Glossy and Diffuse Shaders (How to?)

[adamwparker]

Does anyone know how I can get a similar Glossy and Diffuse shader similar to Eevee? The reason I want these is for how they react to an HDRI reflection map. I've managed to get the HDRI reflection map into Malt and working as expected, but now I want to create a standard Glossy and Diffuse shader using that HDRI.

Any tips would be greatly appreciated. Thanks!

BTW Malt 1.0 is working great! The design is great and I have not had any technical issues.

[pragma37]

I'd like to provide at least basic PBR support, but I haven't got into it yet.

Here are some quickly put together hdri helper functions. (Just keep in mind this is completely wrong from a phsyical standpoint):

/*  META
    @normal: default=NORMAL;
*/
vec3 random_normal_offset(vec3 normal, float angle, float seed)
{
    vec3 random_vec = random_per_pixel(seed).xyz;
    random_vec.xyz = random_vec.xyz * 2.0 - 1.0;

    vec3 tangent = normalize(random_vec - normal * dot(random_vec, normal));
    vec3 bitangent = cross(normal, tangent);
    mat3 TBN = mat3(tangent, bitangent, normal);

    angle = random_per_pixel(seed).w * angle;
    return TBN * vec3(0, sin(angle), cos(angle));
}

/*  META
    @normal: default=NORMAL;
    @roughness: default=1;
    @samples: default=32;
*/
vec3 hdri_diffuse(sampler2D hdri, vec3 normal, float roughness, int samples)
{
    vec3 result = vec3(0);

    for(int i = 0; i < samples; i++)
    {
        vec2 uv = hdri_uv(random_normal_offset(normal, roughness*PI/2, i));
        result += texture(hdri, uv).rgb / samples;
    }
    return result;
}

/*  META
    @normal: default=NORMAL;
    @samples: default=32;
*/
vec3 hdri_specular(sampler2D hdri, vec3 normal, float roughness, int samples)
{
    normal = reflect(view_direction(), normal);
    return hdri_diffuse(hdri, normal, roughness, samples);
}

BTW Malt 1.0 is working great! The design is great and I have not had any technical issues.

Good to know. Thank you!

[adamwparker]

Thank you for the help! I'm willing to contribute with any others that may also want this feature whenever you get around to it. Thanks!