/// <summary>
/// Determines the size of the frustum needed to cover the viewable area,
/// then creates an appropriate orthographic projection.
/// </summary>
/// <param name="light">The directional light to use</param>
/// <param name="mainCamera">The camera viewing the scene</param>
protected MyOrthographicCamera CalculateFrustum(MyOrthographicCamera lightCamera, MyPerspectiveCamera mainCamera, float minZ, float maxZ)
{
// Shorten the view frustum according to the shadow view distance
Matrix cameraMatrix;
mainCamera.GetWorldMatrix(out cameraMatrix);
Matrix.CreatePerspectiveFieldOfView(mainCamera.FieldOfView, mainCamera.AspectRatio, minZ, maxZ, out lightCamera.CameraSubfrustum);
Matrix wma;
mainCamera.GetViewMatrix(out wma);
lightCamera.CameraSubfrustum = MyCamera.ViewMatrix * lightCamera.CameraSubfrustum;
for (int i = 0; i < 4; i++)
m_splitFrustumCornersVS[i] = m_frustumCornersVS[i + 4] * (minZ / mainCamera.FarClip);
for (int i = 4; i < 8; i++)
m_splitFrustumCornersVS[i] = m_frustumCornersVS[i] * (maxZ / mainCamera.FarClip);
Vector3.Transform(m_splitFrustumCornersVS, ref cameraMatrix, m_frustumCornersWS);
// Position the shadow-caster camera so that it's looking at the centroid,
// and backed up in the direction of the sunlight
//Toto se nemeni per frame!
Matrix viewMatrix = Matrix.CreateLookAt(Vector3.Zero - (m_sunLightDirection * mainCamera.FarClip), Vector3.Zero, new Vector3(0, 1, 0));
// Determine the position of the frustum corners in light space
Vector3.Transform(m_frustumCornersWS, ref viewMatrix, m_frustumCornersLS);
// Calculate an orthographic projection by sizing a bounding box
// to the frustum coordinates in light space
Vector3 mins = m_frustumCornersLS[0];
Vector3 maxes = m_frustumCornersLS[0];
for (int i = 0; i < 8; i++)
{
if (m_frustumCornersLS[i].X > maxes.X)
maxes.X = m_frustumCornersLS[i].X;
else if (m_frustumCornersLS[i].X < mins.X)
mins.X = m_frustumCornersLS[i].X;
if (m_frustumCornersLS[i].Y > maxes.Y)
maxes.Y = m_frustumCornersLS[i].Y;
else if (m_frustumCornersLS[i].Y < mins.Y)
mins.Y = m_frustumCornersLS[i].Y;
if (m_frustumCornersLS[i].Z > maxes.Z)
maxes.Z = m_frustumCornersLS[i].Z;
else if (m_frustumCornersLS[i].Z < mins.Z)
mins.Z = m_frustumCornersLS[i].Z;
}
// Update an orthographic camera for collision detection
lightCamera.UpdateUnscaled(mins.X, maxes.X, mins.Y, maxes.Y, -maxes.Z - SHADOW_MAX_OFFSET, -mins.Z);
lightCamera.SetViewMatrixUnscaled(ref viewMatrix);
// We snap the camera to 1 pixel increments so that moving the camera does not cause the shadows to jitter.
// This is a matter of integer dividing by the world space size of a texel
float diagonalLength = (m_frustumCornersWS[0] - m_frustumCornersWS[6]).Length();
//Make bigger box - ensure rotation and movement stabilization
diagonalLength = MyMath.GetNearestBiggerPowerOfTwo(diagonalLength);
float worldsUnitsPerTexel = diagonalLength / (float)ShadowMapCascadeSize;
Vector3 vBorderOffset = (new Vector3(diagonalLength, diagonalLength, diagonalLength) - (maxes - mins)) * 0.5f;
maxes += vBorderOffset;
mins -= vBorderOffset;
mins /= worldsUnitsPerTexel;
mins.X = (float)Math.Floor(mins.X);
mins.Y = (float)Math.Floor(mins.Y);
mins.Z = (float)Math.Floor(mins.Z);
mins *= worldsUnitsPerTexel;
maxes /= worldsUnitsPerTexel;
maxes.X = (float)Math.Floor(maxes.X);
maxes.Y = (float)Math.Floor(maxes.Y);
maxes.Z = (float)Math.Floor(maxes.Z);
maxes *= worldsUnitsPerTexel;
/*
Matrix proj;
Matrix.CreateOrthographicOffCenter(mins.X, maxes.X, mins.Y, maxes.Y, -maxes.Z - SHADOW_MAX_OFFSET, -mins.Z, out proj);
if (MyUtils.IsEqual(lightCamera.ProjectionMatrix, proj))
{ //cache
return null;
} */
// Update an orthographic camera for use as a shadow caster
lightCamera.Update(mins.X, maxes.X, mins.Y, maxes.Y, -maxes.Z - SHADOW_MAX_OFFSET, -mins.Z);
lightCamera.SetViewMatrix(ref viewMatrix);
return lightCamera;
}
/// <summary>
/// Creates the renderer
/// </summary>
/// <param name="graphicsDevice">The GraphicsDevice to use for rendering</param>
/// <param name="contentManager">The MyCustomContentManager to use for loading content</param>
public MyShadowRenderer(int shadowMapSize, MyRenderTargets renderTarget, MyRenderTargets depthTarget, bool multiThreaded)
{
ShadowMapCascadeSize = shadowMapSize;
m_shadowRenderTarget = renderTarget;
m_shadowDepthTarget = depthTarget;
for (int i = 0; i < NumSplits; i++)
{
m_lightCameras[i] = new MyOrthographicCamera(1, 1, 1, 10);
// Occ queries for shadows are disabled, so save memory by commenting this
//m_occlusionQueriesLists[i] = new List<MyOcclusionQueryIssue>(1024);
m_cascadeQueries[i] = new MyOcclusionQueryIssue(null);
m_visibility[i] = true;
}
MultiThreaded = multiThreaded;
if (MyRenderConstants.RenderQualityProfile.ForwardRender)
MultiThreaded = false;
}
