How do I clip an entity or geometry against underside of terrain
2
I am using the Cesium.Globe clipping planes to extract a square geographic section. But one problem is that terrain back-faces are not rendered which makes it look weird when the user selects a shallow viewing angle.
I thought one way to hide this was to render the "soil" as a box or wall under the terrain, but I would need the top of the box or wall to confirm to the terrain geometry (red line).
I figure I can achieve this by using a WallGeometry around the culled terrain instead of a box, and set the height of each section based on the result of a sampleTerrain call.
But I was wondering if Cesium doesn't provide an easier and cleaner way to do this. (Like perhaps some Boolean union function or something)
Cesium Sandcastle link
var viewer = new Cesium.Viewer('cesiumContainer', {
skyAtmosphere: false,
shouldAnimate : true,
terrainProvider: Cesium.createWorldTerrain()
});
var globe = viewer.scene.globe;
var position = Cesium.Cartographic.toCartesian(new Cesium.Cartographic.fromDegrees(-113.2665534, 36.0939345, 100));
var distance = 3000.0;
globe.clippingPlanes = new Cesium.ClippingPlaneCollection({
modelMatrix : Cesium.Transforms.eastNorthUpToFixedFrame(position),
planes : [
new Cesium.ClippingPlane(new Cesium.Cartesian3( 1.0, 0.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3(-1.0, 0.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3( 0.0, 1.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3( 0.0, -1.0, 0.0), distance)
],
unionClippingRegions : true,
edgeWidth:3,
edgeColor: Cesium.Color.RED,
enabled : true
});
var rockBox = viewer.entities.add({
name : 'RockBox',
position: Cesium.Cartesian3.fromDegrees(-113.2665534, 36.0939345, 900),
box : {
dimensions : new Cesium.Cartesian3(distance*2, distance*2,800.0),
material : Cesium.Color.GRAY.withAlpha(0.4),
outline : true,
outlineColor : Cesium.Color.GRAY
}
});
var waterTable = viewer.entities.add({
name : 'WaterTable',
position: Cesium.Cartesian3.fromDegrees(-113.2665534, 36.0939345, 440),
box : {
dimensions : new Cesium.Cartesian3(distance*2, distance*2, 160.0),
material : Cesium.Color.BLUE.withAlpha(0.9),
outline : true,
outlineColor : Cesium.Color.BLUE
}
});
viewer.zoomTo(viewer.entities);
javascript cesium
asked Nov 13 '18 at 8:47
visiblemanvisibleman
1,315719
add a comment |
2
I am using the Cesium.Globe clipping planes to extract a square geographic section. But one problem is that terrain back-faces are not rendered which makes it look weird when the user selects a shallow viewing angle.
I thought one way to hide this was to render the "soil" as a box or wall under the terrain, but I would need the top of the box or wall to confirm to the terrain geometry (red line).
I figure I can achieve this by using a WallGeometry around the culled terrain instead of a box, and set the height of each section based on the result of a sampleTerrain call.
But I was wondering if Cesium doesn't provide an easier and cleaner way to do this. (Like perhaps some Boolean union function or something)
Cesium Sandcastle link
var viewer = new Cesium.Viewer('cesiumContainer', {
skyAtmosphere: false,
shouldAnimate : true,
terrainProvider: Cesium.createWorldTerrain()
});
var globe = viewer.scene.globe;
var position = Cesium.Cartographic.toCartesian(new Cesium.Cartographic.fromDegrees(-113.2665534, 36.0939345, 100));
var distance = 3000.0;
globe.clippingPlanes = new Cesium.ClippingPlaneCollection({
modelMatrix : Cesium.Transforms.eastNorthUpToFixedFrame(position),
planes : [
new Cesium.ClippingPlane(new Cesium.Cartesian3( 1.0, 0.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3(-1.0, 0.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3( 0.0, 1.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3( 0.0, -1.0, 0.0), distance)
],
unionClippingRegions : true,
edgeWidth:3,
edgeColor: Cesium.Color.RED,
enabled : true
});
var rockBox = viewer.entities.add({
name : 'RockBox',
position: Cesium.Cartesian3.fromDegrees(-113.2665534, 36.0939345, 900),
box : {
dimensions : new Cesium.Cartesian3(distance*2, distance*2,800.0),
material : Cesium.Color.GRAY.withAlpha(0.4),
outline : true,
outlineColor : Cesium.Color.GRAY
}
});
var waterTable = viewer.entities.add({
name : 'WaterTable',
position: Cesium.Cartesian3.fromDegrees(-113.2665534, 36.0939345, 440),
box : {
dimensions : new Cesium.Cartesian3(distance*2, distance*2, 160.0),
material : Cesium.Color.BLUE.withAlpha(0.9),
outline : true,
outlineColor : Cesium.Color.BLUE
}
});
viewer.zoomTo(viewer.entities);
javascript cesium
asked Nov 13 '18 at 8:47
visiblemanvisibleman
1,315719
1
Unfortunately, I don't think there's an easy way to do this with the public API, but this does look like a good use case. This isn't documented but you can set a custom renderstate for most objects. For terrain you'd have to modify this source to set cull to disabled here: github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/… And this is what it looks like: imgur.com/aWIo86B
– Omar Shehata
Nov 14 '18 at 14:01
This might be a good opportunity to open a pull request to maybe just add a boolean property on terrain to set this, since I think that's vastly easier than constructing all this extra geometry just to hide it.
– Omar Shehata
Nov 14 '18 at 14:03
@OmarShehata, thank you that looks really good and for most use cases it would be enough I think. I'm going to have to give this some thought, as I suspect that at a later point I will have to visualize the "soil walls" anyway for soil layer concentrations of various substances. The Ideal solution for me would be if I could use the terrain as a clipping plane against subsurface geometries.
– visibleman
Nov 15 '18 at 0:41
I opened an issue for this, feel free to chime in there with anything I missed github.com/AnalyticalGraphicsInc/cesium/issues/7266 Terrain as clipping plane sounds like an interesting use case. I'm not sure how hard that'd be or if there's a simpler way.
– Omar Shehata
Nov 15 '18 at 14:52
add a comment |
2
2
2
I am using the Cesium.Globe clipping planes to extract a square geographic section. But one problem is that terrain back-faces are not rendered which makes it look weird when the user selects a shallow viewing angle.
I thought one way to hide this was to render the "soil" as a box or wall under the terrain, but I would need the top of the box or wall to confirm to the terrain geometry (red line).
I figure I can achieve this by using a WallGeometry around the culled terrain instead of a box, and set the height of each section based on the result of a sampleTerrain call.
But I was wondering if Cesium doesn't provide an easier and cleaner way to do this. (Like perhaps some Boolean union function or something)
Cesium Sandcastle link
var viewer = new Cesium.Viewer('cesiumContainer', {
skyAtmosphere: false,
shouldAnimate : true,
terrainProvider: Cesium.createWorldTerrain()
});
var globe = viewer.scene.globe;
var position = Cesium.Cartographic.toCartesian(new Cesium.Cartographic.fromDegrees(-113.2665534, 36.0939345, 100));
var distance = 3000.0;
globe.clippingPlanes = new Cesium.ClippingPlaneCollection({
modelMatrix : Cesium.Transforms.eastNorthUpToFixedFrame(position),
planes : [
new Cesium.ClippingPlane(new Cesium.Cartesian3( 1.0, 0.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3(-1.0, 0.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3( 0.0, 1.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3( 0.0, -1.0, 0.0), distance)
],
unionClippingRegions : true,
edgeWidth:3,
edgeColor: Cesium.Color.RED,
enabled : true
});
var rockBox = viewer.entities.add({
name : 'RockBox',
position: Cesium.Cartesian3.fromDegrees(-113.2665534, 36.0939345, 900),
box : {
dimensions : new Cesium.Cartesian3(distance*2, distance*2,800.0),
material : Cesium.Color.GRAY.withAlpha(0.4),
outline : true,
outlineColor : Cesium.Color.GRAY
}
});
var waterTable = viewer.entities.add({
name : 'WaterTable',
position: Cesium.Cartesian3.fromDegrees(-113.2665534, 36.0939345, 440),
box : {
dimensions : new Cesium.Cartesian3(distance*2, distance*2, 160.0),
material : Cesium.Color.BLUE.withAlpha(0.9),
outline : true,
outlineColor : Cesium.Color.BLUE
}
});
viewer.zoomTo(viewer.entities);
javascript cesium
asked Nov 13 '18 at 8:47
visiblemanvisibleman
1,315719
I am using the Cesium.Globe clipping planes to extract a square geographic section. But one problem is that terrain back-faces are not rendered which makes it look weird when the user selects a shallow viewing angle.
I thought one way to hide this was to render the "soil" as a box or wall under the terrain, but I would need the top of the box or wall to confirm to the terrain geometry (red line).
I figure I can achieve this by using a WallGeometry around the culled terrain instead of a box, and set the height of each section based on the result of a sampleTerrain call.
But I was wondering if Cesium doesn't provide an easier and cleaner way to do this. (Like perhaps some Boolean union function or something)
Cesium Sandcastle link
var viewer = new Cesium.Viewer('cesiumContainer', {
skyAtmosphere: false,
shouldAnimate : true,
terrainProvider: Cesium.createWorldTerrain()
});
var globe = viewer.scene.globe;
var position = Cesium.Cartographic.toCartesian(new Cesium.Cartographic.fromDegrees(-113.2665534, 36.0939345, 100));
var distance = 3000.0;
globe.clippingPlanes = new Cesium.ClippingPlaneCollection({
modelMatrix : Cesium.Transforms.eastNorthUpToFixedFrame(position),
planes : [
new Cesium.ClippingPlane(new Cesium.Cartesian3( 1.0, 0.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3(-1.0, 0.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3( 0.0, 1.0, 0.0), distance),
new Cesium.ClippingPlane(new Cesium.Cartesian3( 0.0, -1.0, 0.0), distance)
],
unionClippingRegions : true,
edgeWidth:3,
edgeColor: Cesium.Color.RED,
enabled : true
});
var rockBox = viewer.entities.add({
name : 'RockBox',
position: Cesium.Cartesian3.fromDegrees(-113.2665534, 36.0939345, 900),
box : {
dimensions : new Cesium.Cartesian3(distance*2, distance*2,800.0),
material : Cesium.Color.GRAY.withAlpha(0.4),
outline : true,
outlineColor : Cesium.Color.GRAY
}
});
var waterTable = viewer.entities.add({
name : 'WaterTable',
position: Cesium.Cartesian3.fromDegrees(-113.2665534, 36.0939345, 440),
box : {
dimensions : new Cesium.Cartesian3(distance*2, distance*2, 160.0),
material : Cesium.Color.BLUE.withAlpha(0.9),
outline : true,
outlineColor : Cesium.Color.BLUE
}
});
viewer.zoomTo(viewer.entities);
javascript cesium
javascript cesium
asked Nov 13 '18 at 8:47
visiblemanvisibleman
1,315719
asked Nov 13 '18 at 8:47
visiblemanvisibleman
1,315719
asked Nov 13 '18 at 8:47
visiblemanvisibleman
1,315719
asked Nov 13 '18 at 8:47
visiblemanvisibleman
1,315719
asked Nov 13 '18 at 8:47
visiblemanvisibleman
1,315719
1,315719
1
Unfortunately, I don't think there's an easy way to do this with the public API, but this does look like a good use case. This isn't documented but you can set a custom renderstate for most objects. For terrain you'd have to modify this source to set cull to disabled here: github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/… And this is what it looks like: imgur.com/aWIo86B
– Omar Shehata
Nov 14 '18 at 14:01
This might be a good opportunity to open a pull request to maybe just add a boolean property on terrain to set this, since I think that's vastly easier than constructing all this extra geometry just to hide it.
– Omar Shehata
Nov 14 '18 at 14:03
@OmarShehata, thank you that looks really good and for most use cases it would be enough I think. I'm going to have to give this some thought, as I suspect that at a later point I will have to visualize the "soil walls" anyway for soil layer concentrations of various substances. The Ideal solution for me would be if I could use the terrain as a clipping plane against subsurface geometries.
– visibleman
Nov 15 '18 at 0:41
I opened an issue for this, feel free to chime in there with anything I missed github.com/AnalyticalGraphicsInc/cesium/issues/7266 Terrain as clipping plane sounds like an interesting use case. I'm not sure how hard that'd be or if there's a simpler way.
– Omar Shehata
Nov 15 '18 at 14:52
add a comment |
1
Unfortunately, I don't think there's an easy way to do this with the public API, but this does look like a good use case. This isn't documented but you can set a custom renderstate for most objects. For terrain you'd have to modify this source to set cull to disabled here: github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/… And this is what it looks like: imgur.com/aWIo86B
– Omar Shehata
Nov 14 '18 at 14:01
This might be a good opportunity to open a pull request to maybe just add a boolean property on terrain to set this, since I think that's vastly easier than constructing all this extra geometry just to hide it.
– Omar Shehata
Nov 14 '18 at 14:03
@OmarShehata, thank you that looks really good and for most use cases it would be enough I think. I'm going to have to give this some thought, as I suspect that at a later point I will have to visualize the "soil walls" anyway for soil layer concentrations of various substances. The Ideal solution for me would be if I could use the terrain as a clipping plane against subsurface geometries.
– visibleman
Nov 15 '18 at 0:41
I opened an issue for this, feel free to chime in there with anything I missed github.com/AnalyticalGraphicsInc/cesium/issues/7266 Terrain as clipping plane sounds like an interesting use case. I'm not sure how hard that'd be or if there's a simpler way.
– Omar Shehata
Nov 15 '18 at 14:52
1
1
Unfortunately, I don't think there's an easy way to do this with the public API, but this does look like a good use case. This isn't documented but you can set a custom renderstate for most objects. For terrain you'd have to modify this source to set cull to disabled here: github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/… And this is what it looks like: imgur.com/aWIo86B
– Omar Shehata
Nov 14 '18 at 14:01
Unfortunately, I don't think there's an easy way to do this with the public API, but this does look like a good use case. This isn't documented but you can set a custom renderstate for most objects. For terrain you'd have to modify this source to set cull to disabled here: github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/… And this is what it looks like: imgur.com/aWIo86B
– Omar Shehata
Nov 14 '18 at 14:01
This might be a good opportunity to open a pull request to maybe just add a boolean property on terrain to set this, since I think that's vastly easier than constructing all this extra geometry just to hide it.
– Omar Shehata
Nov 14 '18 at 14:03
This might be a good opportunity to open a pull request to maybe just add a boolean property on terrain to set this, since I think that's vastly easier than constructing all this extra geometry just to hide it.
– Omar Shehata
Nov 14 '18 at 14:03
@OmarShehata, thank you that looks really good and for most use cases it would be enough I think. I'm going to have to give this some thought, as I suspect that at a later point I will have to visualize the "soil walls" anyway for soil layer concentrations of various substances. The Ideal solution for me would be if I could use the terrain as a clipping plane against subsurface geometries.
– visibleman
Nov 15 '18 at 0:41
@OmarShehata, thank you that looks really good and for most use cases it would be enough I think. I'm going to have to give this some thought, as I suspect that at a later point I will have to visualize the "soil walls" anyway for soil layer concentrations of various substances. The Ideal solution for me would be if I could use the terrain as a clipping plane against subsurface geometries.
– visibleman
Nov 15 '18 at 0:41
I opened an issue for this, feel free to chime in there with anything I missed github.com/AnalyticalGraphicsInc/cesium/issues/7266 Terrain as clipping plane sounds like an interesting use case. I'm not sure how hard that'd be or if there's a simpler way.
– Omar Shehata
Nov 15 '18 at 14:52
I opened an issue for this, feel free to chime in there with anything I missed github.com/AnalyticalGraphicsInc/cesium/issues/7266 Terrain as clipping plane sounds like an interesting use case. I'm not sure how hard that'd be or if there's a simpler way.
– Omar Shehata
Nov 15 '18 at 14:52
add a comment |
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1
Unfortunately, I don't think there's an easy way to do this with the public API, but this does look like a good use case. This isn't documented but you can set a custom renderstate for most objects. For terrain you'd have to modify this source to set cull to disabled here: github.com/AnalyticalGraphicsInc/cesium/blob/master/Source/… And this is what it looks like: imgur.com/aWIo86B
– Omar Shehata
Nov 14 '18 at 14:01
This might be a good opportunity to open a pull request to maybe just add a boolean property on terrain to set this, since I think that's vastly easier than constructing all this extra geometry just to hide it.
– Omar Shehata
Nov 14 '18 at 14:03
@OmarShehata, thank you that looks really good and for most use cases it would be enough I think. I'm going to have to give this some thought, as I suspect that at a later point I will have to visualize the "soil walls" anyway for soil layer concentrations of various substances. The Ideal solution for me would be if I could use the terrain as a clipping plane against subsurface geometries.
– visibleman
Nov 15 '18 at 0:41
I opened an issue for this, feel free to chime in there with anything I missed github.com/AnalyticalGraphicsInc/cesium/issues/7266 Terrain as clipping plane sounds like an interesting use case. I'm not sure how hard that'd be or if there's a simpler way.
– Omar Shehata
Nov 15 '18 at 14:52