/// <summary>
/// 通过顶点列表获取AABB包围盒
/// </summary>
/// <param name="vertexList"></param>
/// <returns></returns>
public static AABBBounds GetAABBBoundsByVertexList(List <Vector3> vertexList)
{
AABBBounds aabbBounds = new AABBBounds();
for (int i = 0; i < vertexList.Count; ++i)
{
aabbBounds.UpdatePoint(vertexList[i]);
}
return(aabbBounds);
}
public static AABBBounds GetAABBBoundsOnTargetSpace(Transform targetSpaceTransform, List <Vector3> worldVertexList)
{
AABBBounds aabbBounds = new AABBBounds();
foreach (Vector3 vertex in worldVertexList)
{
Vector3 pointOnTargetSpace = targetSpaceTransform.worldToLocalMatrix.MultiplyPoint(vertex);
aabbBounds.UpdatePoint(pointOnTargetSpace);
}
return(aabbBounds);
}
/// <summary>
/// 设置LightCamera 适应视角
/// </summary>
/// <param name="lightTransform"></param>
/// <param name="lightCamera"></param>
/// <param name="mainCamera"></param>
/// <param name="sceneConnerList"></param>
private void SetLightCameraFitView(Transform lightTransform, Camera lightCamera, Camera mainCamera, List <Vector3> sceneConnerList)
{
List <Vector3> mainCameraFrustumConners = GetCameraPerspectiveFrustumConners(mainCamera);
AABBBounds frustumBoundsInLightSpace = new AABBBounds();
mainCameraFrustumConners.ForEach(connerVertex =>
{
Vector3 worldFrustumConner = mainCamera.transform.localToWorldMatrix.MultiplyPoint(connerVertex);
Vector3 pointInLightSpace = lightTransform.worldToLocalMatrix.MultiplyPoint(worldFrustumConner);
frustumBoundsInLightSpace.UpdatePoint(pointInLightSpace);
});
AABBBounds sceneBounds = GetSceneAABBBoundsInTargetSpace(sceneConnerList, lightTransform);
//计算Frustum 时，需要注意，如果Camera.farpanel 特别大，计算出的AABB太大， 所以可以采取AABBFrustum 跟 SceneAABB 相交作为最终的投影包围体
//或者设置farpanel neaarpanel到合理的大小
//lightCamera.transform.localPosition = new Vector3(frustumBoundsInLightSpace.Center.x, frustumBoundsInLightSpace.Center.y, frustumBoundsInLightSpace.Min.z - 0.05f);
//lightCamera.orthographicSize = Mathf.Max(frustumBoundsInLightSpace.Extends.x, frustumBoundsInLightSpace.Extends.y);
//lightCamera.nearClipPlane = 0.05f;
//lightCamera.farClipPlane = 0.05f + (frustumBoundsInLightSpace.Size.z);
Vector3 shadowCameraMin = new Vector3(
Mathf.Max(sceneBounds.Min.x, frustumBoundsInLightSpace.Min.x),
Mathf.Max(sceneBounds.Min.y, frustumBoundsInLightSpace.Min.y),
Mathf.Max(sceneBounds.Min.z, frustumBoundsInLightSpace.Min.z));
Vector3 shadowCameraMax = new Vector3(
Mathf.Min(sceneBounds.Max.x, frustumBoundsInLightSpace.Max.x),
Mathf.Min(sceneBounds.Max.y, frustumBoundsInLightSpace.Max.y),
Mathf.Min(sceneBounds.Max.z, frustumBoundsInLightSpace.Max.z));
Vector3 center = (shadowCameraMax + shadowCameraMin) / 2;
Vector3 extends = (shadowCameraMax - shadowCameraMin) / 2;
lightCamera.transform.localPosition = new Vector3(center.x, center.y, shadowCameraMin.z - 0.05f);
lightCamera.orthographicSize = Mathf.Max(extends.x, extends.y);
lightCamera.nearClipPlane = 0.05f;
lightCamera.farClipPlane = 0.05f + (extends.z * 2);
Matrix4x4 lightCameraProjectionUVMatrix = new Matrix4x4();
Vector3 transpose = new Vector3(0.5f, 0.5f, 0);
Vector3 scale = new Vector3(0.5f, 0.5f, 1);
lightCameraProjectionUVMatrix.SetTRS(transpose, Quaternion.identity, scale);
lightCameraProjectionUVMatrix = lightCameraProjectionUVMatrix * GL.GetGPUProjectionMatrix(lightCamera.projectionMatrix, false) * lightCamera.worldToCameraMatrix;
Shader.SetGlobalMatrix("_LightSpaceProjectionUVMatrix", lightCameraProjectionUVMatrix);
}
private AABBBounds GetSceneAABBBoundsInTargetSpace(List <Vector3> worldConnerList, Transform targetSpace)
{
AABBBounds boundsInLightSpace = new AABBBounds();
worldConnerList.ForEach(worldConnerVertex =>
{
Vector3 connerPosInLightSpace = targetSpace.worldToLocalMatrix.MultiplyPoint(worldConnerVertex);
boundsInLightSpace.UpdatePoint(connerPosInLightSpace);
});
return(boundsInLightSpace);
}
public static AABBBounds GetAABBBoundsOnWorldSpace(List <Vector3> vertexList, Transform relativeToSpace)
{
AABBBounds aabbBounds = new AABBBounds();
foreach (Vector3 vertex in vertexList)
{
Vector3 worldPos = relativeToSpace.localToWorldMatrix.MultiplyPoint(vertex);
aabbBounds.UpdatePoint(worldPos);
}
return(aabbBounds);
}
private void UpdateShadowmapCameraParams(BoundsType boundsType)
{
if (boundsType == BoundsType.AABB)
{
for (int i = 0; i < CascadeStepNum; ++i)
{
List <Vector3> frustumVertex = m_cameraFrustumList[i];
AABBBounds frustumBoundsOnLightSpace = GeometryUtility.GetAABBBoundsOnTargetSpace(Mainlight.transform, frustumVertex);
CascadedShadowMapCameraParams cameraParams = new CascadedShadowMapCameraParams();
cameraParams.cameraPosition = new Vector3(frustumBoundsOnLightSpace.Center.x, frustumBoundsOnLightSpace.Center.y, frustumBoundsOnLightSpace.Min.z - 0.05f);
cameraParams.cameraOrthogonalSize = Mathf.Max(frustumBoundsOnLightSpace.Extends.x, frustumBoundsOnLightSpace.Extends.y) / 2; //todo:orthogonalSize算法需要以后好好研究一下
cameraParams.cameraZSize = frustumBoundsOnLightSpace.Size.z;
m_shadowMapCameraParams.Add(cameraParams);
}
}
}
/// <summary>
/// 摄像机正适应场景
/// </summary>
/// <param name="lightTransform"></param>
/// <param name="lightCamara"></param>
/// <param name="sceneConnerList"></param>
private void SetLightCameraFitScene(Transform lightTransform, Camera lightCamara, List <Vector3> sceneConnerList)
{
AABBBounds boundsInLightSpace = GetSceneAABBBoundsInTargetSpace(sceneConnerList, lightTransform);
//由于lightcamera,位置由x,y确定，z由 camera.near far确定 脑补一下侧视图 还有俯视图
//x,y的中间就是摄像机位置，z值为near~far 需要保证near~far大于0
lightCamara.transform.localPosition = new Vector3(boundsInLightSpace.Center.x, boundsInLightSpace.Center.y, boundsInLightSpace.Min.z - 0.05f);
lightCamara.orthographicSize = Mathf.Max(boundsInLightSpace.Extends.x, boundsInLightSpace.Extends.y);
lightCamara.nearClipPlane = 0.05f;
lightCamara.farClipPlane = 0.05f + (boundsInLightSpace.Size.z);
Matrix4x4 lightCameraProjectionUVMatrix = new Matrix4x4();
Vector3 transpose = new Vector3(0.5f, 0.5f, 0f);
Vector3 scale = new Vector3(0.5f, 0.5f, 1f);
lightCameraProjectionUVMatrix.SetTRS(transpose, Quaternion.identity, scale);
// (P*V) *0.5 +0.5
lightCameraProjectionUVMatrix = lightCameraProjectionUVMatrix * GL.GetGPUProjectionMatrix(lightCamara.projectionMatrix, false) * lightCamara.worldToCameraMatrix;
Shader.SetGlobalMatrix("_LightSpaceProjectionUVMatrix", lightCameraProjectionUVMatrix);
}
