Attach camera to entity / follow entity

Comments

• dave1707 Mod

  July 2019 Posts: 7,956

  @threads I don't know if this will help. I'm not adding the camera like you show above, but I'm moving the camera around the Craft scene. See the code in the link below.

  https://codea.io/talk/discussion/8932/starter-game-22#latest
  
• dave1707 Mod

  July 2019 Posts: 7,956

  @threads I haven't been able to change the camera position on an entity, but maybe you can create a second entity attached to the first and just above it and attach the camera to the second entity. I haven't tried it yet myself.
• dave1707 Mod

  July 2019 edited July 2019 Posts: 7,956

  @threads I took one of my projects and modified it to attach a camera to one of the objects. Tap the attach parameter to attach or release the camera. I still haven't been able to alter the camera position relative to the object.

  PS. Added code to allow the attached camera to be rotated using the parameter sliders.

  function setup()
      opac=.3
      parameter.action("attach",attach)
      parameter.integer("angX",0,360,0)
      parameter.integer("angY",0,360,0)
      parameter.integer("angZ",0,360,0)
      size=.2
      fill(255)
      scene = craft.scene()
      skyMaterial=scene.sky.material
      skyMaterial.sky=color(0, 62, 255, 255)
      skyMaterial.horizon=color(99, 255, 0, 255)
      scene.sun.rotation=quat.eulerAngles(20,45,-30)
      createObjects()
      v=scene.camera:add(OrbitViewer, vec3(0,0,0), 30, 0, 200)
      v.rx=30
      v.ry=30
  end
  
  function attach()
      if not aa then
          aa=scene:entity()
          s1=aa:add(craft.rigidbody,DYNAMIC)
          s1.linearVelocity=vec3(2,2,2)
          s1.restitution=1
          s1.friction=0
          aa.position=vec3(0,0,0)
          aa:add(craft.shape.sphere,size)
          aa.model = craft.model.icosphere(size,2)
          aa.material = craft.material("Materials:Specular")
          aa.material.diffuse=color(255)        
          c=aa:add(craft.camera, 120, 0, 10, false)
      else
          c=nil
          aa:destroy()
          aa=nil
      end
  end
  
  function createObjects()
      for z=1,100 do
          a=scene:entity()
          s1=a:add(craft.rigidbody,DYNAMIC)
          s1.linearVelocity=vec3(2,2,2)
          s1.restitution=1
          s1.friction=0
          a.position=vec3(0,0,0)
          a:add(craft.shape.sphere,size)
          a.model = craft.model.icosphere(size,2)
          a.material = craft.material("Materials:Specular")
          a.material.diffuse=color(255,0,0)
      end    
  
      wall1=createWall(1,vec3(-5,0,0),vec3(.1,10,10),vec3(.1,10,10),"Blocks:Error")
      wall2=createWall(1,vec3(5,0,0),vec3(.1,10,10),vec3(.1,10,10),"Blocks:Dirt Sand")    
      wall3=createWall(1,vec3(0,-5,0),vec3(10,.1,10),vec3(10,.1,10),"Blocks:Cotton Blue")    
      wall4=createWall(1,vec3(0,0,5),vec3(10,10,.1),vec3(10,10,.1),"Blocks:Cactus Side")    
      wall5=createWall(1,vec3(0,0,-5),vec3(10,10,.1),vec3(10,10,.1),"Blocks:Brick Red")
      wall6=createWall(1,vec3(0,5,0),vec3(10,.1,10),vec3(10,.1,10),"Blocks:Brick Grey")
  end
  
  function createWall(rest,pos,a,mod,map)
      local ww=scene:entity()
      local w=ww:add(craft.rigidbody,STATIC)
      w.restitution=rest
      ww.position=pos
      ww:add(craft.shape.box,a)
      ww.model = craft.model.cube(mod)
      ww.material = craft.material("Materials:Standard")
      ww.material.map = readImage(map)
      ww.material.blendMode = NORMAL
      return ww
  end
  
  function draw()
      update(DeltaTime)
      scene:draw()    
      text("Move the slider to change opacity",WIDTH/2,HEIGHT-50)
      text("Drag your finger on the screen to rotate the cube",WIDTH/2,HEIGHT-100)
  end
  
  function update(dt)
      scene:update(dt)
      wall1.material.opacity=opac
      wall2.material.opacity=opac
      wall3.material.opacity=opac
      wall4.material.opacity=opac
      wall5.material.opacity=opac
      wall6.material.opacity=opac
      if c then
          c.entity.eulerAngles=vec3(angX,angY,angZ)
      end
  end
  
• threads

  July 2019 Posts: 24

  Thanks a lot for your time and answer @dave1707
  
  Yes, i managed to attach the camera to an entity (I was confused before, the camera is a component, not an entity) but I didn’t find a way to move it relatively from the entity itself, so I ended up moving my camera independently in my update/draw function
• dave1707 Mod

  July 2019 edited July 2019 Posts: 7,956

  @threads Here's an example of attaching the camera to an entity and move everything around the scene.

  PS. I modified the code to use the tilt of the iPad to change the direction traveled.

  displayMode(FULLSCREEN)
  
  function setup()
      bx,bz=500,500   -- initial block position
      vel=.2          -- velocity
      dir=45
  
      scene = craft.scene()
  
      ground=scene:entity()
      ground.model = craft.model.cube(vec3(10000,1,10000))
      ground.position=vec3(0,-10,0)
      ground.material = craft.material("Materials:Standard")
      ground.material.map = readImage("Surfaces:Desert Cliff Normal")
      ground.material.offsetRepeat=vec4(0,0,50,50)
  
      block = scene:entity()
      block.model = craft.model.cube(vec3(4,.5,2))
      block.material = craft.material("Materials:Standard")
      block.material.map = readImage("Blocks:Trunk White Top")
      block.position=vec3(gx,0,gp)
  
      cam = scene:entity()
      cam.model = craft.model.cube(vec3(.2,.2,.2))
      cam.material = craft.material("Materials:Specular")
      cam.material.map = readImage("Blocks:Brick Grey")
      cam.position=vec3(0,6,6)
  
      cam.parent=block    -- attach camera to block
      c=cam:add(craft.camera, 120, .1, 1000, false) -- set camera values
      c.entity.eulerAngles=vec3(0,180,0)  -- set camera pointing direction
  end
  
  function update(dt)
      scene:update(dt)
      block.eulerAngles = vec3(0,dir,0)
      bx=bx-vel*math.sin(math.rad(dir))   -- calculate x value
      bz=bz-vel*math.cos(math.rad(dir))   -- calculate z value
      block.position=vec3(bx,0,bz)        -- update block x,z position   
      c.entity.eulerAngles=vec3(0,180,-Gravity.x*50)  -- set camera pointing direction
  end
  
  function draw()
      update(DeltaTime)
      scene:draw()    
      dir=dir-Gravity.x*3
  end
  
• threads

  July 2019 edited July 2019 Posts: 24

  Haha awesome @dave1707 ! Thank you !!
  
  Edit : this should be a tutorial or a default project ! (Minus the cube attached to the cam entity, which is not necessary, and would make the code even shorter)