Lines and trails

Contribution Depot
11

@kwando

There should be no wrapping, unless I messed up again (which I actually did when removing points, I fixed that now too, code above is updated). I gave it a shot with your texture, seems to work here:



[java]package mygame;



import com.jme3.app.SimpleApplication;

import com.jme3.input.KeyInput;

import com.jme3.input.MouseInput;

import com.jme3.input.controls.AnalogListener;

import com.jme3.input.controls.KeyTrigger;

import com.jme3.input.controls.MouseButtonTrigger;

import com.jme3.material.Material;

import com.jme3.material.RenderState.FaceCullMode;

import com.jme3.math.ColorRGBA;

import com.jme3.math.Vector3f;

import com.jme3.renderer.RenderManager;

import com.jme3.scene.Geometry;

import com.jme3.scene.Node;

import com.jme3.scene.shape.Box;



public class Main extends SimpleApplication {



Node geom;



public static void main(String[] args) {

Main app = new Main();

app.start();

}



@Override

public void simpleInitApp() {

Box b = new Box(Vector3f.ZERO, 1, 1, 1);

geom = new Node(); //new Geometry(“Box”, b);



Material mat = new Material(assetManager, “Common/MatDefs/Misc/Unshaded.j3md”);

mat.setColor(“Color”, ColorRGBA.Blue);

//geom.setMaterial(mat);

mat.setTexture(“ColorMap”,assetManager.loadTexture(“Textures/F3Fb0.png”));



Geometry trailGeometry = new Geometry();

LineControl line = new LineControl(new LineControl.Algo1CamDirBB(), true);

trailGeometry.addControl(line);

TrailControl trailControl = new TrailControl(line);

geom.addControl(trailControl);



//rootNode.attachChild(trail); // either attach the trail geometry node to the root…



trailGeometry.setIgnoreTransform(true); // or set ignore transform to true. this should be most useful when attaching nodes in the editor

Node test = new Node();

test.attachChild(trailGeometry);

test.setLocalTranslation(new Vector3f(0,2,0)); // without ignore transform this would offset the trail

rootNode.attachChild(test);



mat.getAdditionalRenderState().setFaceCullMode(FaceCullMode.Off);

trailGeometry.setMaterial(mat);



rootNode.attachChild(geom);

initKeys();

}



@Override

public void simpleUpdate(float tpf) {



}



@Override

public void simpleRender(RenderManager rm) {}



private void initKeys() {

inputManager.addMapping(“Left”, new KeyTrigger(KeyInput.KEY_J));

inputManager.addMapping(“Right”, new KeyTrigger(KeyInput.KEY_K));

inputManager.addMapping(“Rotate”, new KeyTrigger(KeyInput.KEY_SPACE),

new MouseButtonTrigger(MouseInput.BUTTON_LEFT));



inputManager.addListener(analogListener, new String[]{“Left”, “Right”, “Rotate”});



}





private AnalogListener analogListener = new AnalogListener() {

public void onAnalog(String name, float value, float tpf) {

if (name.equals(“Rotate”)) {

geom.rotate(0, valuespeed, 0);

}

if (name.equals(“Right”)) {

Vector3f v = geom.getLocalTranslation();

geom.setLocalTranslation(v.x + valuespeed5, v.y, v.z);

}

if (name.equals(“Left”)) {

Vector3f v = geom.getLocalTranslation();

geom.setLocalTranslation(v.x - valuespeed*5, v.y, v.z);

}

}

};

}[/java]



Screenshot:

E6pB5.png1276×720
http://i.imgur.com/E6pB5.png





And here’s a small attempt to explain the idea behind the texture coordinates’ computation:

http://i.imgur.com/jvMr7.png

As you can see texture coordinates range from zero to one, so yeah, there should be no wrapping.



However I added a getter for totalLength, so by pushing that into a shader and multiplying totalLength with the texcoord.x in that shader you can find out how long in your world units (meters?) your line is at that vertex/pixel if you need that for some reason.





@erlend_sh I will try and do that, unless it’s made part of the core anyway. I didn’t know if it was ok for me to spam the contribution center with small contributions like this, since I have a few other things planned too. Or should I make one big plugin with all my stuff in it?

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