Benchmarking Procedure

Each BenchData directory contains a COLLADA .dae file. Each of these was converted to several different glTF formats (below). All files except for stand-alone textures were pre-gzipped, and the resulting files were served using Content-Encoding: gzip.

• glTF, all resources separate
• glTF, textures separate, other resources embedded (as data uri)
• glTF, all resources embedded (as data uri)
• Binary glTF, textures separate, other resources embedded (as binary)
• Binary glTF, all resources embedded (as binary)

Finally, these files were loaded and timed in Cesium 1.11 using the HelloWorld minimal Cesium application, with the code in Listing A1.
All data and applications were served locally. Tests were run in Google Chrome 43.0, using device emulation at 1920x1080 with WiFi network emulation (30 Mbps 2ms RTT). Each test was run 5 times, and the mean of the results for each test is reported.

Detailed results

Model	Model	Format	Load time	Size (gzip*)	# files
Cesium_Air	Cesium Air
		gltf, separate	0.32 s	538 KiB	8
		gltf, tex-separate	0.30 s	559 KiB	3
		gltf, all-embedded	0.41 s	540 KiB	1
		bgltf, tex-separate	0.30 s	538 KiB	3
		bgltf, all-embedded	0.29 s	513 KiB	1
LargeTex	Large Tex
		gltf, separate	3.07 s	8.48 MiB	5
		gltf, tex-separate	3.08 s	8.48 MiB	2
		gltf, all-embedded	4.62 s	8.41 MiB	1
		bgltf, tex-separate	3.04 s	8.48 MiB	2
		bgltf, all-embedded	3.05 s	8.31 MiB	1
TenTex	Ten Tex
		gltf, separate	1.58 s	4.91 MiB	16
		gltf, tex-separate	1.48 s	4.91 MiB	11
		gltf, all-embedded	2.48 s	4.95 MiB	1
		bgltf, tex-separate	1.51 s	4.91 MiB	11
		bgltf, all-embedded	1.63 s	4.90 MiB	1
100kTris	100k Tris
		gltf, separate	0.97 s	2.98 MiB	4
		gltf, tex-separate	1.39 s	3.25 MiB	1
		gltf, all-embedded	^	^	^
		bgltf, tex-separate	0.91 s	2.98 MiB	1
		bgltf, all-embedded	^	^	^
BinaryTree	Binary Tree
		gltf, separate	0.70 s	184 KiB	4
		gltf, tex-separate	0.87 s	184 KiB	1
		gltf, all-embedded	^	^	^
		bgltf, tex-separate	0.69 s	184 KiB	1
		bgltf, all-embedded	^	^	^
SpinningTree	Spinning Tree
		gltf, separate	0.64 s	1.24 MiB	4
		gltf, tex-separate	0.73 s	1.34 MiB	1
		gltf, all-embedded	^	^	^
		bgltf, tex-separate	0.59 s	1.24 MiB	1
		bgltf, all-embedded	^	^	^
1200_12th	1200 12th Ave
		gltf, separate	0.85 s	1.25 MiB	31
		gltf, tex-separate	0.87 s	1.31 MiB	22
		gltf, all-embedded	1.25 s	1.30 MiB	1
		bgltf, tex-separate	0.84 s	1.25 MiB	22
		bgltf, all-embedded	1.02 s	1.23 MiB	1
EauClaire	Eau Claire Tower
		gltf, separate	0.55 s	609 KiB	23
		gltf, tex-separate	0.52 s	610 KiB	16
		gltf, all-embedded	0.66 s	539 KiB	1
		bgltf, tex-separate	0.53 s	608 KiB	16
		bgltf, all-embedded	0.56 s	538 KiB	1

^ Results are excluded for “embedded” for files with no textures, as this is exactly the same as “tex-separate”.

* All files compressed except for stand-alone texture files.

Benchmarked formats

All files except for stand-alone textures are always pre-gzipped.

Format	Description
gltf	Standard glTF
bgltf	Binary glTF
separate	all resources as separate files
tex-separate	only textures as separate files, others embedded
all-embedded	all resources embedded

For standard glTF, files are embedded as base64-encoded data uris. For binary glTF, files are embedded as binary.

Model statistics

These statistics are for the optimized models which are then converted to the various glTF formats.

Model	Type	Images	Draw calls	Tris, rendered	Tris, stored	Nodes	Meshes	Materials	Animations
Cesium Air	Typical model	2	5	5,984	~5,984	7	2	2	2
LargeTex	Large texture	1	1	12	12	2	1	1	0
TenTex	Multiple textures	10	10	20	20	11	10	10	0
100kTris	Many triangles	0	5	99,372	99,372	2	5	1	0
BinaryTree	Many objects	0	8191	98,292	12	8,192	1	1	0
SpinningTree	Many animations & keyframes	0	31	372	12	32	1	1	93
1200 12th Ave	Building data, complex	21	3827	30,235		17	1,197	26	0
Eau Claire Tower	Building data, simpler	15	61	387		45	47	17	0

Appendix

Listing A1: Code used for benchmarking.

// Add to HelloWorld.html.
var viewer = new Cesium.Viewer('cesiumContainer', {globe: false, skyBox: false, skyAtmosphere: false});
var scene = viewer.scene;

var timeModelLoad = function(url) {
    var origin = Cesium.Cartesian3.fromDegrees(0.0, 0.0, 0.0);
    var modelMatrix = Cesium.Transforms.headingPitchRollToFixedFrame(origin, 0.0, 0.0, 0.0);

    var timings = [];

    var f = function() {
        var t0 = performance.now();
        var model = scene.primitives.add(Cesium.Model.fromGltf({
            url : url,
            modelMatrix : modelMatrix,
            asynchronous : true,
            minimumPixelSize : 128
        }));

        model.readyPromise.then(function(model) {
            var t1 = performance.now();
            console.log(t1 - t0);
            model.activeAnimations.addAll({
                loop : Cesium.ModelAnimationLoop.REPEAT
            });
        });
    };

    f();
};

timeModelLoad('/BenchData/Cesium_Air/fmt/CesiumAir.gltf');

// Add to server.js when using Node.js.
    app.get('*.bin'  , function(req, res, next) { res.header('Content-Encoding', 'gzip'); next(); });
    app.get('*.glsl' , function(req, res, next) { res.header('Content-Encoding', 'gzip'); next(); });
    app.get('*.gltf' , function(req, res, next) { res.header('Content-Encoding', 'gzip'); next(); });
    app.get('*.bin'  , function(req, res, next) { res.header('Content-Encoding', 'gzip'); next(); });
    app.get('*.bgltf', function(req, res, next) { res.header('Content-Encoding', 'gzip'); next(); });

References

[1] Models provided by Cube Cities.