Adding a bool (unsupported) variable to a Hydra Shader crashes Hydra (usdview)

[sirpalee]

System Information (OS, Hardware, etc.)

Quadro K4200, Driver Version 370.28

Package Versions

USD: Dev, with the isnan fix applied

Steps to Reproduce

1. Bring in any kind of geometry, and assign a hydra shader to it.
2. Add a bool to the shader
3. Try to view the usd file using usdview

Example usd file

#usda 1.0

over "dragon" (
    add references = @./dragon.usda@
)
{
    rel look:binding = </Test>
}

def Look "Test"
{
    rel displayLook:bxdf = </Test/TestShader>

    def Shader "TestShader"
    {
        uniform asset info:filename = @./alSurface.glslfx@
        float3 diffuseColor = (1.0, 1.0, 1.0)
        float diffuseStrength = 1.0
        bool myCrazyBool = 1
    }
}

The following is the output from usdview.

palm@ws-098:~/data/usd$ usdview ./test.usda 
Floating point exception (core dumped)

I didn't do too much testing yet, my guess is, this happens because booleans are not supported for glslfx shaders, and codeGen creates an invalid shader code. For example, the struct accessor function generators don't check if the type is empty or not. So for instance in this case the generated accessor function will look like this (note the extra space before HdGet...)

 HdGet_myCrazyBool()
{
...
}

Also, from what I saw, this creates a float value on the ShaderData struct, probably that's leading to the floating point exception (it's trying to read the boolean value into a float or something?). I assume the same thing happens with any kind of variable, that's not explicitly supported by Hydra.

[jtran56]

Filed as internal issue #139911.

[sunyab]

Reopening for now, as this commit has not been merged into master.

[sunyab]

This change has been merged into release 0.7.3.