private void OnPreRender()
{
for (int i = 0; i < CascadeStepNum; ++i)
{
if (m_shadowmaps[i] == null)
{
m_shadowmaps[i] = new RenderTexture(m_sceneCamera.pixelWidth, m_sceneCamera.pixelHeight, 24);
}
m_shadowmapCamera.targetTexture = m_shadowmaps[i];
if (m_worldToShadowmapUVMatrixs[i] == null)
{
m_worldToShadowmapUVMatrixs[i] = new Matrix4x4();
}
CascadedShadowMapCameraParams cascadeInfo = m_shadowMapCameraParams[i];
if (cascadeInfo == null)
{
return;
}
m_shadowmapCameraObject.transform.localPosition = cascadeInfo.cameraPosition;
m_shadowmapCameraObject.transform.localRotation = Quaternion.identity;
m_shadowmapCamera.nearClipPlane = 0.05f;
m_shadowmapCamera.farClipPlane = 0.05f + cascadeInfo.cameraZSize;
m_shadowmapCamera.orthographicSize = cascadeInfo.cameraOrthogonalSize;
m_worldToShadowmapUVMatrixs[i] = ProjectionToUVMatrix * GL.GetGPUProjectionMatrix(m_shadowmapCamera.projectionMatrix, false) * m_shadowmapCamera.worldToCameraMatrix;
m_shadowmapCamera.RenderWithShader(m_shadowmapShader, "");
}
//把所有的shadowmap传给GPU，所以如果Cascaded太多的话，带宽是个问题
if (m_shadowmapArray == null)
{
m_shadowmapArray = TextureUtility.CreateTextureArray(m_shadowmaps.ToList <RenderTexture>(), m_sceneCamera.pixelWidth, m_sceneCamera.pixelHeight);
}
else
{
TextureUtility.UpdateTextureArray(m_shadowmapArray, m_shadowmaps.ToList <RenderTexture>());
}
Shader.SetGlobalTexture("_ShadowMapArray", m_shadowmapArray);
Shader.SetGlobalMatrixArray("_WorldToShadowMapUVMatrix", m_worldToShadowmapUVMatrixs);
Shader.SetGlobalVector("_ShadowMapParams", new Vector4(m_sceneCamera.nearClipPlane, m_sceneCamera.farClipPlane, CascadeStepNum, 0));
}
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);
}
}
}
