public static (Matrix4x4 view, Matrix4x4 projection, bool inverseZ) PSMProjection(int lightIndex,
MyRenderingData renderingData, ShadowSettings settings)
{
var camera = GameObject.Find("Main Camera").GetComponent <Camera>();
var cameraView = camera.worldToCameraMatrix;
var cameraProjection = GL.GetGPUProjectionMatrix(camera.projectionMatrix, false);
var light = renderingData.cullResults.visibleLights[lightIndex].light;
var p = light.transform.forward.ToVector4(1);
var l = light.transform.forward.ToVector4(0);
var pView = cameraView * p;
var lView = cameraView * l;
var lClip = cameraProjection * lView.ToVector3().normalized.ToVector4(0);
var pClip = cameraProjection * lView.ToVector3().normalized.ToVector4(1);
var lightNDC = lClip / pClip.w;
var lightView = Matrix4x4.LookAt(lightNDC.ToVector3(), Vector3.forward * .5f, Vector3.up).inverse;
var ndcBounds = new Bounds(Vector3.forward * 0.5f, new Vector3(2, 2, 1));
var ndcBoundVerts = new Vector3[8];
for (int x = -1, i = 0; x <= 1; x += 2)
{
for (int y = -1; y <= 1; y += 2)
{
for (int z = -1; z <= 1; z += 2)
{
ndcBoundVerts[i++] = ndcBounds.center + Vector3.Scale(ndcBounds.extents, new Vector3(x, y, z));
}
}
}
var frustum = BestfitFrustum(false, lightView, ndcBoundVerts);
var inverseZ = Vector3.Dot(lView, -lightNDC.ToVector3()) < 0;
if (settings.debug)
{
ShadowUtils.DrawFrustum(frustum, false, lightView.inverse);
ShadowUtils.DrawBound(ndcBounds, Color.magenta);
Debug.DrawLine(Vector3.forward * 0.5f, lightNDC.ToVector3());
}
return(lightView, Matrix4x4.Frustum(frustum), inverseZ);
}
public static (Matrix4x4 view, Matrix4x4 projection) GetShadowViewProjection(ShadowSettings settings,
MyRenderingData renderingData, int lightIndex)
{
var camera = renderingData.camera;
if (settings.debug)
{
camera = GameObject.Find("Main Camera").GetComponent <Camera>();
}
var cameraToWorld = camera.transform.localToWorldMatrix;
var p0 = cameraToWorld.MultiplyPoint(new Vector3(0, 0, 0));
var h = Mathf.Tan(camera.fieldOfView * Mathf.Deg2Rad / 2);
var w = h * camera.aspect;
var p1 = cameraToWorld.MultiplyPoint(new Vector3(-w, -h, 1) * settings.maxShadowDistance);
var p2 = cameraToWorld.MultiplyPoint(new Vector3(w, -h, 1) * settings.maxShadowDistance);
var p3 = cameraToWorld.MultiplyPoint(new Vector3(w, h, 1) * settings.maxShadowDistance);
var p4 = cameraToWorld.MultiplyPoint(new Vector3(-w, h, 1) * settings.maxShadowDistance);
//左右手坐标转换
var view = Matrix4x4.Scale(new Vector3(1, 1, -1)) * settings.transform.worldToLocalMatrix;
renderingData.cullResults.GetShadowCasterBounds(lightIndex, out var bounds);
//阴影包围盒
var casterBoundVerts = new Vector3[8];
for (int x = -1, i = 0; x <= 1; x += 2)
{
for (int y = -1; y <= 1; y += 2)
{
for (int z = -1; z <= 1; z += 2)
{
casterBoundVerts[i++] = bounds.center + Vector3.Scale(bounds.extents, new Vector3(x, y, z));
}
}
}
var debug = camera.name == "Main Camera" && settings.debug;
if (settings.light.type == LightType.Point)
{
//朝向 + shadow框
var rotation = Matrix4x4.Rotate(Quaternion.FromToRotation(Vector3.forward,
settings.transform.worldToLocalMatrix.MultiplyPoint(bounds.center).normalized));
var rotatedView = rotation.inverse * settings.light.transform.worldToLocalMatrix;
var frustumCaster = BestfitFrustum(false, rotatedView, casterBoundVerts);
if (debug)
{
ShadowUtils.DrawBound(bounds, Color.cyan);
ShadowUtils.DrawFrustum(frustumCaster, false, rotatedView.inverse);
}
return(Matrix4x4.Scale(new Vector3(1, 1, -1)) * rotatedView, Matrix4x4.Frustum(frustumCaster));
}
else if (settings.light.type == LightType.Spot)
{
Matrix4x4 lightView = settings.light.transform.worldToLocalMatrix;
var frustumCamera = BestfitFrustum(false, lightView, p0, p1, p2, p3, p4);
var frustumCaster = BestfitFrustum(false, lightView, casterBoundVerts);
var near = settings.nearDistance;
var far = Mathf.Min(frustumCaster.zFar, frustumCamera.zFar, settings.light.range);
return(view, Matrix4x4.Perspective(settings.light.spotAngle, 1, near, far));
}
else if (settings.light.type == LightType.Directional)
{
//shadow框和摄像机框 比较 选择最大/小的
var frustumCamera =
BestfitFrustum(true, settings.light.transform.worldToLocalMatrix, p0, p1, p2, p3, p4);
var frustumCaster = BestfitFrustum(true, settings.light.transform.worldToLocalMatrix, casterBoundVerts);
var left = Mathf.Max(frustumCaster.left, frustumCamera.left);
var right = Mathf.Min(frustumCaster.right, frustumCamera.right);
var bottom = Mathf.Max(frustumCaster.bottom, frustumCamera.bottom);
var top = Mathf.Min(frustumCaster.top, frustumCamera.top);
var zNear = frustumCaster.zNear;
var zFar = Mathf.Min(frustumCaster.zFar, frustumCamera.zFar);
if (debug)
{
var bound = new Bounds();
bound.min = new Vector3(left, bottom, zNear);
bound.max = new Vector3(right, top, zFar);
ShadowUtils.DrawFrustum(new FrustumPlanes()
{
left = Mathf.Max(frustumCaster.left, frustumCamera.left),
right = Mathf.Min(frustumCaster.right, frustumCamera.right),
bottom = Mathf.Max(frustumCaster.bottom, frustumCamera.bottom),
top = Mathf.Min(frustumCaster.top, frustumCamera.top),
zNear = frustumCaster.zNear,
zFar = Mathf.Min(frustumCaster.zFar, frustumCamera.zFar),
}, true, settings.transform.localToWorldMatrix);
//DrawBound(bounds, Color.cyan);
Debug.DrawRay(
settings.transform.localToWorldMatrix.MultiplyPoint(new Vector3(bound.center.x, bound.center.y,
zNear)), settings.transform.forward * 5, Color.green);
}
return(view, Matrix4x4.Ortho(left, right, bottom, top, zNear, zFar));
}
return(Matrix4x4.identity, Matrix4x4.identity);
}
