EDL doesn't work with translucent styles

[hpinkos]

EDL looks great when all alpha values are 1.0:

But it doesn't work at all if any of the points have a transparency:

var viewer = new Cesium.Viewer('cesiumContainer', {
    terrainProvider: Cesium.createWorldTerrain()
});

// A ~10 billion point 3D Tileset of the city of Montreal, Canada captured in 2015 with a resolution of 20 cm. Tiled and hosted by Cesium ion.
var tileset = viewer.scene.primitives.add(
    new Cesium.Cesium3DTileset({
        url: Cesium.IonResource.fromAssetId(28945),
        pointCloudShading: {
            attenuation: true,
            maximumAttenuation: 2
        }
    })
);

// Fly to a nice overview of the city.
viewer.camera.flyTo({
    destination : new Cesium.Cartesian3(1223285.2286828577, -4319476.080312792, 4562579.020145769),
    orientation : {
        direction : new Cesium.Cartesian3(0.63053223097472, 0.47519958296727743, -0.6136892226931869),
        up : new Cesium.Cartesian3(0.7699959023135587, -0.4824455703743441, 0.41755548379407276)
    },
    easingFunction: Cesium.EasingFunction.QUADRATIC_IN_OUT
});

Sandcastle.addDefaultToolbarButton('Opaque style', function() {
    var styleObject = {
    color:{
        conditions:[
            ["${Classification} === 1","rgb(47,14,159)"],
            ["true","rgb(200,200,200)"]
        ]}};

    tileset.style = new Cesium.Cesium3DTileStyle(styleObject);
});

Sandcastle.addToolbarButton('Translucent style', function() {
    var styleObject = {
    color:{
        conditions:[
            ["${Classification} === 1","rgba(47,14,159,0.8)"],
            ["true","rgb(200,200,200)"]
        ]}};

    tileset.style = new Cesium.Cesium3DTileStyle(styleObject);
});

[lilleyse]

Some thoughts on fixing this:

• PointCloud needs to recognize when the shader style has mixed opaque/translucent content and issue commands in both the CESIUM_3D_TILE and TRANSLUCENT passes. Similar to what Cesium3DTileBatchTable does for JS styles, but harder because the shader style doesn't know what points have what alphas.
  • Note that classification primitives won't work on translucent commands. @likangning93 has a fix for this on a branch in the analytics SDK.
• PointCloudEyeDomeLighting also needs to submit commands to both CESIUM_3D_TILE and TRANSLUCENT as well I think. The blend shader shouldn't write frag depth in the translucent pass (or maybe the derived command will just ignore it??)

This is much easier to solve if all points are opaque or all points are translucent. Having a mix of the two is the complicated part.

[DanRiess]

Hey guys,

I just wanted to add that EDL also doesn't work when the pointcloud tileset has a custom shader with translucencyMode: CustomShaderTranslucencyMode.TRANSLUCENT applied to it.

Is there by any chance a workaround for that nowadays? Either with styles or custom shaders?