3d tiles under terrain and single layer pickering

pol_carrera_balsells · May 23, 2018, 8:09am

1. A concise explanation of the problem you’re experiencing.

Hello everyone. I am new to Cesium and during the realization of my app I had 2 problems.
First, my app has a 3dTiles layer with 3d buildings and a geojsondatasoure layer with the scope of the project. I just want to get information by picking the buildings, but if the 2 layers are active I can not; the geojson datasource stays on top of me and does not let me select the buildings (photo 1). What I can do?
The second problem comes with 3d buildings and their attachment to the model of elevations. With the ellipsoid there is no problem, the problem comes with cesium world terrain. They are sunk under the ground. I have tried with heightOffset but some continue sunk or overraised. Is there any way to individually place each building on the ground?
Thank you very much,
Pol

2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.

Hello World! @import url(../Build/Cesium/Widgets/widgets.css); html, body, #cesiumContainer { width: 100%; height: 100%; margin: 0; padding: 0; overflow: hidden; } #toolbar { background: rgba(42, 42, 42, 0.8); padding: 4px; border-radius: 4px; } #toolbar input { vertical-align: middle; padding-top: 2px; padding-bottom: 2px; } #toolbar .header { font-weight: bold; } h2 { color: black; } p { color: black; }

Àmbit

3dBuildings

unterzwerg1 · May 24, 2018, 9:37am

I have a similar problem; but instead of 3DTile I am using a simpe box.
On WGS84 Ellipsoid the box is clipped to the ground; when on WorldTerrain the box is partwise beneath the surface.
You can confirm this:
- setting to WGS84-Ellipsoid
- Click "onEllipsoid"
--> the box is clipped to ground
- click "magnitude 10"
- click "up"
--> the box is "flying" over the surface

- setting to Cesium World Terrain
- click "onTerrain"
--> part of the box is beneath surface:
- click "magnitude 10"
- click "up"
--> the box is comimg more up but still partwise under surface

This is the code:
var viewer = new Cesium.Viewer('cesiumContainer');
var CC3 = Cesium.Cartesian3;
var magnitude = 1;

var box_height = 30;

var thebox = viewer.entities.add({
    name : 'building',
    position: Cesium.Cartesian3.fromDegrees(-90.1922703175, 38.6286636758, box_height/2),
    box : {
        dimensions : new Cesium.Cartesian3(40, 30, box_height),
        material : Cesium.Color.RED,
        outline : true,
        outlineColor : Cesium.Color.BLACK
    }
});
viewer.zoomTo(viewer.entities);

//var terrainProvider = new Cesium.CesiumTerrainProvider({
// url : '//assets.agi.com/stk-terrain/world',
requestVertexNormals : true
//});

var terrainProvider = Cesium.createWorldTerrain();

function setOnTerrain()
{
    var mycarte = thebox._position._value;
    thebox.position = mycarte;
    var mycarto = new Cesium.Cartographic();
    mycarto = viewer.scene.globe.ellipsoid.cartesianToCartographic(thebox._position._value);
    //takes the terrain, a precision value and the point of interest
    Cesium.sampleTerrain(terrainProvider, 11, [mycarto]).then(function(){
        console.log("setting to terrain height: "+(mycarto.height));
        mycarto.height += box_height/2;
        thebox.position = viewer.scene.globe.ellipsoid.cartographicToCartesian(mycarto);
    });
}

function setOnEllipsoid()
{
    var mycarte = thebox._position._value;
    thebox.position = mycarte;
    var mycarto = new Cesium.Cartographic();
    mycarto = viewer.scene.globe.ellipsoid.cartesianToCartographic(thebox._position._value);
    mycarto.height = box_height/2;
    console.log("setting to ellipsoid height: "+(mycarto.height));
    thebox.position = viewer.scene.globe.ellipsoid.cartographicToCartesian(mycarto);
}

Sandcastle.addToolbarButton('magnitude 1', function()
{magnitude=1;});
Sandcastle.addToolbarButton('magnitude 10', function()
{magnitude=10;});

Sandcastle.addToolbarButton('east', function()
{move(magnitude,getVector("east"));});
Sandcastle.addToolbarButton('west', function()
{move(-magnitude,getVector("east"));});
Sandcastle.addToolbarButton('north', function()
{move(magnitude,getVector("north"));});
Sandcastle.addToolbarButton('south', function()
{move(-magnitude,getVector("north"));});
Sandcastle.addToolbarButton('up', function()
{move(magnitude,getVector("up"));});
Sandcastle.addToolbarButton('down', function()
{move(-magnitude,getVector("up"));});
Sandcastle.addToolbarButton('onTerrain', function()
{setOnTerrain();});
Sandcastle.addToolbarButton('onEllipsoid', function()
{setOnEllipsoid();});

What is wrong?

Gabby_Getz · May 25, 2018, 1:34pm

Hi all,

Pol, I don’t think you attached that image, seeing it would help!

unterzwerg, I don’t understand what problem you are having. Do you not want the box to be below terrain at all?

Thanks,

Gabby

pol_carrera_balsells · May 25, 2018, 2:19pm

Hello Gabby,

 I have not remembered to put the images as an example, I'm sorry. In this email I attached 4 images where it is clear how the buildings look in WSG84 and in Cesium World Terrain as well as the problem that I have with the picking when having selected both the buildings and the scope of the project.

Thank you very much,

Pol

sean_lilley · May 27, 2018, 3:48pm

unterzwerg - try using sampleTerrainMostDetailed. The box lines up perfectly after doing that.

sean_lilley · May 27, 2018, 6:17pm

Hey Pol,

For the issue where the GeoJSON is preventing picking buildings, you can use drillPick to get the building that’s underneath the GeoJSON. Also in Cesium 1.46 the GeoJSON will no longer drape over 3D Tiles by default so this may not be a problem once you upgrade.

For the second issue, Cesium doesn’t support clamping 3D Tiles to terrain. The most common workaround is to adjust the height of the tileset like in this Sancastle demo. You can determine a good height to use by calling sampleTerrainMostDetailed.

unterzwerg1 · May 28, 2018, 9:39am

Hello Gabby,
thanks for answering
I want the box to be ABOVE the terrain at all; the box should be positioned on the ground.

unterzwerg1 · May 28, 2018, 9:50am

Thank you!!!
I suppose that works!

pol_carrera_balsells · May 29, 2018, 8:43am

Hi, Sean. Thank you for answering so quickly. I have been working on the heights with the sampleTerrainMostDetailed to adjust the height of the buildings in the terrain model through a button.

sean_lilley · May 29, 2018, 11:58pm

There isn’t a way to adjust individual buildings right now. The next closest thing is setting the transform of individual tiles. Just be careful though because the transforms are applied hierarchically, so the parent tile transform affects the child tile transform.

pol_carrera_balsells · May 31, 2018, 7:46am

Thanks Sean.

I’m gonna left the buildings on the WGS84 Ellipsoid. Transformations of individual tiles sounds too complicated for me.

Cheers,

Pol

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3d tiles under terrain and single layer pickering

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