shaderMaterial custom attributes

[Alvaro]

Hi guys,

 

I have read some tutorials about ShaderMaterial, but I don't see in any of then if it is possible to add custom attributes apart from position, uv and normal.

 

What I would like is create a list of floats (one for each position) and keep it in the mesh (so far so good).

When creating the ShaderMaterial, I want to add this list as another attribute so I can take the right value for each position when rendering the material and work with it.

 

Any ideas?

 

Cheers.

 

 

[GameMonetize]

Hello, this is perfectly feasible using ShaderMaterial constructor:)

var myShaderMaterial = new BABYLON.ShaderMaterial("cloud", scene, {            vertexElement: "vertexShaderCode",            fragmentElement: "fragmentShaderCode",        },        {            needAlphaBlending: true,            attributes: ["position", "uv", "listOfStuff"],            uniforms: ["worldViewProjection"],            samplers: ["textureSampler"]        });

You have then to use mesh.setVerticesData("listOfStuff", data) to fill your data

[Alvaro]

Thank you Deltakosh!

[Alvaro]

Hi Deltakosh, I did exactly was you told me, but when I define and try to use the new attribute "listOfStuff" in the vertex and fragment files I am getting this error:

 

[.WebGLRenderingContext]GL ERROR :GL_INVALID_OPERATION : glDrawElements: attempt to access out of range vertices in attribute 3 

 

I have checked the mesh and I can see my new list of floats when doing the getVerticesDataKinds, it is looking good. The way I have defined the attribute in the shader is like this:

 

attribute float listOfStuff;

 

It looks like the new attribute is not properly set at the moment the vertex files is executing. I was expecting the same behavior we have with normal, uv and position. Do I have to manually set the attribute values using the "setFloats"? If that is the case, I have to create a new material for each mesh and I was using the same material for several meshes.

 

ideas?

 

Cheers.

[GameMonetize]

This *should* work Could you reproduce it on the playground? Will be easier to help you then

[Alvaro]

ok, I will try, sometime has to be the first time I use the playground.

[Alvaro]

Sorry Deltakosh, but how can I add shaders to the play ground?

[GameMonetize]

Arf yes this is not convenient. Please send me your project then

[Alvaro]

Not sure if this is the right way of sharing this, so let me know about it.

 

I have the proof of concept ready and failing as expected. I am trying to replicated as much as possible what I am doing, so it should give you an idea.

 

I have created a dummy html file (it should work just clicking, well, fail as expected):

https://dl.dropboxusercontent.com/u/63244599/CustomAttributes/CustomAttributes.html

 

It also include a simple js file and two images.

 

Thank you!

[Dad72]

Maybe putting all your files in a .zip would have been more convenient.

[GameMonetize]

Gotcha!

 

I fixed the issue by adding a new parameter to setVerticesData(kind, data, updatable, stride)

 

In you case stride is 1 (size in float of your data)

[Alvaro]

Yes! it works,

 

So depending of the type of the new attribute I have to use a different stride? what about if I have two custom attributes floats? It is 1 + 1.

 

I don't really understand why is 1 but I will try to dig into the code.

 

cheers!

[GameMonetize]

number of float used

in your case only one float

 

for a vec2: 2 floats and so on

[Alvaro]

understood, thank you Deltakosh!