java - libGdx with Box2D loader bicycle wheel joint -

i'm using libgdx framework box2d physics editor. can't figure out wrong. why can't joint correctly wheels chassis. wheels not holding chassis. sorry mistake. here pic. get:

<img src='http://s4.postimg.org/a0d6ujpjt/test.jpg' border='0' alt="test" />

code application:

package com.ernestyno.test;  import com.ernestyno.text.bodyeditorloader.bodyeditorloader; import com.badlogic.gdx.gdx; import com.badlogic.gdx.inputadapter; import com.badlogic.gdx.graphics.texture; import com.badlogic.gdx.graphics.texture.texturefilter; import com.badlogic.gdx.graphics.g2d.sprite; import com.badlogic.gdx.graphics.g2d.spritebatch; import com.badlogic.gdx.math.mathutils; import com.badlogic.gdx.math.vector2; import com.badlogic.gdx.physics.box2d.body; import com.badlogic.gdx.physics.box2d.bodydef; import com.badlogic.gdx.physics.box2d.circleshape; import com.badlogic.gdx.physics.box2d.bodydef.bodytype; import com.badlogic.gdx.physics.box2d.fixturedef; import com.badlogic.gdx.physics.box2d.world; import com.badlogic.gdx.physics.box2d.joints.wheeljoint; import com.badlogic.gdx.physics.box2d.joints.wheeljointdef;  public class dviratis extends inputadapter { private world world; private float x, y, width;  private body dviracioremasbody, kairysratasbody, desinysratasbody; private wheeljoint kairysratasjoint, desinysratasjoint; private vector2 dviracioremasorigin, ratasorigin; private sprite remassprite, kairysratassprite, desinysratassprite; private texture remastexture, ratastexture;  //fixtures private fixturedef dviracioremasfixture, dviracioratofixture;  private float //remas fixture duomenys remas_density       = 5f, remas_friction      = .4f, remas_restitution   = .3f,  //ratu fixture duomenys ratas_density       = remas_density * 1.5f, ratas_friction      = 50f, ratas_restitution   = .4f;  private string  body_editor_file        = "json/dviratis.json", body_editor_remas_name  = "dviracioremas", body_editor_ratas_name  = "ratas";  public dviratis(world world, float x, float y, float width) {     this.world = world;     this.x = x;     this.y = y;     this.width = width;      this.setfixture();     this.setsprite();     this.setbody(); }  public void setfixture() {     this.dviracioremasfixture               = new fixturedef();     this.dviracioratofixture                = new fixturedef();      this.dviracioremasfixture.density       = this.remas_density;     this.dviracioremasfixture.friction      = this.remas_friction;     this.dviracioremasfixture.restitution   = this.remas_restitution;      this.dviracioratofixture.density        = this.ratas_density;     this.dviracioratofixture.friction       = this.ratas_friction;     this.dviracioratofixture.restitution    = this.ratas_restitution; }  public void setsprite() {     this.remastexture = new texture(gdx.files.internal("json/dviracio_remas.png"));     this.remastexture.setfilter(texturefilter.linear, texturefilter.linear);     this.remassprite = new sprite(this.remastexture);     this.remassprite.setsize(this.width, this.width * this.remassprite.getheight() / this.remassprite.getwidth());      this.ratastexture = new texture(gdx.files.internal("json/dviracio_ratas.png"));     this.ratastexture.setfilter(texturefilter.linear, texturefilter.linear);     this.desinysratassprite = new sprite(this.ratastexture);     this.desinysratassprite.setsize(this.width / 3, this.width / 3);      this.kairysratassprite = new sprite(this.ratastexture);     this.kairysratassprite.setsize(this.width / 3, this.width / 3); }  public void setbody() {     bodydef bodydef = new bodydef();     bodyeditorloader loader = new bodyeditorloader(gdx.files.internal(this.body_editor_file));      bodydef.type = bodytype.dynamicbody;     bodydef.position.set(this.x, this.y);      this.dviracioremasbody = this.world.createbody(bodydef);     loader.attachfixture(this.dviracioremasbody, this.body_editor_remas_name, this.dviracioremasfixture, this.width);     this.dviracioremasorigin = loader.getorigin(this.body_editor_remas_name, this.width).cpy();      this.desinysratasbody = this.world.createbody(bodydef);     loader.attachfixture(this.desinysratasbody, this.body_editor_ratas_name, this.dviracioratofixture, this.width / 3);      this.kairysratasbody = this.world.createbody(bodydef);     loader.attachfixture(this.kairysratasbody, this.body_editor_ratas_name, this.dviracioratofixture, this.width / 3);      this.ratasorigin = loader.getorigin(this.body_editor_ratas_name, this.width).cpy();      //masinos kairio rato susiejimas prie masinos kuno     wheeljointdef axisdef = new wheeljointdef();     axisdef.bodya = this.dviracioremasbody;     axisdef.bodyb = this.desinysratasbody;     //nuo centro ratu susiejimo atittraukimas x ir y pozicija     axisdef.localanchora.set(0.73f, -0.45f);     axisdef.localanchorb.set(0f, 0f);     axisdef.localaxisa.set(vector2.y); //vector2.y = new vector2(0, 1); - ratu amortizacija y asije, o ne x asije      this.desinysratasjoint = (wheeljoint) world.createjoint(axisdef);      axisdef.bodyb = this.kairysratasbody;     axisdef.localanchora.set(-1f, -0.45f);     axisdef.frequencyhz = this.dviracioremasfixture.density; //amortizatoriaus galia     axisdef.maxmotortorque = this.dviracioremasfixture.density * 10; //variklio galia      this.kairysratasjoint = (wheeljoint) world.createjoint(axisdef); }  public void render() {     vector2 pozicija = this.dviracioremasbody.getposition().sub(this.dviracioremasorigin);      this.remassprite.setposition(pozicija.x, pozicija.y);     this.remassprite.setorigin(this.dviracioremasorigin.x, this.dviracioremasorigin.y);     this.remassprite.setrotation(this.dviracioremasbody.getangle() * mathutils.radianstodegrees);      pozicija = this.desinysratasbody.getposition().sub(this.ratasorigin);      this.desinysratassprite.setposition(pozicija.x, pozicija.y);     this.desinysratassprite.setorigin(this.ratasorigin.x, this.ratasorigin.y);     this.desinysratassprite.setrotation(this.desinysratasbody.getangle() * mathutils.radianstodegrees);      pozicija = this.kairysratasbody.getposition().sub(this.ratasorigin);      this.kairysratassprite.setposition(pozicija.x, pozicija.y);     this.kairysratassprite.setorigin(this.ratasorigin.x, this.ratasorigin.y);     this.kairysratassprite.setrotation(this.kairysratasbody.getangle() * mathutils.radianstodegrees); }  public void draw(spritebatch batch) {     this.remassprite.draw(batch);     this.desinysratassprite.draw(batch);     this.kairysratassprite.draw(batch); }  public body getremas() {     return dviracioremasbody; }  public body getdviracioremasbody() {     return dviracioremasbody; } } 

huh... found wrong. program "physics-body-editor" generate's wrong circle center position in .json file. coordinates cx , cy. replaced bodyeditorloader.java file. created attachfixture() method allows describe circle coordinates.

instead of circles:

loader.attachfixture(this.desinysratasbody, this.body_editor_ratas_name, this.dviracioratofixture, this.width / 3); 

use:

loader.attachfixture(this.desinysratasbody, this.body_editor_ratas_name, this.dviracioratofixture, this.width / 3, new vector2(0,0)); 

if want can download bodyeditorloader file

now wheels @ correct position. result image