public void SimpleQuad_ShouldBeIntersected()
{
var vertices = new Vector3[] {
new Vector3(-1, 0, -1),
new Vector3(1, 0, -1),
new Vector3(1, 0, 1),
new Vector3(-1, 0, 1)
};
var indices = new int[] {
0, 1, 2,
0, 2, 3
};
TriangleMesh mesh = new(vertices, indices);
using var rt = new Raytracer();
rt.AddMesh(mesh);
rt.CommitScene();
Hit hit = rt.Trace(new Ray {
Origin = new Vector3(-0.5f, -10, 0),
Direction = new Vector3(0, 1, 0),
MinDistance = 1.0f
});
Assert.Equal(10.0f, hit.Distance, 0);
Assert.Equal(1u, hit.PrimId);
Assert.Equal(mesh, hit.Mesh);
}
public void SimpleQuad_ShouldBeMissed()
{
var vertices = new Vector3[] {
new Vector3(-1, 0, -1),
new Vector3(1, 0, -1),
new Vector3(1, 0, 1),
new Vector3(-1, 0, 1)
};
var indices = new int[] {
0, 1, 2,
0, 2, 3
};
TriangleMesh mesh = new TriangleMesh(vertices, indices);
var rt = new Raytracer();
rt.AddMesh(mesh);
rt.CommitScene();
Hit hit = rt.Trace(new Ray {
Origin = new Vector3(-0.5f, -10, 0),
Direction = new Vector3(0, -1, 0),
MinDistance = 1.0f
});
Assert.False(hit);
}
static void MeasurePinvokeOverhead(int numTrials)
{
var vertices = new Vector3[] {
new Vector3(-1, 0, -1),
new Vector3(1, 0, -1),
new Vector3(1, 0, 1),
new Vector3(-1, 0, 1)
};
var indices = new int[] {
0, 1, 2,
0, 2, 3
};
TriangleMesh mesh = new TriangleMesh(vertices, indices);
var rt = new Raytracer();
rt.AddMesh(mesh);
rt.CommitScene();
Stopwatch stop = Stopwatch.StartNew();
for (int k = 0; k < numTrials; ++k)
{
for (int i = 0; i < 1000000; ++i)
{
rt.Trace(new Ray {
Origin = new Vector3(-0.5f, -10, 0),
Direction = new Vector3(0, 1, 0),
MinDistance = 1.0f
});
}
}
stop.Stop();
Console.WriteLine($"One million rays intersected in {stop.ElapsedMilliseconds / numTrials}ms");
}
public override Color GetColor(Raytracer raytracer, Ray ray, RaycastHit hit, TraceData traceData)
{
Vector2 texCoord;
Vector3 surfaceNormal;
Vector3 tangent, binormal;
bool texCoordAndTangentRequired = NormalMap != null || DiffuseTexture != null || SpecularMap != null || ReflectionMap != null;
texCoordAndTangentRequired = true; // DEBUG
if (texCoordAndTangentRequired)
{
Vector3 localNormal;
Vector3 localTangent;
ColliderUtils.GetTexCoordAndTangent(
hit,
out texCoord, out localNormal, out localTangent
);
tangent = hit.collider.transform.TransformDirection(localTangent);
surfaceNormal = hit.collider.transform.TransformDirection(localNormal);
binormal = Vector3.Cross(tangent, surfaceNormal);
#region Debug Visualisation
#if DEBUG_SHOW_TEX_COORDS
return(new Color(texCoord.x, texCoord.y, 0, 1));
#endif
#if DEBUG_SHOW_BARYCENTRIC_COORDS
Vector3 dbgBc = hit.barycentricCoordinate;
return(new Color(dbgBc.x, dbgBc.y, dbgBc.z, 1));
#endif
#if DEBUG_SHOW_NORMALS
Vector3 dbgLocalNormal = localNormal;
//dbgLocalNormal = new Vector3 (
// Mathf.Abs ( dbgLocalNormal.x ),
// Mathf.Abs ( dbgLocalNormal.y ),
// Mathf.Abs ( dbgLocalNormal.z )
//);
dbgLocalNormal = (dbgLocalNormal + Vector3.one) * 0.5f;
return(new Color(dbgLocalNormal.x, dbgLocalNormal.y, dbgLocalNormal.z, 1));
#endif
#if DEBUG_SHOW_TANGENTS
Vector3 dbgLocalTangent = localTangent;
if (false)
{
dbgLocalTangent = new Vector3(
Mathf.Abs(dbgLocalTangent.x),
Mathf.Abs(dbgLocalTangent.y),
Mathf.Abs(dbgLocalTangent.z)
);
}
else if (false)
{
dbgLocalTangent = new Vector3(
Mathf.Abs(dbgLocalTangent.x > 0 ? dbgLocalTangent.x : 0),
Mathf.Abs(dbgLocalTangent.y > 0 ? dbgLocalTangent.y : 0),
Mathf.Abs(dbgLocalTangent.z > 0 ? dbgLocalTangent.z : 0)
);
}
else
{
dbgLocalTangent = (dbgLocalTangent + Vector3.one) * 0.5f;
}
return(new Color(dbgLocalTangent.x, dbgLocalTangent.y, dbgLocalTangent.z, 1));
#endif
#if DEBUG_SHOW_BINORMALS
Vector3 localBinormal = Vector3.Cross(localTangent, localNormal);
Vector3 dbgBinormal = localBinormal;
dbgBinormal = new Vector3(
Mathf.Abs(dbgBinormal.x),
Mathf.Abs(dbgBinormal.y),
Mathf.Abs(dbgBinormal.z)
);
return(new Color(dbgBinormal.x, dbgBinormal.y, dbgBinormal.z, 1));
#endif
#endregion Debug Visualisation
}
else
{
texCoord = Vector2.zero;
surfaceNormal = hit.normal;
tangent = Vector3.zero;
binormal = Vector3.zero;
}
bool entering = Vector3.Dot(hit.normal, ray.direction) <= 0;
surfaceNormal = entering ? surfaceNormal : -surfaceNormal;
/* TODO: revise where "entering" calculated upon hit.normal should be replaced
* with "entering" calculated upon surfaceNormal transformed with TBN. */
if (NormalMap != null && NormalMapInfluence > 0)
{
var normalMapRt = TextureCache.FromUnityTexture(NormalMap);
Color normalMapColor = normalMapRt.GetFilteredPixel(texCoord.x, texCoord.y);
Vector3 texNormal = new Vector3(normalMapColor.r, normalMapColor.g, normalMapColor.b);
texNormal = 2 * texNormal - Vector3.one;
texNormal.Normalize();
Vector3 texNormalWorld = Raytracer.TransformTbn(texNormal, tangent, binormal, surfaceNormal);
float normalMapInfluence = Mathf.Clamp01(NormalMapInfluence);
surfaceNormal = Vector3.Lerp(surfaceNormal, texNormalWorld, normalMapInfluence).normalized;
#if DEBUG_SHOW_SURFACE_NORMALS
Vector3 dbgSurfaceNormal = surfaceNormal;
//dbgSurfaceNormal = new Vector3 (
// Mathf.Abs ( dbgSurfaceNormal.x ),
// Mathf.Abs ( dbgSurfaceNormal.y ),
// Mathf.Abs ( dbgSurfaceNormal.z )
//);
dbgSurfaceNormal = (dbgSurfaceNormal + Vector3.one) * 0.5f;
return(new Color(dbgSurfaceNormal.x, dbgSurfaceNormal.y, dbgSurfaceNormal.z, 1));
#endif
}
float specularIntensity = SpecularComponent;
if (SpecularMap != null && SpecularMapInfluence > 0 && specularIntensity > 0)
{
var specularMapRt = TextureCache.FromUnityTexture(SpecularMap);
Color specularMapColor = specularMapRt.GetFilteredPixel(texCoord.x, texCoord.y);
specularIntensity *= specularMapColor.grayscale * specularMapColor.a;
float specularMapInfluence = Mathf.Clamp01(SpecularMapInfluence);
specularIntensity = Mathf.Lerp(SpecularComponent, specularIntensity, specularMapInfluence);
}
Color totalColor = Color.black;
Color diffuseLightSumColor = raytracer.OverrideAmbientLight ? raytracer.AmbientLight : RenderSettings.ambientLight;
diffuseLightSumColor *= DiffuseComponent;
Color specularLightSumColor = Color.black;
var lights = Light.GetLights(LightType.Point, 0);
foreach (var light in lights)
{
Vector3 vToLight = light.transform.position - hit.point;
float lightVolumeRadius = light.range * 0.00625f; // Empirical coefficient.
float distance = vToLight.magnitude - lightVolumeRadius;
if (distance < 0)
{
distance = 0;
}
else if (distance >= light.range)
{
continue;
}
Vector3 dirToLight = vToLight.normalized;
float attenuation;
attenuation = 1 - distance / light.range;
attenuation = attenuation * attenuation;
float lightIntensity = light.intensity * LightIntensityFactor;
if (DiffuseComponent > 0)
{
float diffuseIntensity = Vector3.Dot(dirToLight, surfaceNormal);
if (diffuseIntensity > 0)
{
diffuseIntensity = Mathf.Pow(diffuseIntensity, DiffuseExponent);
Color diffuseLightColor = light.color * attenuation * diffuseIntensity * lightIntensity;
diffuseLightSumColor += diffuseLightColor;
}
}
if (specularIntensity > 0)
{
Vector3 reflectionDir = Vector3.Reflect(-dirToLight, surfaceNormal);
Vector3 vToView = raytracer.Camera.transform.position - hit.point;
Vector3 dirToView = vToView.normalized;
float specularity = Vector3.Dot(reflectionDir, dirToView);
if (specularity > 0)
{
specularity = Mathf.Pow(specularity, SpecularPower);
Color specularLightColor = light.color * attenuation * specularity * lightIntensity;
specularLightSumColor += specularLightColor;
}
}
}
Color diffuseColor;
if (DiffuseTexture != null)
{
var diffuseTextureRt = TextureCache.FromUnityTexture(DiffuseTexture);
// TODO: calculate miplevel, get the color according to its value.
Color texColor = diffuseTextureRt.GetFilteredPixel(texCoord.x, texCoord.y);
if (texColor.a < 1 && DiffuseColorIsBackground)
{
diffuseColor = Color.Lerp(this.DiffuseColor, texColor, texColor.a);
}
else
{
diffuseColor = Color.Lerp(Color.black, texColor, texColor.a);
}
diffuseColor.a = texColor.a;
}
else
{
diffuseColor = this.DiffuseColor;
}
totalColor = diffuseLightSumColor * diffuseColor * DiffuseComponent + specularLightSumColor * specularIntensity;
if (raytracer.MustInterrupt(totalColor, traceData))
{
return(totalColor);
}
bool willReflect;
float reflectionIntensity;
if (entering)
{
willReflect = ReflectionComponent > 0 && traceData.NumReflections < raytracer.MaxReflections;
reflectionIntensity = ReflectionComponent;
}
else
{
willReflect = InnerReflectionComponent > 0 && traceData.NumInnerReflections < raytracer.MaxInnerReflections;
reflectionIntensity = InnerReflectionComponent;
}
if (willReflect && ReflectionMap != null && ReflectionMapInfluence > 0)
{
var reflectionMapRt = TextureCache.FromUnityTexture(ReflectionMap);
Color reflectionMapColor = reflectionMapRt.GetFilteredPixel(texCoord.x, texCoord.y);
float reflectionMapIntensity = reflectionMapColor.grayscale * reflectionMapColor.a;
float reflectionMapInfluence = Mathf.Clamp01(ReflectionMapInfluence);
reflectionIntensity = Mathf.Lerp(reflectionIntensity, reflectionMapIntensity * reflectionIntensity, reflectionMapInfluence);
willReflect = reflectionIntensity > 0;
}
float refractionIntensity = RefractionComponent;
if (RefractWhereTranslucent)
{
refractionIntensity *= 1 - diffuseColor.a * DiffuseComponent;
}
bool willRefract = refractionIntensity > 0 && traceData.NumRefractions < raytracer.MaxRefractions;
bool forkingRequired = willReflect && willRefract;
TraceData tdForRefraction;
if (forkingRequired)
{
tdForRefraction = traceData.Fork();
}
else
{
tdForRefraction = traceData;
}
if (willReflect)
{
if (entering)
{
traceData.NumReflections++;
traceData.Counters.Reflections++;
}
else
{
traceData.NumInnerReflections++;
traceData.Counters.InnerReflections++;
}
Vector3 reflectionDir = Vector3.Reflect(ray.direction, surfaceNormal);
Vector3 pushedOutPoint = hit.point + reflectionDir * Raytracer.PushOutMagnitude;
Color reflectionColor = raytracer.Trace(new Ray(pushedOutPoint, reflectionDir), traceData);
totalColor += reflectionColor * reflectionIntensity;
if (raytracer.MustInterrupt(totalColor, traceData))
{
return(totalColor);
}
}
if (willRefract)
{
tdForRefraction.NumRefractions++;
tdForRefraction.Counters.Refractions++;
CoefficientOut = RefractionIndex;
CoefficientIn = 1 / RefractionIndex;
if (CoefficientOut > 1)
{
CriticalOutAngleCos = Mathf.Sqrt(1 - CoefficientIn * CoefficientIn);
CriticalInAngleCos = 0;
}
else
{
CriticalOutAngleCos = 0;
CriticalInAngleCos = Mathf.Sqrt(1 - CoefficientOut * CoefficientOut);
}
float criticalAngleCos = entering ? CriticalInAngleCos : CriticalOutAngleCos;
Vector3 refractionDir;
float nDotRay = Vector3.Dot(surfaceNormal, ray.direction);
if (Mathf.Abs(nDotRay) >= criticalAngleCos)
{
if (entering)
{
tdForRefraction.PenetrationStack.Push(hit);
}
else
{
tdForRefraction.PenetrationStack.Pop();
}
float k = entering ? CoefficientIn : CoefficientOut;
refractionDir = Raytracer.Refract(ray.direction, surfaceNormal, nDotRay, k);
refractionDir.Normalize();
}
else // Total internal reflection.
{
refractionDir = Vector3.Reflect(ray.direction, surfaceNormal);
}
Vector3 pushedOutPoint = hit.point + refractionDir * Raytracer.PushOutMagnitude;
Color refractionColor = raytracer.Trace(new Ray(pushedOutPoint, refractionDir), tdForRefraction);
if (ColorAberration != 0 && entering)
{
//float rDotRay = Vector3.Dot ( refractionDir, ray.direction );
refractionColor = HsvColor.ChangeHue(refractionColor, (1 + nDotRay) * ColorAberration);
}
totalColor += refractionColor * refractionIntensity;
if (raytracer.MustInterrupt(totalColor, tdForRefraction))
{
return(totalColor);
}
}
return(totalColor);
}
public static void MeasurePinvokeOverhead(int numTrials)
{
var vertices = new Vector3[] {
new Vector3(-1, 0, -1),
new Vector3(1, 0, -1),
new Vector3(1, 0, 1),
new Vector3(-1, 0, 1)
};
var indices = new int[] {
0, 1, 2,
0, 2, 3
};
TriangleMesh mesh = new TriangleMesh(vertices, indices);
var rt = new Raytracer();
rt.AddMesh(mesh);
rt.CommitScene();
Random rng = new(1337);
Stopwatch stop = Stopwatch.StartNew();
for (int k = 0; k < numTrials; ++k)
{
for (int i = 0; i < 1000000; ++i)
{
rt.Trace(new Ray {
Origin = new Vector3(
(float)rng.NextDouble(),
(float)rng.NextDouble(),
(float)rng.NextDouble()),
Direction = new Vector3(
(float)rng.NextDouble(),
(float)rng.NextDouble(),
(float)rng.NextDouble()),
MinDistance = 0.0f
});
}
}
stop.Stop();
Console.WriteLine($"One million rays intersected in {stop.ElapsedMilliseconds / numTrials}ms");
long traceCost = stop.ElapsedMilliseconds / numTrials;
stop = Stopwatch.StartNew();
for (int k = 0; k < numTrials; ++k)
{
for (int i = 0; i < 1000000; ++i)
{
new Vector3(
(float)rng.NextDouble(),
(float)rng.NextDouble(),
(float)rng.NextDouble()
);
new Vector3(
(float)rng.NextDouble(),
(float)rng.NextDouble(),
(float)rng.NextDouble()
);
}
}
stop.Stop();
Console.WriteLine($"RNG overhead: {stop.ElapsedMilliseconds / numTrials}ms");
long rngCost = stop.ElapsedMilliseconds / numTrials;
Console.WriteLine($"Pure cost for tracing + overhead: {traceCost-rngCost}ms");
}
public static void ComplexScene(int numTrials)
{
// the scene is compressed to avoid git issues
if (!File.Exists("../Data/breakfast_room.obj"))
{
ZipFile.ExtractToDirectory("../Data/breakfast_room.zip", "../Data");
}
Stopwatch stop = Stopwatch.StartNew();
List <TriangleMesh> meshes = new();
Vector3 min = Vector3.One * float.MaxValue;
Vector3 max = -Vector3.One * float.MaxValue;
Assimp.AssimpContext context = new();
var scene = context.ImportFile("../Data/breakfast_room.obj",
Assimp.PostProcessSteps.GenerateNormals | Assimp.PostProcessSteps.JoinIdenticalVertices |
Assimp.PostProcessSteps.PreTransformVertices | Assimp.PostProcessSteps.Triangulate);
foreach (var m in scene.Meshes)
{
var material = scene.Materials[m.MaterialIndex];
string materialName = material.Name;
Vector3[] vertices = new Vector3[m.VertexCount];
for (int i = 0; i < m.VertexCount; ++i)
{
vertices[i] = new(m.Vertices[i].X, m.Vertices[i].Y, m.Vertices[i].Z);
}
meshes.Add(new(vertices, m.GetIndices()));
min.X = MathF.Min(min.X, m.BoundingBox.Min.X);
min.Y = MathF.Min(min.X, m.BoundingBox.Min.Y);
min.Z = MathF.Min(min.X, m.BoundingBox.Min.Z);
max.X = MathF.Max(max.X, m.BoundingBox.Max.X);
max.Y = MathF.Max(max.X, m.BoundingBox.Max.Y);
max.Z = MathF.Max(max.X, m.BoundingBox.Max.Z);
}
var diagonal = max - min;
Console.WriteLine($"Scene loaded in {stop.ElapsedMilliseconds}ms");
stop.Restart();
var rt = new Raytracer();
foreach (var m in meshes)
{
rt.AddMesh(m);
}
rt.CommitScene();
Console.WriteLine($"Acceleration structures built in {stop.ElapsedMilliseconds}ms");
Random rng = new(1337);
Vector3 NextVector() => new Vector3(
(float)rng.NextDouble(),
(float)rng.NextDouble(),
(float)rng.NextDouble());
stop.Restart();
float averageDistance = 0;
for (int k = 0; k < numTrials; ++k)
{
for (int i = 0; i < 1000000; ++i)
{
var hit = rt.Trace(new Ray {
Origin = NextVector() * diagonal + min,
Direction = NextVector(),
MinDistance = 0.0f
});
if (hit)
{
averageDistance += hit.Distance / 1000000 / numTrials;
}
}
}
stop.Stop();
Console.WriteLine($"One million closest hits found in {stop.ElapsedMilliseconds / numTrials}ms");
Console.WriteLine($"Average distance: {averageDistance}");
stop.Restart();
float averageVisibility = 0;
for (int k = 0; k < numTrials; ++k)
{
for (int i = 0; i < 1000000; ++i)
{
bool occluded = rt.IsOccluded(new ShadowRay(new Ray {
Origin = NextVector() * diagonal + min,
Direction = NextVector(),
MinDistance = 0.0f
}, maxDistance: (float)rng.NextDouble() * averageDistance * 5));
if (!occluded)
{
averageVisibility += 1.0f / 1000000.0f / numTrials;
}
}
}
stop.Stop();
Console.WriteLine($"One million any hits found in {stop.ElapsedMilliseconds / numTrials}ms");
Console.WriteLine($"Average visibility: {averageVisibility}");
}
private static void RaycastingMesh(Texture2D texture, float3 cameraPosition, float3 lightPosition, float3 target)
{
// View and projection matrices
var viewMatrix = Transforms.LookAtLH(cameraPosition, target, float3.up);
var projectionMatrix =
Transforms.PerspectiveFovLH(pi_over_4, texture.Height / (float)texture.Width, 0.01f, 20);
var scene = new Scene <PositionNormal>();
CreateMeshScene(scene);
// Raycaster to trace rays and check for shadow rays.
var shadower = new Raytracer <ShadowRayPayload, PositionNormal>();
shadower.OnAnyHit += (IRaycastContext context, PositionNormal attribute, ref ShadowRayPayload payload) =>
{
// If any object is found in ray-path to the light, the ray is shadowed.
payload.Shadowed = true;
// No necessary to continue checking other objects
return(HitResult.Stop);
};
// Raycaster to trace rays and lit closest surfaces
var raycaster = new Raytracer <RayPayload, PositionNormal>();
raycaster.OnClosestHit += (IRaycastContext context, PositionNormal attribute, ref RayPayload payload) =>
{
// Move geometry attribute to world space
attribute = attribute.Transform(context.FromGeometryToWorld);
var V = normalize(cameraPosition - attribute.Position);
var L = normalize(lightPosition - attribute.Position);
var lambertFactor = max(0, dot(attribute.Normal, L));
// Check ray to light...
var shadow = new ShadowRayPayload();
shadower.Trace(scene,
RayDescription.FromTo(
attribute.Position +
attribute.Normal * 0.001f, // Move an epsilon away from the surface to avoid self-shadowing
lightPosition), ref shadow);
payload.Color = shadow.Shadowed ? float3(0, 0, 0) : float3(1, 1, 1) * lambertFactor;
};
raycaster.OnMiss += (IRaycastContext context, ref RayPayload payload) =>
{
payload.Color = float3(0, 0, 1); // Blue, as the sky.
};
// Render all points of the screen
for (var px = 0; px < texture.Width; px++)
{
for (var py = 0; py < texture.Height; py++)
{
var progress = px * texture.Height + py;
if (progress % 100 == 0)
{
Console.Write("\r" + progress * 100 / (float)(texture.Width * texture.Height) + "% ");
}
var ray = RayDescription.FromScreen(px + 0.5f, py + 0.5f, texture.Width, texture.Height,
inverse(viewMatrix), inverse(projectionMatrix), 0, 1000);
var coloring = new RayPayload();
raycaster.Trace(scene, ray, ref coloring);
texture.Write(px, py, float4(coloring.Color, 1));
}
}
Console.Write("\r" + 100 + "% ");
}