MSPhysics 1.0.3 (16 October 2017)

Mister K · 1 Jun 2014, 11:01

Joints in Newton are constraints. Its impossible to make them 100% stiff, but the softness/stiffness can be controlled. From current observations, joints are more stiff with the solver model set to exact, but pretty soft and unstable when the solver is passive. I'm aware there is an error somewhere in the constraint behavior, but meanwhile I can't clarify you on distinctive stuff. Let's continue discussion on joint flexibility once I'm done integrating them to MSPhysics.

OK, just a couple tiny things to think on as you are implementing the joints.
Can you easily swap out or add joints while simulating? Say you wanted a wheel/arm to lock in place after it moved a certain distance at that point you could attach a "fixed" joint that would lock everything in place (in SP anyway), is that doable or can perhaps even be done better with something else?

Another problem in SP was "weight"(size x density) of an object would determine joint stiffness as well, could that be manipulated when calculating joints without disrupting the entire models weight balance?

Anton_S · 1 Jun 2014, 17:53

@mister k said:

Can you easily swap out or add joints while simulating?

Yes, each joint is a class. Creating/removing joints will be easy during simulation, @my_jnt = Hinge.new(pos, pin_dir, parent, child, min = 0, max = 0, friction = 0)
You will be able to do @my_jnt.#connect, or @my_jnt.#disconect.

To get all joints within the body you would write Body.#get_joints. To get all joints the body is connected to, you would write Body.#get_connected_joints.

It will be quite easy to use the joint interface.

@mister k said:

Another problem in SP was "weight"(size x density) of an object would determine joint stiffness as well, could that be manipulated when calculating joints without disrupting the entire models weight balance?
I'll look in to it

Sofia Oliveira · 6 Jun 2014, 10:48

Hi! I am a student of electrotechnical engineering and i'm doing a project. I need a little help! How i get values from serial port to MSPhysics?

Anton_S · 6 Jun 2014, 18:30

@sofia oliveira said:

Hi! I am a student of electrotechnical engineering and i'm doing a project. I need a little help! How i get values from serial port to MSPhysics?

thomthom · 6 Jun 2014, 18:39

@sofia oliveira said:

Hi! I am a student of electrotechnical engineering and i'm doing a project. I need a little help! How i get values from serial port to MSPhysics?

Would help to be a bit more specific, like what data are you getting from the serial port and what do you want to use that data with in MSPhysics?

Sofia Oliveira · 15 Jun 2014, 22:27

@thomthom said:

@sofia oliveira said:

Hi! I am a student of electrotechnical engineering and i'm doing a project. I need a little help! How i get values from serial port to MSPhysics?

Would help to be a bit more specific, like what data are you getting from the serial port and what do you want to use that data with in MSPhysics?

Data from an accelerometer to move an object in MSPhysics.

Anton_S · 15 Jun 2014, 23:10

@sofia oliveira said:

Data from an accelerometer to move an object in MSPhysics.

I assume your speaking of the accelerometer that returns its own acceleration along three axis, am I right?

The main problem were facing now is how to get accelerometer data into SketchUp?
I don't know about Macs, but on PC we use Microsoft Windows API, [Raw Input](http://msdn.microsoft.com/en-us/library/windows/desktop/ms645536(v).

The next question is using this accelerator data to control velocity of the particular body in MSPhysics. Of course, accelerometer data may be used for other purposes, but I assume you want to control body velocity with it. For instance, you move accelerometer to the right, the body moves to right as well.

I'm sorry to say, but current version (0.1.0) of MSPhysics doesn't have a scripting feature, so we'll write the code for SketchyPhysics. I assume you have sketchy physics 3.2 installed on SketchUp 7 or on SketchUp 8.

Before I attempt to write a script, I want you to verify what kind of accelerometer you're using. Perhaps a url to where you bought it would be helpful.

Sofia Oliveira · 17 Jul 2014, 11:46

@anton_s said:

I assume your speaking of the accelerometer that returns its own acceleration along three axis, am I right?

The main problem were facing now is how to get accelerometer data into SketchUp?
I don't know about Macs, but on PC we use Microsoft Windows API, [Raw Input](http://msdn.microsoft.com/en-us/library/windows/desktop/ms645536(v).

The next question is using this accelerator data to control velocity of the particular body in MSPhysics. Of course, accelerometer data may be used for other purposes, but I assume you want to control body velocity with it. For instance, you move accelerometer to the right, the body moves to right as well.

I'm sorry to say, but current version (0.1.0) of MSPhysics doesn't have a scripting feature, so we'll write the code for SketchyPhysics. I assume you have sketchy physics 3.2 installed on SketchUp 7 or on SketchUp 8.

Before I attempt to write a script, I want you to verify what kind of accelerometer you're using. Perhaps a url to where you bought it would be helpful.

My accelerometer is a MPU9150 which is actually an IMU. My idea is, having a board with the MPU9150 and a Bluetooth Low Energy module (CC5541) that sends the values to a USB/BLE dongle (CC2540). The dongle is recognized by Windows as a Serial Port (COMxx). We master the Bluetooth component but we can’t get the accelerometer data into Sketchcup.

We’ve made a DLL in C# that is able to get data from the IMU (via Bluetooth) and compute a x,y,z position from both accelerometer and gyroscope data. We would like to use this x,y,z coordinates to move a shape inside Sketchcup.

My goal is that Sketchup, with these IMU values, make a movement on an object.

Anton_S · 17 Jul 2014, 12:22

@sofia oliveira said:

We’ve made a DLL in C# that is able to get data from the IMU (via Bluetooth) and compute a x,y,z position from both accelerometer and gyroscope data. We would like to use this x,y,z coordinates to move a shape inside Sketchcup.

My goal is that Sketchup, with these IMU values, make a movement on an object.

Looks like you're half way done already Can you post a function name you're willing to export from the dll (with parameters and return type), plus the dll itself. We could use Ruby DL to extern function into Ruby and then teleport the desired entity according to the [x,y,z] coordinates.

Open SketchyPhysics in SU6, 7, or 8.
Copy this code into the desired body, the body you want to be moved.
Change path and name to the desired dll path.
Change dll function_name to the desired name.


module MyRawInputC
  extend DL;;Importable

  dlload('C;/[path]/[dll_name].dll')
  extern "void func_name(float*)"

  def self.read_accelerometer_pos
    buf = (0.chr*12).to_ptr
    func_name(buf)
    Geom;;Point3d.new(buf.to_a("F3"))
  end
end unless defined?(MyRawInputC)

ontick {
  teleport(MyRawInputC.read_accelerometer_pos)
}

Press play and see if it works.
If you having troubles, upload the dll and show the function name (with params) you want to export and I'll modify the script.

deaneau · 2 Aug 2014, 11:30

@unknownuser said:

Do you know that you have also a Physic engine (Bullet) for Sketchup inside Simfonia ?
(free version is existing)

hello pilou,

not realy free, only a free trail.

dean

Fred_Flintstones · 4 Aug 2014, 04:40

How's it coming along?

Anton_S · 6 Aug 2014, 11:03

@fred_flintstones said:

How's it coming along?

I currently finished enchanting the MSPhysics Scripting API. As well, I finally finished with the body and simulation dialog.

Tested some cloth, just for fun.

The Newton cloth and soft bodies feature is not complete yet. The collisions, body transformation, stiffness and other deformidable body properties are not done. Bullet physics engine seems a promising option, after all. I might migrate to Bullet, but not after version 1.0.0, or else this will never get finished.

And some custom cloth.

I'm left with joints for this version. I did start integrating Newton joint API, but it seems I did it incorrectly.

pibuz · 6 Aug 2014, 12:11

Well this is really awesome! Testing for some clothes! Thanks a lot!

solo · 6 Aug 2014, 17:23

Cloth simulation in SU?

You are on the verge of being a superstar, much anticipation for this feature

Anton_S · 6 Aug 2014, 17:26

@solo said:

Cloth simulation in SU?

You are on the verge of being a superstar, much anticipation for this feature

SU is very powerfull for such purpose.

solo · 6 Aug 2014, 17:41

Imagine to amount of table cloth, curtains and unmade beds in the 3D warehouse soon.

andybot · 6 Aug 2014, 18:51

I've been following this thread with quite some amazement. This is so very impressive, keep up the great work!!

Fred_Flintstones · 7 Aug 2014, 08:32

@anton_s said:

I'm left with joints for this version. I did start integrating Newton joint API, but it seems I did it incorrectly.

Aww that's to bad...But good to see how much you've done... GL with the joints!

Gonthim · 4 Sept 2014, 11:18

Just curious about the release date. I certainly don't want to sound like I'm complaining though. Just dying to get my hands on this ASAP. It looks amazing.

pilou · 4 Sept 2014, 12:45

Missed this advanced one! Cool!