[solved] Joints not working.

[AnniXa]

Hello, i just try to make some bodys with joints together, so i was very lucky to found this example:

 

http://www.leadwerks.com/wiki/index.php?title=CreateJointBall

 

but for any reason even the sample wont work: the cubes are all falling down B)

 

Maybe this is out of date?

 

What do i need to do, for joining the balls together like a chain in the screenshot?

[Canardia]

The C++ example works fine:

http://www.leadwerks.com/werkspace/page/Documentation/le2/_/command-reference/joints/createjointball-r252

[AnniXa]

ty for your help, i was not able to find any relevant difference between the cpp and the bmx sample.

maybe i need to call some init function or something when using joints in bmx?

[Canardia]

I used LEBuilder to make the CodeBlocks example for Rotating Cube, and replaced the code by pasting the BallJoint example there, and it worked.

I didn't try the BlitzMax example, because I don't use BlitzMax anymore. But maybe the LEBuilder BlitzMax cube example will work too.

[AnniXa]

ty, that was worth a try B)

 

i did the same, used the sample with the rotating cube, and just pasted the code from the bmx joint sample in.

 

thats what i get:

 

 

LW and stuff seems to work fine, also the physics stuff, the cubes falling down, but they are not chained together with joints, like they should, they just fall down, instead of hanging on the "crane" thingie.

[klepto2]

Hi, this is the result if you didn't copy the "JointLibrary.dll" into your application folder.

[Canardia]

I tried the BlitzMax example too, and it works fine also.

I had to fix these lines though, because someone who made the example made it only for vsync hardcoded PCs, and mine is vsync free (like most hardcore gamer's PCs are), so this vsync free code works on all PCs:

If KeyHit(KEY_SPACE)
AddBodyForce(cubePhy[Rand(9)],Vec3(10000,0,10000),0)' apply force
End If

UpdateAppTime() 
UpdateWorld(AppSpeed())

[Josh]

I just tried this, and the ball joints are holding the chain together:

SuperStrict
Framework leadwerks.ENGINE 
Graphics 640,480 

RegisterAbstractPath "C:\Leadwerks Engine SDK"


RegisterAbstractPath AppDir 
If Not CreateWorld() RuntimeError "Failed to create world." 
Local camera:TCamera=CreateCamera() 


Local buffer0:tbuffer=CreateBuffer(640,480,BUFFER_COLOR0|BUFFER_DEPTH|BUFFER_NORMAL)

MoveEntity    Camera, Vec3(0,40,-30) 
RotateEntity  Camera, Vec3(45,0,0),0 

SetShadowQuality(1)

Local light:tlight=CreateDirectionalLight()' Create light
MoveEntity (Light, Vec3(0,10,0) )
RotateEntity (Light, Vec3(45,45,0) ,0)
EntityColor(Light, Vec4(1))
AmbientLight (Vec3(.2,.2,.3))

Local ground:tentity= CreateCube()' Ground
Local groundphy:tbody = CreateBodyBox(100,100,100)
EntityParent (ground,groundphy)
ScaleEntity(ground,Vec3(100,100,100))
MoveEntity (groundphy, Vec3(0,-50,0))
SetBodyMass(groundphy, 0);
EntityType (groundphy, 1, 1);

Local crane:TEntity= CreateCube()
Local cranephy:tbody = CreateBodyBox(100,2,2)

EntityParent (crane,cranephy,0)
ScaleEntity(crane,Vec3(100,2,2))
MoveEntity (cranephy, Vec3(0,30,0))
SetBodyMass(cranephy, 0)
EntityType (cranephy, 1, 1)

Local cubePhy:tbody[10]
Local cube:tentity
Local joint:tjoint

For Local i:Int=1 To 10

cube= CreateCube()'boxes

cubePhy[i-1]= CreateBodyBox(1,1,1)

EntityParent (cube,cubePhy[i-1],1)
ScaleEntity(cube,Vec3(2,2,2))
SweptCollision (cubePhy[i-1], 1)
MoveEntity (cubePhy[i-1], Vec3(0,i*2-1+10,0))
SetBodyMass(cubePhy[i-1], 1)
EntityType (cubePhy[i-1], 1,0)

If i=10 
Joint:tjoint = CreateJointBall( cranephy,cubePhy[i-1], Vec3(0,29,0))
End If

If i>1 
Joint:tjoint = CreateJointBall( cubePhy[i-1],cubePhy[i-2], Vec3(0,i*2-2+10,0))
End If

Next

Collisions(1,1,1)' Important! Enable collision between bodys of Type 1


While Not KeyHit(KEY_ESCAPE)

If KeyHit(KEY_SPACE)
AddBodyForce(cubePhy[Rand(9)],Vec3(10000,0,10000),0)' apply force
End If


UpdateWorld(1)
SetBuffer(Buffer0)
RenderWorld()
SetBuffer(BackBuffer())
RenderLights(Buffer0)

DrawText ("Press SPACE to apply force to one of the boxes!",0,0)

Flip 1
Wend

[Canardia]

Yeah, but if you delete JointLibrary.dll then the joints don't hold together, and there is no error message either of a missing dll.

But this is kinda not really a bug, since it's obviously designed so that if JointLibrary.dll was not found, then joints just don't work.

It might be useful sometimes that way, instead of simply crashing the app.

[Josh]

Yep, that is true.

[AnniXa]

Ah cool thank you very much!

this explains all =)