materials/vMaterials_2/Gems/Diamond.mdl

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 *          Copyright 2024 NVIDIA Corporation. All rights reserved.           *
 ******************************************************************************
 
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*/

mdl 1.6;

import ::anno::*;
import ::df::*;
import ::base::*;
import ::math::*;
import ::nvidia::core_definitions::apply_colorfalloff;
import ::nvidia::core_definitions::thick_glass;
import ::state::normal;

const string COPYRIGHT = 
" Copyright 2024 NVIDIA Corporation. All rights reserved.\n"
" MDL MATERIALS ARE PROVIDED PURSUANT TO AN END USER LICENSE  AGREEMENT,\n"
" WHICH WAS ACCEPTED IN ORDER TO GAIN ACCESS TO THIS FILE.  IN PARTICULAR,\n" 
" THE MDL MATERIALS ARE PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND,\n"
" EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF\n"
" MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF\n" 
" COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL NVIDIA\n"
" CORPORATION BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, INCLUDING ANY\n"
" GENERAL, SPECIAL,  INDIRECT, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WHETHER IN\n"
" AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF THE USE OR\n"
" INABILITY TO USE THE MDL MATERIALS OR FROM OTHER DEALINGS IN THE MDL MATERIALS.\n";

/*
bsdf apply_colorfalloff_v2(
    material base = scratched_metal_v2(metal_color: color(1.)),
    uniform color color_0 = color(1.,0.,0.),
    uniform color color_1 = color(0.,1.,0.),
    uniform color color_2 = color(0.,0.,1.),
    uniform color color_3 = color(1.,0.,0.),
    uniform color color_4 = color(0.,1.,0.)
)
 =  material(
    surface: material_surface(
        scattering: df::measured_curve_factor(
            curve_values: color[](color_0,color_1,color_2,color_3,color_4),
            base: base.surface.scattering
        ),
        emission: base.surface.emission
    ),
    volume: base.volume,
    ior: base.ior,
    thin_walled: base.thin_walled,
    geometry: base.geometry
);


material gem_definition(
	color transmission_color = color(1.0),
    uniform color glass_color = color(.95),
    float roughness = 0.0,
    uniform float volume_ior = 1.4f,
    uniform bool dispersion = true,
    uniform float abbe_number = 1.4f,
    uniform float base_thickness = .1,
    float3 normal = ::state::normal()
)
[[
	::anno::hidden()
]]
 = let{
	 
    bsdf glossy_bsdf = ::df::simple_glossy_bsdf(
        mode: ::df::scatter_reflect,
        tint: color(1.),
        roughness_u: roughness
    );
    bsdf glossy_bsdf_transmission = ::df::simple_glossy_bsdf(
        mode: ::df::scatter_transmit,
        tint: transmission_color,
        roughness_u: roughness
    );
	
	bsdf surface_bsdf = ::df::weighted_layer(
            normal: normal,
            weight: 1.,
            layer: ::df::color_fresnel_layer(
                layer: glossy_bsdf,
                base: glossy_bsdf_transmission,
                ior: dispersion?::base::abbe_number_ior(volume_ior, abbe_number):color(volume_ior)
            )
        );
		
} in material(
    thin_walled: false,
    surface: material_surface(scattering: surface_bsdf ),
    volume: material_volume(
        absorption_coefficient: (base_thickness <= 0)? color(0): ::math::log(glass_color) / -base_thickness
    ),
    ior: dispersion?::base::abbe_number_ior(volume_ior, abbe_number):color(volume_ior)
);
*/

export material Diamond(
    color transmission_color = color ( 1.f , 1.f , 1.f)
    [[
        ::anno::display_name("Transmission Color"),
        ::anno::description("Color effect for transmission independent of thickness of the object."),
        ::anno::in_group("Appearance")
    ]],
    uniform color volume_color = color ( 1.f , 1.f , 1.f)
    [[
        ::anno::display_name("Volume Color"),
        ::anno::description("Color effect for volume of the object reached at transmission distance."),
        ::anno::in_group("Appearance")
    ]],
    uniform float clarity =  1.f
    [[
        ::anno::display_name("Clarity"),
        ::anno::description("Use to adapt to size of gem, smaller numbers darken the gem."),
        ::anno::soft_range(0.1,10.0),
        ::anno::in_group("Appearance")
    ]],
    uniform bool dispersion = true
    [[
        ::anno::display_name("Dispersion"),
        ::anno::description("Enable or disable the dispersion."),
        ::anno::in_group("Advanced")
    ]])
[[
    ::anno::display_name("Diamond"),
    ::anno::description("Diamond gem material (Default values based on 2cm stone size.)"),
    ::anno::author("NVIDIA vMaterials"),
	::anno::contributor("Rüdiger Raab"),
	::anno::contributor("Maik Rohland"),
    ::anno::copyright_notice(COPYRIGHT),
	::anno::thumbnail("./.thumbs/Diamond.Diamond.png"),
	::anno::key_words(string[]("gem", "jewelry", "gemstone", "transmissive", "new", "design", "transparent", "diamond", "purple"))
]] = 
let{
	// Gem definition
	// uniform color glass_color = color(.95),
	float roughness = 0.0;
	float volume_ior = 2.42f;
	float abbe_number = 55.f;
	float base_thickness = clarity * 0.1f;
	// float3 normal = ::state::normal()

	bsdf glossy_bsdf = ::df::simple_glossy_bsdf(
        mode: ::df::scatter_reflect,
        tint: color(1.),
        roughness_u: roughness
    );
    bsdf glossy_bsdf_transmission = ::df::simple_glossy_bsdf(
        mode: ::df::scatter_transmit,
        tint: transmission_color,
        roughness_u: roughness
    );
	
	bsdf surface_bsdf = ::df::weighted_layer(
            //normal: normal, // is state::normal anyways, can be omitted
            weight: 1.,
            layer: ::df::color_fresnel_layer(
                layer: glossy_bsdf,
                base: glossy_bsdf_transmission,
                ior: dispersion?::base::abbe_number_ior(volume_ior, abbe_number):color(volume_ior)
            )
    );
	
	bsdf falloff_bsdf =  df::measured_curve_factor(
            curve_values: color[](color( 0.9529412f , 0.972549f , 1.f),
								color( 1.f , 0.9529412f , 0.9960784f),
								color( 0.9529412f , 0.9764706f , 1.f),
								color( 0.9529412f , 1.f , 0.9960784f),
								color( 1.f , 0.9529412f , 0.9843137f)
								),
            base: surface_bsdf
	);
	

	// the apply color falloff function does nothing but add a color gradient while keeping the material'sample
	// other properties
	
	/*
	::nvidia::core_definitions::apply_colorfalloff(
    base:  gem_definition(
        transmission_color:  transmission_color, 	// CHECK
        glass_color:  volume_color,					// CHECK		was modified in the material+_colume expresion	
        roughness:  0.f,							// CHECK				
        volume_ior:  2.42F, 						// CHECK
        dispersion: dispersion,						// CHECK
        abbe_number: 55.f,							// CHECK
        base_thickness:  clarity * 0.1f,			// CHECK
        normal:  ::state::normal ()),				// CHECK
    color_0:  color( 0.9529412f , 0.972549f , 1.f),	// CHECK
    color_1:  color( 1.f , 0.9529412f , 0.9960784f),// CHECK
    color_2:  color( 0.9529412f , 0.9764706f , 1.f),// CHECK
    color_3:  color( 0.9529412f , 1.f , 0.9960784f),// CHECK
    color_4:  color( 1.f , 0.9529412f , 0.9843137f));// CHECK
	*/
	
} in material(
    thin_walled: false,
    surface: material_surface(scattering: falloff_bsdf ),
    volume: material_volume(
        absorption_coefficient: (base_thickness <= 0)? color(0): ::math::log(volume_color) / -base_thickness
    ),
    ior: dispersion?::base::abbe_number_ior(volume_ior, abbe_number):color(volume_ior)
);