.

although i'm not a programmer i understood most of what you're up to. i've never yet compiled anything on the Mac, but i'm definitely getting closer to a point where i'll need to do it. one curious thing for those of us on Macs (and for anyone scared of compiling from source) would be if you could call an emulated version of your Win based app from Daz on a Mac via scripting. i've been able to wrap a number of Win apps up in a standard OS X bundle through Wine and Wineskin - like BVHacker for instance which just _barely_ runs (don't resize the program window or you're doomed). so it makes me a bit curious if a script could call an emulated EXE directly. it's certainly possible to copy a text file within a MacOS bundle and have the emulated program believe it's in the filepath of a Windows machine. so as long as the filepaths were logical to each platform, it would be pretty easy to import the data from within a Wineskin.

anyway it sounds like a really promising plugin. thanks a huge amount and i'll look forward to working with it when i have some time.

scott

mCasual

Amy ... not afraid
a nice scooter looks more interesting than boxes and cylinders
.
.
.

i realized just now i didn't really make this scooter steerable

Eustace Scrubb

Casual said:

Amy ... not afraid
a nice scooter looks more interesting than boxes and cylinders
.
.
.

I realized just now i didn't really make this scooter steerable

So THAT'S why she's riding off the edge in the fourth picture!

mCasual

Eustace Scrubb said:

Casual said:

Amy ... not afraid
a nice scooter looks more interesting than boxes and cylinders
.
.
.

I realized just now i didn't really make this scooter steerable

So THAT'S why she's riding off the edge in the fourth picture!

she's taking all those risks for Science ( and the public good or something )

mCasual

rough ride for the first simulation of the "hinge 2" constraint ( steer, roll and shock absorber )

it just needs stiffer shock absorbers :)

mCasual

not sure yet why the wheels lock

i know that for cars and the likes, bullet suggests we don't use hinges ,

rather use "ray-Casters" meaning the car slides above ground, supported by invisible rays
and i guess, bullet spins the wheels according to the movements

mCasual

i made the bike frame heavier
the rear wheel wider ( wider than shown )
and it looks like it did the trick

i'll give users access to most of the hinge parameters
since default values are not enough to make things work out

patience55

That's working better :-)

mCasual

note that this, albeit simple, 4 seconds/120 frames simulation takes 2 seconds to compute
so eventually if we go real-time, we could play GTA0 in DS

mCasual

new setup for upcoming development

4 the initial release may include support for non-primitives ... say low-poly terrains etc

mCasual

Amy's death defying jump demonstrating Hinge-2 constraints !

http://www.youtube.com/watch?v=vuYMvRh8iGg

also see the giraffianesque version

http://www.youtube.com/watch?v=ZSxLUgnbj8M

patience55

You realize of course that she'll be asking you for danger pay soon ;-)

mCasual

Patience55 said:

You realize of course that she'll be asking you for danger pay soon ;-)

she may need a protective dangerfield

or at least a helmet

( that's actually Nicole Kidman in the 1983 BMX Bandits )

patience55

There goes the hairdo lol ...

mCasual

the physics tests will look better with a brand new bike

soon ( but not that soon ) i'll probably post the bike on my site

patience55

Casual said:

the physics tests will look better with a brand new bike

soon ( but not that soon ) i'll probably post the bike on my site

Oh that's a nice new prezzie for her.

{not to worry you but the uh, giraffe is growing!}

mCasual

Patience55 said:

Casual said:

the physics tests will look better with a brand new bike

soon ( but not that soon ) i'll probably post the bike on my site

Oh that's a nice new prezzie for her.

{not to worry you but the uh, giraffe is growing!}

in the early pics the giraffe was as tall as the ramp then later on it was looking smaller, so i unshrunk it :)

mCasual

Amy's bike promo teaser video YT

https://www.youtube.com/watch?v=VNeHLTwfYmQ

mCasual

so far in the test cases
physical bodies were made of boxes ( or cylinders, spheres, cones, capsules )
now i'll introduce the "triangle meshes"
so you'll be able, for example, to specify that a shirt is a physical object
or that a terrain ( google/youtube-search) for mcjElevate is a physical object
only non-moving objects will be supported for this script version

in the inage below the green surfaces will be our test "triangle mesh"

and Amy is still on board for the experiments with her brand new unchained bike

mCasual

see see ?

exactly like the movie 'Contact'

ok maybe not exactly

mCasual

the moment many-a-few have been waiting for

the physics server became aware of the existence of the green triangleMesh

meaning terrains will be supported ! mountain roads !

and meaning the video where Amy rides her bike don't the ramp is nigh ( ish )