Strange 2D full map lighting

[pjcozzi]

Probably due to the multiple sun and moon light sources.

Sandcastle code:

var viewer = new Cesium.Viewer('cesiumContainer', {
    sceneMode: Cesium.SceneMode.SCENE2D
});
var scene = viewer.scene;

var instances = [];

for (var lon = -175.0; lon < 175.0; lon += 5.0) {
  for (var lat = -85.0; lat < 85.0; lat += 5.0) {
    instances.push(new Cesium.GeometryInstance({
      geometry : new Cesium.RectangleGeometry({
        rectangle : Cesium.Rectangle.fromDegrees(lon, lat, lon + 5.0, lat + 5.0),
        vertexFormat : Cesium.PerInstanceColorAppearance.VERTEX_FORMAT
      }),
      attributes : {
        color : Cesium.ColorGeometryInstanceAttribute.fromColor(Cesium.Color.WHITE)
      }
    }));
  }
}

scene.primitives.add(new Cesium.Primitive({
  geometryInstances : instances,
  appearance : new Cesium.PerInstanceColorAppearance()
}));

[pjcozzi]

@kring any chance you are still game for this for 1.0? Two weeks...

[kring]

Not likely, sorry.

[pjcozzi]

No worries. Pushing.

[mramato]

This problem has gotten worse, and also now happens in all scene modes. It changes depending on if the geometry is closed or not, so @bagnell thinks it may be related to normal flipping. It's not a showstopper because it's bad in 1.3 as well, but we should look at this soon after 1.4 releases.

[mramato]

Another example of lighting issues in #2399

[pjcozzi]

forum post

[emackey]

I think this was auto-closed prematurely. #2515 is listed as only a partial fix.

[pjcozzi]

Another forum post

[mramato]

Just an FYI, something is severely wrong with lighting in master for the sample code in the original post. Hopefully this points to an obvious bug.

3D

2D

I also think this bug is probably intertwined with #1578

[mramato]

It's also been brought up on the forum twice recently: post1 post2

[hpinkos]

Just an FYI, something is severely wrong with lighting in master for the sample code

This is because the sample code doesn't supply the right vertex format to the rectangle vertexFormat : Cesium.PerInstanceColorAppearance.VERTEX_FORMAT

But why the default vertexFormat (position/normal/st instead of just position/normal) makes it that weird is beyond me.

[mramato]

Thanks @hpinkos can you please update the original post with the correct code.

[hpinkos]

Came up again: https://groups.google.com/d/msg/cesium-dev/OzfwqMLOr60/BZUlltAfDgAJ

This lighting problem only happens with Primitive, not GroundPrimitive

[pjcozzi]

Related forum thread from https://github.com/AnalyticalGraphicsInc/cesium/issues/1578#issuecomment-41843903:

https://groups.google.com/forum/#!msg/cesium-dev/SZa3vf3Yk8c/5M_f2-eIW4gJ

[pjcozzi]

CC #4122

[pjcozzi]

CC #4571

[lilleyse]

This may be the same problem in this post: https://groups.google.com/forum/#!topic/cesium-dev/wb_dzC9Tjuw

Works fine if the height is left undefined.

const ellipse = {
      semiMinorAxis : 1000000.0,
      semiMajorAxis : 1000000.0,
      material : Cesium.Color.WHITE,
      shadows: Cesium.ShadowMode.DISABLED,
      numberOfVerticalLines: 3,
      outline: false,
      height: 10,
 };

3D:

2D:

[mramato]

The same post @lilleyse linked to above was updated to mention that his problem went away if he forced contextOptions to include the stencil buffer see: http://cesiumjs.org/Cesium/Apps/Sandcastle/?src=Hello%20World.html&label=Showcases&gist=348403bd766c14f97d05bc59dc60e9cd I think this is just a happy accident, but figured I'd mention it here in case it sets off any light bulbs.

[tomermoshe]

Forcing contextOptions to include the stencil buffer doesn't seem to work if height is defined. Not defining height have a major hit on performance for some reason: http://cesiumjs.org/Cesium/Apps/Sandcastle/?src=Hello%20World.html&label=Showcases&gist=e3ebdee8cf5db3192de145e9b2ad9063

[hpinkos]

Hello @tomermoshe, when using entities, if you define a height it uses a Primitive to draw the geometry. When you do not define a height, it is using a GroundPrimitive, which clamps the geometry to the terrain. GroundPrimitives are a little more complex to render, which is why you see a decrease in performance when you do not define height.

[tomermoshe]

Created a possible fix #5736

[lilleyse]

Also related: https://groups.google.com/forum/#!topic/cesium-dev/HsYgOawTCNI

[ggetz]

Reported on the forum: https://community.cesium.com/t/colors-appearing-different-between-3d-and-2d/21634/2