DepthAnimationMaterial: Problem casting shadows taking alpha into account

[Marten Zander]

Hi @zadvorsky,

I have a little problem using the DepthAnimationMaterial. I have a scene with a bunch of instanced grass tufts using the InstancedPrefabBufferGeometry. I want them tufts to cast shadows taking their map's alpha into account. See the image below for an example based on MeshStandardMaterial and MeshDepthMaterial:

Example

In order to achieve this, I have to pass the following parameters to the MeshDepthMaterial in THREE.JS

{ depthPacking: THREE.RGBADepthPacking, map: MY_TEXTURE, alphaTest: 0.5, }.

adding these properties to my DepthAnimationMaterial has no effect besides that shadows disappear. I have the feeling I am missing something fundamental, so I would be very thankful if you could point me in the right direction :)

Thanks in advance and keep up the work!

[Szenia Zadvornykh]

Hey. I haven't tested BAS with any of those features, so there's a good chance I'd need to add some code to support this. I won't be near a computer until Monday, but I'll take a look then if you're still having trouble.

…

On Sat, Jan 26, 2019, 8:19 PM Marten Zander ***@***.*** wrote: Hi @zadvorsky <https://github.com/zadvorsky>, I have a little problem using the DepthAnimationMaterial. I have a scene with a bunch of instanced grass tufts using the InstancedPrefabBufferGeometry. I want them tufts to cast shadows taking their map's alpha into account. See the image below for an example based on MeshStandardMaterial and MeshDepthMaterial: https://i.imgur.com/RY6YVxW.jpg <http://url> In order to achieve this, I have to pass the following parameters to the MeshDepthMaterial in THREE.JS { depthPacking: THREE.RGBADepthPacking, map: MY_TEXTURE, alphaTest: 0.5, } . adding these properties to my DepthAnimationMaterial has no effect besides that shadows disappear. I have the feeling I am missing something fundamental, so I would be very thankful if you could point me in the right direction :) Thanks in advance and keep up the work! — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#32>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABtMPqQHawfNx17kV0J0j8VpsAei_7V0ks5vHP6JgaJpZM4aUeso> .

[Marten Zander]

thanks, I'd really appreciate it

[Szenia Zadvornykh]

Hello again.

I figured out what's happening, but I'll need more time to implement a proper fix. In the meantime, you'll need to do this:

In your animation material, add a alpha test define, and make sure the depthPacking is under uniformValues.

const material = new StandardAnimationMaterial({
  defines: {
    'ALPHATEST': 0.5
  },
  uniformValues: {
    alphaMap: alphaMapTexture,
    depthPacking: THREE.RGBADepthPacking
  }
})

Then when creating the depth material, set the needsUpdate flag for your alpha map.

mesh.customDepthMaterial = BAS.Utils.createDepthAnimationMaterial(material);
mesh.customDepthMaterial.uniforms.alphaMap.value.needsUpdate = true;

And everything should work, hopefully.

[Marten Zander]

Unfortunately no, still no shadows appearing

[Szenia Zadvornykh]

Here's a reduced test case with a BAS animation material + alpha map + custom depth material. Can you work from there and see what isn't working for you?

[Marten Zander]

thanks for the effort, I will test this as soon as I am back to work.

[Marten Zander]

hmm still not working. Also added side: THREE.DoubleSide now. As soon as I add 'ALPHATEST': 0.5; to my defines, shadows disappear completely.

[Szenia Zadvornykh]

Do you have any code you can share?

[Marten Zander]

Unfortunatley no, it would take some time to isolate the code from the rest of my project. Since your demos are working well, I guess the reason for the issue is stuck somewhere else in my code.

As long as I can't confirm the existence of the issue we can consider this as resolved.