78 lines
2.3 KiB
Text
78 lines
2.3 KiB
Text
|
/* Copyright (c) 2025, Sascha Willems
|
||
|
|
*
|
||
|
|
* SPDX-License-Identifier: MIT
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
struct Attributes
|
||
|
|
{
|
||
|
|
float2 bary;
|
||
|
|
};
|
||
|
|
|
||
|
|
struct Payload
|
||
|
|
{
|
||
|
|
[[vk::location(0)]] float3 hitValue;
|
||
|
|
};
|
||
|
|
|
||
|
|
RaytracingAccelerationStructure accelStruct;
|
||
|
|
RWTexture2D<float4> image;
|
||
|
|
struct UBO
|
||
|
|
{
|
||
|
|
float4x4 viewInverse;
|
||
|
|
float4x4 projInverse;
|
||
|
|
float4 lightPos;
|
||
|
|
};
|
||
|
|
ConstantBuffer<UBO> ubo;
|
||
|
|
|
||
|
|
[shader("raygeneration")]
|
||
|
|
void raygenerationMain()
|
||
|
|
{
|
||
|
|
uint3 LaunchID = DispatchRaysIndex();
|
||
|
|
uint3 LaunchSize = DispatchRaysDimensions();
|
||
|
|
|
||
|
|
const float2 pixelCenter = float2(LaunchID.xy) + float2(0.5, 0.5);
|
||
|
|
const float2 inUV = pixelCenter / float2(LaunchSize.xy);
|
||
|
|
float2 d = inUV * 2.0 - 1.0;
|
||
|
|
float4 target = mul(ubo.projInverse, float4(d.x, d.y, 1, 1));
|
||
|
|
|
||
|
|
RayDesc rayDesc;
|
||
|
|
rayDesc.Origin = mul(ubo.viewInverse, float4(0, 0, 0, 1)).xyz;
|
||
|
|
rayDesc.Direction = mul(ubo.viewInverse, float4(normalize(target.xyz), 0)).xyz;
|
||
|
|
rayDesc.TMin = 0.001;
|
||
|
|
rayDesc.TMax = 10000.0;
|
||
|
|
|
||
|
|
Payload payload;
|
||
|
|
TraceRay(accelStruct, RAY_FLAG_FORCE_OPAQUE, 0xff, 0, 0, 0, rayDesc, payload);
|
||
|
|
|
||
|
|
image[int2(LaunchID.xy)] = float4(payload.hitValue, 0.0);
|
||
|
|
}
|
||
|
|
|
||
|
|
[shader("closesthit")]
|
||
|
|
void closesthitMain(inout Payload payload, in Attributes attribs)
|
||
|
|
{
|
||
|
|
// We need the barycentric coordinates to calculate data for the current position
|
||
|
|
const float3 barycentricCoords = float3(1.0f - attribs.bary.x - attribs.bary.y, attribs.bary.x, attribs.bary.y);
|
||
|
|
|
||
|
|
// With VK_KHR_ray_tracing_position_fetch we can access the vertices for the hit triangle in the shader
|
||
|
|
|
||
|
|
float3 vertexPos0 = HitTriangleVertexPosition(0);
|
||
|
|
float3 vertexPos1 = HitTriangleVertexPosition(1);
|
||
|
|
float3 vertexPos2 = HitTriangleVertexPosition(2);
|
||
|
|
float3 currentPos = vertexPos0 * barycentricCoords.x + vertexPos1 * barycentricCoords.y + vertexPos2 * barycentricCoords.z;
|
||
|
|
|
||
|
|
// Calcualte the normal from above values
|
||
|
|
float3 normal = normalize(cross(vertexPos1 - vertexPos0, vertexPos2 - vertexPos0));
|
||
|
|
normal = normalize(mul(float4(normal, 1.0), WorldToObject4x3()));
|
||
|
|
|
||
|
|
// Basic lighting
|
||
|
|
float3 lightDir = normalize(ubo.lightPos.xyz - currentPos);
|
||
|
|
float diffuse = max(dot(normal, lightDir), 0.0);
|
||
|
|
|
||
|
|
payload.hitValue.rgb = 0.1 + diffuse;
|
||
|
|
}
|
||
|
|
|
||
|
|
[shader("miss")]
|
||
|
|
void missMain(inout Payload payload)
|
||
|
|
{
|
||
|
|
payload.hitValue = float3(0.0, 0.0, 0.2);
|
||
|
|
}
|