46 lines
1.5 KiB
Text
46 lines
1.5 KiB
Text
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/* Copyright (c) 2024, Sascha Willems
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*
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* SPDX-License-Identifier: MIT
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*
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*/
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#version 460
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#extension GL_EXT_ray_tracing : enable
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#extension GL_EXT_nonuniform_qualifier : enable
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// This extension is required for fetching position data in the closes hit shader
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#extension GL_EXT_ray_tracing_position_fetch : require
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layout(location = 0) rayPayloadInEXT vec3 hitValue;
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hitAttributeEXT vec2 attribs;
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layout(binding = 2, set = 0) uniform UBO
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{
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mat4 viewInverse;
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mat4 projInverse;
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vec4 lightPos;
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} ubo;
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void main()
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{
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// We need the barycentric coordinates to calculate data for the current position
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const vec3 barycentricCoords = vec3(1.0 - attribs.x - attribs.y, attribs.x, attribs.y);
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// With VK_KHR_ray_tracing_position_fetch we can access the vertices for the hit triangle in the shader
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vec3 vertexPos0 = gl_HitTriangleVertexPositionsEXT[0];
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vec3 vertexPos1 = gl_HitTriangleVertexPositionsEXT[1];
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vec3 vertexPos2 = gl_HitTriangleVertexPositionsEXT[2];
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vec3 currentPos = vertexPos0 * barycentricCoords.x + vertexPos1 * barycentricCoords.y + vertexPos2 * barycentricCoords.z;
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// Calcualte the normal from above values
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vec3 normal = normalize(cross(vertexPos1 - vertexPos0, vertexPos2 - vertexPos0));
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normal = normalize(vec3(normal * gl_WorldToObjectEXT));
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// Visualize the normal
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hitValue = normal;
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// Basic lighting
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vec3 lightDir = normalize(ubo.lightPos.xyz - currentPos);
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float diffuse = max(dot(normal, lightDir), 0.0);
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hitValue = vec3(0.1 + diffuse);
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}
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