2 KinematicBodies not colliding Newton 3

[Lax]

Hi,

I'm using the latest Newton 3 version and have a simple scenario, in which I have 2 kinematicbodies.
But somehow they do not collide anymore. As far as I remember. It worked in the past.

Strangly in the debug modus, as soon as I start my simulation. I get the following assert:

Code: Select all

void dgSkeletonContainer::Finalize(dgInt32 loopJointsCount, dgBilateralConstraint** const loopJointArray)
{
   dgAssert(m_nodeCount >= 1);

   const dgDynamicBody* const rootBody = m_skeleton->m_body;
   dgAssert (((rootBody->GetInvMass().m_w == dgFloat32 (0.0f)) && (m_skeleton->m_child->m_sibling == NULL)) || (m_skeleton->m_body->GetInvMass().m_w != dgFloat32 (0.0f)));


It says that the m_skeleton->m_child is NULL how can that be? I tried the kinematicbodies demo, and in this demo finalize is never called. Why is it called in my simulation?

I also set for both kinematic bodies:

Code: Select all

NewtonCollisionSetMode(collision, 1)


and I integrate the velocity for both bodies.

I hope someone can help on this issue!

Best Regards
Lax

[Julio Jerez]

Are you trying to attach joints to kinematic bodies?
That is not allowed in 3.xx

In 4.00 is but that's because all bodies are kinematic.
Still two kinematic bodies do not collide.

[Lax]

No, I do not attach joints. Just want to collide two characters and react on collision.

Still two kinematic bodies do not collide.

Do you mean, it is not possible, that 2 kinematic bodies collide?
So there must be one rigid body involved?

[Julio Jerez]

Do you mean, it is not possible, that 2 kinematic bodies collide?
So there must be one rigid body involved?

yes, they never had in 3.xx

if you look at function
void dPlayerController::ResolveCollision(dPlayerControllerContactSolver& contactSolver, dFloat timestep)

you will see that it calculates collision of the player by itself, not as end engine narrow phase function.

this also apply to 4.00, however in 4.00 player and triggers are sdk class objects so for the app view point they collide with players and triggers and any other body because they are part of the broad phase and calculate the contacts.

this is possible in 4.00 because the update happens after contacts are calculated while in 3.xx
after contacts are calculated what follows is the contact resolution (solver), so there is not chance for the engine to process special objects like players, triggers, vehicles, etc.

are you using dPlayerController?
is so them players should collide with other players.

[Lax]

Hi Julio,

thanks for clarification!

are you using dPlayerController?
is so them players should collide with other players.

No I didn't but in that case I will use the player controller.

Best Regards
Lax

[Julio Jerez]

has you tried 4.00
I solve many of the issue that you might be having, and it is a lot easier to use than 3.xx
for once is full c++, so not more dreaded c++ callbacks
and player controller work so much better, so if you are going to make that kind of change, give it a try to 4.00

[Lax]

has you tried 4.00
I solve many of the issue that you might be having, and it is a lot easier to use than 3.xx
for once is full c++, so not more dreaded c++ callbacks
and player controller work so much better, so if you are going to make that kind of change, give it a try to 4.00

Unfortunately not. Because I would need to re-write the whole OgreNewt. And I'm afraid in doing that. Because in the past. I got an almost finished OgreNewt and just adapted lots of thinks. But I have no idea how re-write everything. I also do not have that time anymore .

Or has somebody in the community start to re-write OgreNewt to newton 4.0?

Back to the issue:
- I created now 2 player controller. At least they do collide. But I get no contact data, that the collision occurred. Is this also not possible?
I need to react, when the two player controller collide.

[Julio Jerez]

oh, I see OgreNewt


ok, now that you have the player, it is like normal cpp programing, you subclass form the basic player
and you override the methods that you wnat to customize.

in the demo, file ..\newton-3.14\applications\demosSandbox\sdkDemos\demos\BasicPlayerController.cpp
does that
function
dFloat ContactFrictionCallback(const dVector& position, const dVector& normal, int contactId, const NewtonBody* const otherbody) const

will be called on collision, and you get the secund body.

[Lax]

Ok thanks for the infos!

[Julio Jerez]

u

Or has somebody in the community start to re-write OgreNewt to newton 4.0?

I am familiar with the first version of OgreNewt. I helped Wallaber write it about 15 years ago,

Maybe I can make that update, and added to some git hub branch
I downloaded Ogree, and I see that the cmake script can make the solution much easier that in the pass.
But I could not find any link to OgreNewt, In the Ogree forum I see that all question are redirected to a channel that not one reads. so how to I get OgreNewt?

I was able to build after disabling some pugins. but the after that no sure how to add OgreNewt.
I assume is some kind of component

[Lax]

Hi Julio,

I have the newest OgreNewt version, which is working with the newest Ogre 2.x version.
You can download everything here:

https://sourceforge.net/p/nowa-engine/svn/HEAD/tree/external/
See OgreNewt3_0 folder.

There is also lots of code how I use OgreNewt. I did not change since the last 15 years.

Another question:
In my Player Controller, which is derived from dCustomPlayerControllerManager I'm using:

Code: Select all

virtual dFloat ContactFriction(dCustomPlayerController* const controller, const dVector& position, const dVector& normal, int contactId, const NewtonBody* const otherbody)


This called and working fine. But the function:

Code: Select all

virtual bool ProccessContact(dCustomPlayerController* const controller, const dVector& position, const dVector& normal, const NewtonBody* const otherbody) const


Is never called, so I cannot react when 2 player collided. Is there a bug?

Best Regards
Lax

[Dave Gravel]

Hi Lax,
I have take a quick look in the OgreNewt3_0 code.
From what I see the player implementation is not UpToDate for use with the last newton 3.14.

I think the ProccessContact don't exists anymore in the last version, Or it is implemented differently with a other name.

I think now it use something like:
PreUpdate
PostUpdate
Take a look in this file (dPlayerController.h, .cpp) you can see how it is implemented in the last newton 3.14 version.
AdvancedPlayerController.cpp
AnimatedPlayer.cpp

Look at this implementation class too.
class dAdvancedPlayerController: public dPlayerController

I think the vehicle or any other controllers implementation in OgreNewt3_0 can need similar updates for work correctly.

[Lax]

Hi Dave,

Oh yes, you are right. I'm still using the old system und will upgrade.
Thanks for pointing it out!

Best Regards
Lax

[Lax]

Ok, I adapted the player controller to derive correctly and movement is working.
But know I have a big issue. I'm using now the correct:

Code: Select all

dFloat ContactFrictionCallback(const dVector& position, const dVector& normal, int contactId, const NewtonBody* const otherbody) const


It also works for one player controller and rigid bodies. But It does not detect, if a player controller collided with another player controller, which inside is a kinematic body. The collision detection itself does work, the other player will be moved away if I collide with it, but ContactFrictionCallback is not called.
How can this be fixed?

Another question: As I have two player controller. Should I have just one PlayerControllerManager which is adding a PlayerController with AddRoot(...) 2 times? Or can each PlayerController can have its own PlayerControllerManager?

Best Regards
Lax

[Julio Jerez]

Hi Julio,

I have the newest OgreNewt version, which is working with the newest Ogre 2.x version.
You can download everything here:

https://sourceforge.net/p/nowa-engine/svn/HEAD/tree/external/
See OgreNewt3_0 folder.

Lax

Cool, is that you game?

I will lift igrenewt3 ans see if I can make an ogrenew4 from it with the same interface or as close as possible.
So this way should be a drop in.
Newton 4 can coexist with older versions, so the risk should be very minor.

I see if I do ot over the weekend and load it with the sdk in a folder.
I was think of doing thar for some time, so maybe I start with old ogree.

You say this is ogre 2. But what I download in the ogre forum say agree 13.

Am I getting something wrong?