[Todd]

Hey again,

 

I am working on my animation and now i can see all the images and sprites are working fine, but now I am having trouble getting physicsWorld to work and show.

 

This is my code for the player.qml which I want a BoxCollider for,

 

import Felgo 3.0
import QtQuick 2.0


EntityBase {
id: player
width:30
height: 60
    entityType: "player"

    property alias collider: collider
    property alias horizontalVelocity: collider.linearVelocity.x
PhysicsWorld {
debugDrawVisible: true
}
    AnimatedSprite {
        id: walk
        width: 100
        height: 200
        anchors.centerIn: parent
        source: "../assets/WalkingManSpriteSheet.png"
        frameCount: 8
        frameRate: 6
        frameWidth: 41
        frameHeight:49
        loops: 100
        x: 200
        y: 50

}
    BoxCollider {
      id: collider
      height: player.height
      width: player.width

      // this collider must be dynamic because we are moving it by applying forces and impulses
      bodyType: Body.Dynamic // this is the default value but I wanted to mention it ;)
      fixedRotation: true // we are running, not rolling...
      bullet: true // for super accurate collision detection, use this sparingly, because it's quite performance greedy
      sleepingAllowed: false
      // apply the horizontal value of the TwoAxisController as force to move the player left and right
      force: Qt.point(controller.xAxis*170*32,0)
      // limit the horizontal velocity
      onLinearVelocityChanged: {
        if(linearVelocity.x > 170) linearVelocity.x = 170
        if(linearVelocity.x < -170) linearVelocity.x = -170
      }
    }
}

 

No errors in the code, I just cannot see any colliders and they are not registering… thanks for all your help!

[AlexFelgo Team]

Hi Todd,

please follow this tutorial to learn the basics of physics and the entity concept. The PhysicsWorld belongs in your Scene or any other container of your game world, and the entities only need colliders.

Also have a look at the documentation if you are not sure how to use a component, we have a lot of examples in there as well, like this one: https://felgo.com/doc/vplay-physicsworld/

Cheers,
Alex

[Todd]

Hey, thanks for the reply.

 

I went through and figured it out, I can now see the box collider when running, but for some reason the box collider does not have my cannon image inside of it and im  not sure why, i have it the box collider anchored inside the cannon sprite image but it places the image outside of it. This is what I have..

 

import QtQuick 2.7
import QtQuick.Window 2.2
import Felgo 3.0

GameWindow {
id:gameWindow
width: Screen.width
height: Screen.height



Item {
width:Screen.width
height:Screen.height-10
focus: true


Keys.onPressed: {

if (event.key===Qt.Key_Right){
event.accepted = true;
walk.x=(walk.x) +7

}
if (event.key===Qt.Key_Left){
event.accepted = true;
walk.x=(walk.x) -7
}
}
Flickable{
width:Screen.width
height:Screen.height
contentHeight: Screen.height *4
contentWidth: Screen.width
interactive: true
boundsBehavior: Flickable.StopAtBounds

Image{
id: box
anchors.fill: parent
source: "../assets/rect.png"
sourceSize.width: Screen.width
sourceSize.height: Screen.height*4
}






AnimatedSprite {
    id: walk
    width: 100
    height: 200

    source: "../assets/WalkingManSpriteSheet.png"
    frameCount: 8
    frameRate: 6
    frameWidth: 41
    frameHeight:49
    loops: 100
    x: 200
    y: 50
}






Image{
id:twitter
source: "../assets/twitter.png"
x:500
y:200
}

PhysicsWorld
{
gravity.y: 9.81
debugDrawVisible: true
}

Scene {
id:scene



EntityManager {
     id: entityManager
     entityContainer: scene// this property is needed if you want to dynamically create entities at runtime, if you don't do this, you can remove it.
   }

EntityBase {
entityId: cannonbox
    entityType: "box"

AnimatedSprite {
    id: cannon
    width: 150
    height: 212
anchors.fill: cannon
    source: "../assets/cannon.png"
    frameCount: 12
    frameRate: 8
    frameWidth: 128
    frameHeight:155
    loops: 100

}

BoxCollider {
    anchors.fill: cannon
    collisionTestingOnlyMode: true
}

}
}

}
}
}

 

Do you know why the box collider is not anchoring with the cannon image?

[Todd]

Quick update…

 

So I was able to get the box collider to fit around the cannon image by just setting x and y cordinates, but no matter what I do I cannot just get an anchors.fill to work on it…. would be helpful to know why not for once I start moving the images around

[Marcin]

Hi Todd,
It is hard to replicate the issue because I don’t have the images you use in the code.
If you can provide some code snippet with some files which I can just test it, would be great.
Probably would figure it out quickly what is wrong.

If not, there is one thing.
Maybe it is not the issue but I saw something odd in the example you provided.
So like you said, the collider is anchored inside the sprite animation(anchors.fill: cannon).
But the animation is centered inside itself.
In the sprite animation bit:

anchors.fill: cannon

Bu the animation sprite is named cannon.
Didn’t you want to use there:

anchors.fill: cannonbox

So basically center the animation sprite in the entity?

What I would also propose is to set entity width and height.
The same as the sprite animation(or the frame etc. can’t tell without images and do proper test case replication).
Hopefully this will improve things.

[Todd]

Hey Marcin, thanks for the reply.

Been on vacation so now I am finally looking at this again. So I tried doing what you said with centering the animation sprite inside the entity, but it will still set the box collider outside of the cannon. What can i do to easily send you the files you need to test? Also note that for some reason when I place the cannon sprite image in the scene it will not hug the upper left corner as it should without and coordinates set for it…

 

Thanks!

[Todd]

Hey so i messed around with it some more…

 

I went ahead and added a box collider around the player walking, except it will not anchor around it and when i move the player the box collider follows behind….. but it (the box collider) will not ever actually be around the player

 

this is the code..

import QtQuick 2.7
import QtQuick.Window 2.2
import Felgo 3.0

GameWindow {
id:gameWindow
width: Screen.width
height: Screen.height



Item {
width:Screen.width
height:Screen.height-10
focus: true


Keys.onPressed: {

if (event.key===Qt.Key_Right){
event.accepted = true;
walk.x=(walk.x) +7

}
if (event.key===Qt.Key_Left){
event.accepted = true;
walk.x=(walk.x) -7
}
}
Flickable{
width:Screen.width
height:Screen.height
contentHeight: Screen.height *4
contentWidth: Screen.width
interactive: true
boundsBehavior: Flickable.StopAtBounds

Image{
id: box
anchors.fill: parent
source: "../assets/rect.png"
sourceSize.width: Screen.width
sourceSize.height: Screen.height*4
}












Image{
id:twitter
source: "../assets/twitter.png"
x:500
y:200
}

PhysicsWorld
{
gravity.y: 9.81
debugDrawVisible: true
}

Scene {
id:scene



EntityManager {
     id: entityManager
     entityContainer: scene// this property is needed if you want to dynamically create entities at runtime, if you don't do this, you can remove it.
   }

EntityBase {
id: cannonbox
    entityId:  "cannonbox"
    entityType: "box"
    width: 125
    height: 190

AnimatedSprite {
    id: cannon
    anchors.fill: cannonbox
    width: 150
    height: 212

    source: "../assets/cannon.png"
    frameCount: 12
    frameRate: 8
    frameWidth: 128
    frameHeight:155
    loops: 100

}




BoxCollider {
id:box1
    anchors.fill: parent
    collisionTestingOnlyMode: true
}



}
EntityBase {
    id: player
        entityId:  "player"
        entityType: "box"
        width: 70
        height: 125

        AnimatedSprite {
            id: walk
            width: 35
            height: 90

            source: "../assets/WalkingManSpriteSheet.png"
            frameCount: 8
            frameRate: 6
            frameWidth: 41
            frameHeight:49
            loops: 100
            x: 80
            y: 50

        }
        BoxCollider {
        id:box2
            anchors.fill: walk
            bodyType: Body.Dynamic
            collisionTestingOnlyMode: true
        }
}


}
}
}
}

 

 

why is it doing this 🙁

[GüntherFelgo Team]

Hi!

The reason is as follows:

The collider, which you can see when activating debugDrawVisible of PhysicsWorld, is actually placed within the PhysicsWorld and NOT within the entity.
The collider simply uses the size and position configured within the Entity. So when e.g. the size and position changes, the actual collider within the PhysicsWorld also moves along.

This means the following conditions are required for the colliders in PhysicsWorld to match with the Entity:

• The entities themselves should use in the same coordinate system as the PhysicsWorld. If the position of the entities is e.g. influenced by parent items, but the PhysicsWorld is not, the position of the collider won’t match.
• If your Sprite Images apply a position offset within the entity, but the collider will match the entity, but the sprite image within the entity will not match.

This is a short outtake of your code sample with fixed entity and collider settings:

import QtQuick 2.7
import QtQuick.Window 2.2
import Felgo 3.0

GameWindow {
  id:gameWindow
  width: Screen.width
  height: Screen.height

  Item {
    width:Screen.width
    height:Screen.height-10
    focus: true


    Keys.onPressed: {

      if (event.key===Qt.Key_Right){
        event.accepted = true;
        walk.x=(walk.x) +7

      }
      if (event.key===Qt.Key_Left){
        event.accepted = true;
        walk.x=(walk.x) -7
      }
    }



    Scene {
      id:scene

      PhysicsWorld
      {
        gravity.y: 9.81
        debugDrawVisible: true
      }

      EntityManager {
        id: entityManager
        entityContainer: scene// this property is needed if you want to dynamically create entities at runtime, if you don't do this, you can remove it.
      }

      EntityBase {
        id: cannonbox
        entityId:  "cannonbox"
        entityType: "box"
        width: 125
        height: 190

        Rectangle {
          id: cannon
          anchors.fill: cannonbox
          color: "blue"
        }

        BoxCollider {
          id:box1
          anchors.fill: parent
          collisionTestingOnlyMode: true
        }
      }

      EntityBase {
        id: player
        entityId:  "player"
        entityType: "box"
        width: 70
        height: 125
        x: 80
        y: 50

        Rectangle {
          id: walk
          width: 35
          height: 90
          color: "green"
        }

        BoxCollider {
          id:box2
          anchors.fill: walk
          bodyType: Body.Dynamic
          collisionTestingOnlyMode: true
        }
      }
    }

  }
}

 

Best,
Günther

[Todd]

Gunther,

 

Thanks so much! You are awesome!