Configure shader maps correctly in own software

[rainergericke]

I want to use the new shadowing functionality in our own software. The standard_pbr.frag has changed to consider shadow maps. I don't understand how the shadow maps have to be configured in the shaderset.
What I tried:

    shaderSet->addDescriptorBinding("opacityMap", "VSG_OPACITY_MAP", MATERIAL_DESCRIPTOR_SET, 7, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1,
                                 VK_SHADER_STAGE_FRAGMENT_BIT,
                                 vsg::vec4Array2D::create(1, 1, vsg::Data::Properties{VK_FORMAT_R32G32B32A32_SFLOAT}));
    shaderSet->addDescriptorBinding("lightData", "", VIEW_DESCRIPTOR_SET, 0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1,
                                 VK_SHADER_STAGE_FRAGMENT_BIT, vsg::vec4Array::create(64));    
    vsg::Data::Properties properties;
          properties.format = VK_FORMAT_D32_SFLOAT;
          properties.imageViewType = VK_IMAGE_VIEW_TYPE_2D_ARRAY;
    shaderSet->addDescriptorBinding("shadowMaps", "", VIEW_DESCRIPTOR_SET, 0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1,
                                 VK_SHADER_STAGE_FRAGMENT_BIT, vsg::floatArray3D::create(1, 1, 1, 0.0f, properties));

When I run the program, I get this message:

program_source:146:274: error: cannot reserve 'sampler' resource location at index 0
fragment main0_out main0(main0_in in [[stage_in]], constant PbrData& pbr [[buffer(0)]], constant LightData& lightData [[buffer(1)]], texture2d<float> diffuseMap [[texture(0)]], depth2d_array<float> shadowMaps [[texture(0)]], sampler diffuseMapSmplr [[sampler(0)]], sampler shadowMapsSmplr [[sampler(0)]], bool gl_FrontFacing [[front_facing]])
                                                                                                                                                                                                                                                                                 ^
.
[mvk-error] VK_ERROR_INVALID_SHADER_NV: Fragment shader function could not be compiled into pipeline. See previous logged error.
libc++abi: terminating due to uncaught exception of type vsg::Exception
Compiler failed to build request

Seems my configuration is incomplete or maybe wrong. What should I do?

[robertosfield]

The pbr and phong ShaderSet's in the vsgshaderset example illustrate how it's done so is good starting place, and follow the form:

shaderSet->addDescriptorBinding("lightData", "", VIEW_DESCRIPTOR_SET, 0, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1, VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, vsg::vec4Array::create(64));
shaderSet->addDescriptorBinding("viewportData", "", VIEW_DESCRIPTOR_SET, 1, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1, VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, vsg::vec4Value::create(0,0, 1280, 1024));
shaderSet->addDescriptorBinding("shadowMaps", "", VIEW_DESCRIPTOR_SET, 2, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1, VK_SHADER_STAGE_FRAGMENT_BIT, vsg::floatArray3D::create(1, 1, 1, vsg::Data::Properties{VK_FORMAT_R32_SFLOAT}));

The new vsgcustomshaderset example and the "so new I only check it in yesterday" vsgtextureprojection also create custom ShaderSet that include sections for the vsg::ViewDependentState.

Technically you should be able to get away without defining the DescriptorBinding for the state associated with the ViewDependentState as the above ShaderSet setup include:

 shaderSet->customDescriptorSetBindings.push_back(vsg::ViewDependentStateBinding::create(VIEW_DESCRIPTOR_SET));

The vsg::ViewDependentStateBinding provides the binding information that is required. The ShaderSet::addDescriptorBinding(..) entries are more for signally the functionality to users. Though... I haven't tried o putting the ShaderSet::addDescirptorBinding(..) calls in :-)

One error I spotted in your code was that your code uses 0 for the binding location for both the lightData and the shadowMap, in the above code snippet you'll see 0 and 1 used respectively.

[rainergericke]

Thanks, that was helpful!

[robertosfield]

Great to hear it's working. Shadows add so much to these scenes, must look great with the vehicle animating :-)