Babylon Native getting different shadow shader code than appears on the Web

[syntheticmagus]

For questions, please use the forum.

Describe the bug Under certain poorly-understood conditions, Babylon.js seems to be sending different shadow shader code to Native than it does to the browser.

From Spector.js:

From ShaderCompilerD3D.cpp:

To Reproduce Replace the default light creation in experience.js with something like the following:

        scene.activeCamera.radius = 5;
        const light = new BABYLON.SpotLight("*spot00", new BABYLON.Vector3(2, 20, -10), new BABYLON.Vector3(0, -1, 0.3), 1.2, 24, scene);

        const shadowGenerator = new BABYLON.ShadowGenerator(128, light);
        shadowGenerator.getShadowMap().renderList.push(scene.meshes[0]);

        const ground = BABYLON.Mesh.CreateGround("Ground", 50, 50, 1, scene);
        ground.position.y = -0.4;

        ground.receiveShadows = true;

Compare with a similarly established Playground on the Web.

Expected behavior If different shader code is passed to Native versus the Web, I would expect that difference to be required to make the shadows work. As it stands, the shadows don't render, and it's unclear why the shader source is different.

[CedricGuillemet]

output is different: packing to 4 floats VS returning 1 float. This is generally the case when you don't have float texture support and pack a float to RGBA8. Looking at the caps in native engine, I think it's the case here: https://github.com/BabylonJS/Babylon.js/blob/c89dbd5ae3ccb3126aa03c84869fbdfa8b7f3e7b/src/Engines/nativeEngine.ts#L851

[bghgary]

We need to check if this still repros since we added float texture support.

[CedricGuillemet]

Some more flags are needed to get same shaders between web and native on my PC: https://github.com/BabylonJS/Babylon.js/blob/18d6cdcda0438711750b4a411e60af7906a4e050/packages/dev/core/src/Engines/nativeEngine.ts#L246 Once tweaked with same caps between web and native, I can see the same shader. Closing this issue: validation tests are testing shadow and this issue exists for the caps : https://github.com/BabylonJS/BabylonNative/issues/553