}

> Hi everybody! :)

> I'm facing a problem that's really making me mad: i'm using a ProximitySensor
> to catch user viewpoint position and orientation, and using routes I move a
> box (that should be representing an hud) in front of the user camera...

> This trick is working if the user is not too much far from the "center" of
> the vrml world (coordinates 0, 0, 0)...but when he starts going away, let's
> say coordinates in order of 1.000.000, it all starts to flicker, jitter, and
> other strange behaviour... :(

> I need to let the user be able to go that far from the center of the vrml
> world beacause i'm using geo-vrml to let him navigate through some
> geo-referenced land representation, and the geovrml creates those nodes at
> location whose coordinates are in the order of 3-4.000.000, using vrml
> measure unit.

> Here you will find a page with two simple example of what I'm talking about:
> the vrml code is pretty the same, except for the "main" Transform node, whose
> translation field is set to 100, 100, 100 for the first one (that in fact is
> working correctly) and to 1.000.000, 1.000.000, 1.000.000 for the second, the
> one with the artifacts...

> http://snipurl.com/frxz

> Ah, btw, i'm using the last version of the cortona vrml viewer under
> windowsXP...

> Thank you! :)

> ps: if you mind, this is the vrml code...

> #VRML V2.0 utf8

> # Global objects
> Transform
> {
>    translation 100 100 100
>    # For the example with flickers, the translation is set to this:
>    # translation 1000000 1000000 1000000

>    children [

>            DEF SENSOR ProximitySensor {
>               size 10 10 10
>               center 0 0 10
>            }

>            # Real-World objects  <<<----
>            Transform {
>               children [
>                  DirectionalLight {
>                     ambientIntensity 0.8
>                  }
>                  Transform {
>                     translation 3 0 0
>                     children [
>                        Shape {
>                           appearance Appearance {
>                              material Material {
>                                 diffuseColor 0 0 1
>                              }
>                           }
>                           geometry Cone {}
>                        }
>                     ]
>                  }
>                  Shape {
>                     appearance Appearance {
>                        material Material {
>                           diffuseColor 0 1 0
>                        }
>                     }
>                     geometry Sphere {}
>                  }
>                  Transform {
>                     translation -3 0 0
>                     children [
>                        Shape {
>                           appearance Appearance {
>                              material Material {
>                                 diffuseColor 1 0 0
>                              }
>                           }
>                           geometry Box {}
>                        }
>                     ]
>                  }
>               ]
>            }

>            #HUD objects   <<<-----
>            DEF HUDVIEW Viewpoint {
>               description "HUD View"
>               position 0 0 10
>            }
>            DEF HUD Transform {
>               translation 0 0 10
>               children [
>                  Collision {
>                     collide FALSE
>                     children [
>                        DirectionalLight {
>                           ambientIntensity 0.8
>                        }
>                        Transform {
>                           translation 0 -0.075 -0.2
>                           children [
>                              Shape {
>                                 appearance Appearance {
>                                    material Material {
>                                       diffuseColor 1 0 1
>                                    }
>                                 }
>                                 geometry Box {
>                                    size 0.03 0.03 0.000000001
>                                 }
>                              }
>                           ]
>                        }
>                     ]
>                  }
>               ]
>            }
>    ]
> }

> # Routes to bind camera to hud
> ROUTE SENSOR.orientation_changed TO HUD.set_rotation
> ROUTE SENSOR.position_changed TO HUD.set_translation
> ROUTE SENSOR.position_changed TO SENSOR.set_center

> Hello,

> You could use a HUD or a Layer2D/Layer3D extension node, but it's no
> more pure VRML ...

> I had the same problem when I tried to put an object very very close to
> the "avatar" ...

> O.L. ha scritto:
>> Hello,

>> You could use a HUD or a Layer2D/Layer3D extension node, but it's no more
>> pure VRML ...

>> I had the same problem when I tried to put an object very very close to the
>> "avatar" ...

> Thank you for the quick answer! :)
> I don't mind if it's not pure VRML, as long as it solve this crazy problem...
> ;)
> I'll take a look to this extension nodes...just a question: are these working
> with every VRML player ?
> Or are extension implemented only in some viewer ?

> In the mean time I've discovered that it should *also* be a problem that
> deals with the ratio between the dimension of the objects in a scene and the
> distance of these objects from the world center.
> In fact, if you try to add a "scale" field to the main Translation node, and
> set it to let's say 1000, 1000, 1000 the flicker of the hud and of the
> objects will be almost null...

> I'll let you know as soon as I discover something else...thanks again for the
> help! :)

bboy wrote:
> Hi everybody! :)

> I'm facing a problem that's really making me mad: i'm using a
> ProximitySensor to catch user viewpoint position and orientation, and
> using routes I move a box (that should be representing an hud) in front
> of the user camera...

> This trick is working if the user is not too much far from the "center"
> of the vrml world (coordinates 0, 0, 0)...but when he starts going away,
> let's say coordinates in order of 1.000.000, it all starts to flicker,
> jitter, and other strange behaviour... :(

> I need to let the user be able to go that far from the center of the
> vrml world beacause i'm using geo-vrml to let him navigate through some
> geo-referenced land representation, and the geovrml creates those nodes
> at location whose coordinates are in the order of 3-4.000.000, using
> vrml measure unit.

> Here you will find a page with two simple example of what I'm talking
> about: the vrml code is pretty the same, except for the "main" Transform
> node, whose translation field is set to 100, 100, 100 for the first one
> (that in fact is working correctly) and to 1.000.000, 1.000.000,
> 1.000.000 for the second, the one with the artifacts...

> http://snipurl.com/frxz

> Ah, btw, i'm using the last version of the cortona vrml viewer under
> windowsXP...

> Thank you! :)

> ps: if you mind, this is the vrml code...

> #VRML V2.0 utf8

> # Global objects
> Transform
> {
>    translation 100 100 100
>    # For the example with flickers, the translation is set to this:
>    # translation 1000000 1000000 1000000

>    children [

>            DEF SENSOR ProximitySensor {
>               size 10 10 10
>               center 0 0 10
>            }

>            # Real-World objects  <<<----
>            Transform {
>               children [
>                  DirectionalLight {
>                     ambientIntensity 0.8
>                  }
>                  Transform {
>                     translation 3 0 0
>                     children [
>                        Shape {
>                           appearance Appearance {
>                              material Material {
>                                 diffuseColor 0 0 1
>                              }
>                           }
>                           geometry Cone {}
>                        }
>                     ]
>                  }
>                  Shape {
>                     appearance Appearance {
>                        material Material {
>                           diffuseColor 0 1 0
>                        }
>                     }
>                     geometry Sphere {}
>                  }
>                  Transform {
>                     translation -3 0 0
>                     children [
>                        Shape {
>                           appearance Appearance {
>                              material Material {
>                                 diffuseColor 1 0 0
>                              }
>                           }
>                           geometry Box {}
>                        }
>                     ]
>                  }
>               ]
>            }

>            #HUD objects   <<<-----
>            DEF HUDVIEW Viewpoint {
>               description "HUD View"
>               position 0 0 10
>            }
>            DEF HUD Transform {
>               translation 0 0 10
>               children [
>                  Collision {
>                     collide FALSE
>                     children [
>                        DirectionalLight {
>                           ambientIntensity 0.8
>                        }
>                        Transform {
>                           translation 0 -0.075 -0.2
>                           children [
>                              Shape {
>                                 appearance Appearance {
>                                    material Material {
>                                       diffuseColor 1 0 1
>                                    }
>                                 }
>                                 geometry Box {
>                                    size 0.03 0.03 0.000000001
>                                 }
>                              }
>                           ]
>                        }
>                     ]
>                  }
>               ]
>            }
>    ]
> }

> # Routes to bind camera to hud
> ROUTE SENSOR.orientation_changed TO HUD.set_rotation
> ROUTE SENSOR.position_changed TO HUD.set_translation
> ROUTE SENSOR.position_changed TO SENSOR.set_center