MJP's CSM. Shadows moving

[mgoss 225]

I'm using MJP's CSM shadow code and I'm having major issues with the shadows moving with the camera. Here a video to demonstrate what's going on. Also, is there a way to fix the dueling frustum issue? It's annoying seeing them pop in and out of corners of the screen.

[media]

[/media]


using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
namespace Craft
{
public class CascadedShadowMap
{
static SpriteBatch spriteBatch = Engine.SpriteBatch;
static int width = Engine.BackBufferWidth;
static int height = Engine.BackBufferHeight;
const int SHADOW_RESOLUTION = 1024;
const int SPLITS = 4;
static Effect depthEffect = Engine.Game.Content.Load<Effect>("Effects\\Shadows\\Depth");
static Effect depthLightEffect = Engine.Game.Content.Load<Effect>("Effects\\Shadows\\DepthLight");
static Effect shadowMapEffect = Engine.Game.Content.Load<Effect>("Effects\\Shadows\\ShadowMap");
static RenderTarget2D depthTexture = new RenderTarget2D(Engine.Graphics.GraphicsDevice, width, height, false, SurfaceFormat.Rg32, DepthFormat.Depth24);
static RenderTarget2D shadowMap = new RenderTarget2D(Engine.Graphics.GraphicsDevice, SHADOW_RESOLUTION * SPLITS, SHADOW_RESOLUTION, false, SurfaceFormat.Rg32, DepthFormat.Depth24);
static RenderTarget2D shadowOcclusion = new RenderTarget2D(Engine.Graphics.GraphicsDevice, width, height, false, SurfaceFormat.Color, DepthFormat.Depth24);
static Viewport splitViewport = new Viewport();
static Vector3[] frustumCornersVS = new Vector3[8];
static Vector3[] frustumCornersWS = new Vector3[8];
static Vector3[] frustumCornersLS = new Vector3[8];
static Vector3[] farFrustumCornersVS = new Vector3[4];
static Vector3[] splitFrustumCornersVS = new Vector3[8];
static OrthographicCamera[] lightCameras = new OrthographicCamera[SPLITS];
static Matrix[] lightViewProjectionMatrices = new Matrix[SPLITS];
static Vector2[] lightClipPlanes = new Vector2[SPLITS];
static float[] splitDepths = new float[SPLITS + 1];
const float nearClipOffset = 175.0f;
static bool showCascadeSplits = false;
static bool toggleJitter = true;
static Vector3 lightDirection = new Vector3(-1, -1, -1);
#region Properties
public static RenderTarget2D ShadowOcclusion
{
get { return shadowOcclusion; }
set { shadowOcclusion = value; }
}
public static bool ShowCascadeSplits
{
get { return showCascadeSplits; }
set { showCascadeSplits = value; }
}
public static Vector3 LightDirection
{
get { return lightDirection; }
set { lightDirection = value; }
}
#endregion
public static void Initialize()
{
shadowMapEffect.Parameters["ScreenResolutionSize"].SetValue(new Vector2(width, height));
shadowMapEffect.Parameters["ShadowMapSize"].SetValue(new Vector2(shadowMap.Width, shadowMap.Height));
depthEffect.Parameters["FarPlane"].SetValue(Camera.FarPlaneDistance);
splitViewport.MinDepth = 0;
splitViewport.MaxDepth = 1;
splitViewport.Width = SHADOW_RESOLUTION;
splitViewport.Height = SHADOW_RESOLUTION;
splitViewport.Y = 0;
}
private static void Render()
{
// Set our targets
Engine.Graphics.GraphicsDevice.SetRenderTarget(shadowMap);
Engine.Graphics.GraphicsDevice.Clear(ClearOptions.Target, Color.White, 1.0f, 0);
// Get corners of the main camera's bounding frustum
Matrix viewMatrix = Camera.View;
Camera.BoundingFrustum.GetCorners(frustumCornersWS);
Vector3.Transform(frustumCornersWS, ref viewMatrix, frustumCornersVS);
for (int i = 0; i < 4; i++)
{
farFrustumCornersVS = frustumCornersVS[i + 4];
}
// Calculate the cascade splits. We calculate these so that each successive
// split is larger than the previous, giving the closest split the most amount
// of shadow detail.
float N = SPLITS;
float near = 1, far = Camera.FarPlaneDistance;
splitDepths[0] = near;
splitDepths[SPLITS] = far;
const float splitConstant = 0.95f; //0.95f
for (int i = 1; i < splitDepths.Length - 1; i++)
{
splitDepths = splitConstant * near * (float)Math.Pow(far / near, i / N) + (1.0f - splitConstant) * ((near + (i / N)) * (far - near));
}
// Render our scene geometry to each split of the cascade
for (int i = 0; i < SPLITS; i++)
{
float minZ = splitDepths;
float maxZ = splitDepths[i + 1];
lightCameras = CalculateFrustum(minZ, maxZ);
RenderShadowMap(i);
}
RenderShadowOcclusion();
}
protected static OrthographicCamera CalculateFrustum(float minZ, float maxZ)
{
// Shorten the view frustum according to the shadow view distance
Matrix cameraMatrix = Camera.InverseView;
for (int i = 0; i < 4; i++)
splitFrustumCornersVS = frustumCornersVS[i + 4] * (minZ / Camera.FarPlaneDistance);
for (int i = 4; i < 8; i++)
splitFrustumCornersVS = frustumCornersVS * (maxZ / Camera.FarPlaneDistance);
Vector3.Transform(splitFrustumCornersVS, ref cameraMatrix, frustumCornersWS);
// Position the shadow-caster camera so that it's looking at the centroid,
// and backed up in the direction of the sunlight
Matrix viewMatrix = Matrix.CreateLookAt(Vector3.Zero - (lightDirection), Vector3.Zero, new Vector3(0, 1, 0));
// Determine the position of the frustum corners in light space
Vector3.Transform(frustumCornersWS, ref viewMatrix, frustumCornersLS);
// Calculate an orthographic projection by sizing a bounding box
// to the frustum coordinates in light space
Vector3 mins = frustumCornersLS[0];
Vector3 maxes = frustumCornersLS[0];
for (int i = 0; i < 8; i++)
{
if (frustumCornersLS.X > maxes.X)
maxes.X = frustumCornersLS.X;
else if (frustumCornersLS.X < mins.X)
mins.X = frustumCornersLS.X;
if (frustumCornersLS.Y > maxes.Y)
maxes.Y = frustumCornersLS.Y;
else if (frustumCornersLS.Y < mins.Y)
mins.Y = frustumCornersLS.Y;
if (frustumCornersLS.Z > maxes.Z)
maxes.Z = frustumCornersLS.Z;
else if (frustumCornersLS.Z < mins.Z)
mins.Z = frustumCornersLS.Z;
}
if (toggleJitter)
{
// 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 = (frustumCornersWS[0] - frustumCornersWS[6]).Length();
diagonalLength += 2; //Without this, the shadow map isn't big enough in the world.
float worldsUnitsPerTexel = diagonalLength / (float)SHADOW_RESOLUTION;
Vector3 borderOffset = (new Vector3(diagonalLength, diagonalLength, diagonalLength) - (maxes - mins)) * 0.5f;
maxes += borderOffset;
mins -= borderOffset;
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;
}
OrthographicCamera lightCamera = new OrthographicCamera(mins.X, maxes.X, mins.Y, maxes.Y, -maxes.Z - nearClipOffset, -mins.Z);
lightCamera.SetViewMatrix(ref viewMatrix);
return lightCamera;
}
private static void RenderShadowMap(int splitIndex)
{
splitViewport.X = splitIndex * SHADOW_RESOLUTION;
Engine.Graphics.GraphicsDevice.Viewport = splitViewport;
depthLightEffect.CurrentTechnique = depthLightEffect.Techniques["Depth"];
depthLightEffect.Parameters["ViewProjection"].SetValue(lightCameras[splitIndex].ViewProjectionMatrix);
BlockRender.Draw(depthLightEffect, lightCameras[splitIndex].BoundingFrustum);
}
/// <summary>
/// Renders a texture containing the final shadow occlusion
/// </summary>
private static void RenderShadowOcclusion()
{
Engine.Graphics.GraphicsDevice.SetRenderTarget(shadowOcclusion);
Engine.Graphics.GraphicsDevice.Clear(ClearOptions.Target, Color.White, 1.0f, 0);
// We'll use these clip planes to determine which split a pixel belongs to
for (int i = 0; i < SPLITS; i++)
{
lightClipPlanes.X = -splitDepths;
lightClipPlanes.Y = -splitDepths[i + 1];
lightCameras.GetViewProjMatrix(out lightViewProjectionMatrices);
}
shadowMapEffect.Parameters["ViewProjection"].SetValue(Camera.ViewProjection);
shadowMapEffect.Parameters["InverseView"].SetValue(Camera.InverseView);
shadowMapEffect.Parameters["LightViewProjection"].SetValue(lightViewProjectionMatrices);
shadowMapEffect.Parameters["FrustumCornersVS"].SetValue(farFrustumCornersVS);
shadowMapEffect.Parameters["ClipPlanes"].SetValue(lightClipPlanes);
shadowMapEffect.Parameters["ShadowMap"].SetValue(shadowMap);
shadowMapEffect.Parameters["DepthTexture"].SetValue(depthTexture);
shadowMapEffect.Parameters["ShowSplitColors"].SetValue(showCascadeSplits);
shadowMapEffect.CurrentTechnique.Passes[0].Apply();
DeferredRenderer.FullScreenQuad.Draw();
}
private static void CreateDepthTexture()
{
Engine.Graphics.GraphicsDevice.SetRenderTarget(depthTexture);
Engine.Graphics.GraphicsDevice.Clear(ClearOptions.Target, Color.White, 1.0f, 0);
depthEffect.Parameters["ViewProjection"].SetValue(Camera.ViewProjection);
BlockRender.Draw(depthEffect);
Engine.Graphics.GraphicsDevice.SetRenderTarget(null);
}
public static void Draw()
{
CreateDepthTexture();
Render();
//Blur.BlurShadow(Blur.shadowBlurTarg, shadowOcclusion, 0);
//Blur.BlurShadow(shadowOcclusion, Blur.shadowBlurTarg, 1);
}
/// <summary>
/// Draw the render targets to screen
/// </summary>
public static void DrawRenderTargets()
{
spriteBatch.Begin(0, BlendState.Opaque, SamplerState.PointClamp, null, null);
{
spriteBatch.Draw(shadowMap, new Rectangle(0, 0, 256, 256), Color.White);
spriteBatch.Draw(depthTexture, new Rectangle(0, 256, 256, 256), Color.White);
spriteBatch.Draw(shadowOcclusion, new Rectangle(0, 512, 256, 256), Color.White);
}
spriteBatch.End();
}
public static void HandleInput(GameTime gameTime, InputState inputState)
{
if (inputState.IsTriggered(Action.ToggleCascadeSplits)) //F7
{
showCascadeSplits = !showCascadeSplits;
}
if (inputState.IsTriggered(Action.ToggleJitter)) //J
{
toggleJitter = !toggleJitter;
}
}
}
}



float4x4 World;
float4x4 ViewProjection;
float4x4 InverseView;
static const int SPLITS = 4;
float4x4 LightViewProjection [SPLITS];
float2 ClipPlanes[SPLITS];
float2 ShadowMapSize;
float2 ScreenResolutionSize;
float3 FrustumCornersVS [4];
bool ShowSplitColors = false;
static const float SHADOW_BIAS = 0.01f;
static const float DARKEN_FACTOR = 100.0f;
texture DepthTexture;
sampler DepthTextureSampler = sampler_state
{
Texture = <DepthTexture>;
MinFilter = Point;
MagFilter = Point;
MipFilter = None;
};
texture ShadowMap;
sampler ShadowMapSampler = sampler_state
{
Texture = <ShadowMap>;
MinFilter = Point;
MagFilter = Point;
MipFilter = None;
};
float2 sampleShadowMap(float2 UV)
{
if (UV.x < 0 || UV.x > 1 || UV.y < 0 || UV.y > 1)
{
return float2(1, 1);
}
return tex2D(ShadowMapSampler, UV).rg;
}
struct VertexShaderInput
{
float4 Position : POSITION;
float3 TexCoordAndCornerIndex : TEXCOORD0;
};
struct VertexShaderOutput
{
float4 Position : POSITION;
float2 TexCoord : TEXCOORD0;
float3 FrustumCornerVS : TEXCOORD1;
};
// Vertex shader for rendering the full-screen quad used for calculating
// the shadow occlusion factor.
VertexShaderOutput VertexShaderFunction (VertexShaderInput input)
{
VertexShaderOutput output;
// Offset the position by half a pixel to correctly align texels to pixels
output.Position.x = input.Position.x - (1.0f / ScreenResolutionSize.x);
output.Position.y = input.Position.y + (1.0f / ScreenResolutionSize.y);
output.Position.z = input.Position.z;
output.Position.w = 1.0f;

// Pass along the texture coordiante and the position of the frustum corner
output.TexCoord = input.TexCoordAndCornerIndex.xy;
output.FrustumCornerVS = FrustumCornersVS[input.TexCoordAndCornerIndex.z];
return output;
}
// Pixel shader for computing the shadow occlusion factor
float4 PixelShaderFunction(VertexShaderOutput input) : COLOR0
{
// Reconstruct view-space position from the depth buffer
float pixelDepth = tex2D(DepthTextureSampler, input.TexCoord).r;
float4 position = float4(pixelDepth * input.FrustumCornerVS, 1.0f);
// Figure out which split this pixel belongs to, based on view-space depth.
float4x4 lightViewProjection = LightViewProjection[0];
float offset = 0;

float3 splitColors [4];
splitColors[0] = float3(1, 0, 0);
splitColors[1] = float3(0, 1, 0);
splitColors[2] = float3(0, 0, 1);
splitColors[3] = float3(1, 1, 0);
float3 color = splitColors[0];
int currentSplit = 0;
for (int i = 1; i < SPLITS; i++)
{
if (position.z <= ClipPlanes.x && position.z > ClipPlanes.y)
{
lightViewProjection = LightViewProjection;
offset = i / (float)SPLITS;
color = splitColors;
currentSplit = i;
}
}

// Determine the depth of the pixel with respect to the light
float4x4 inverseLVP = mul(InverseView, lightViewProjection);
float4 positionLight = mul(position, inverseLVP);

float lightDepth = (positionLight.z / positionLight.w) - SHADOW_BIAS;

// Transform from light space to shadow map texture space.
float2 shadowTexCoord = 0.5 * positionLight.xy / positionLight.w + float2(0.5f, 0.5f);
shadowTexCoord.x = shadowTexCoord.x / SPLITS + offset;
shadowTexCoord.y = 1.0f - shadowTexCoord.y;

// Offset the coordinate by half a texel so we sample it correctly
shadowTexCoord += (0.5f / ShadowMapSize);
float shadow = 1;
lightDepth += 0.01f;

if (lightDepth < 1)
{
float2 shadowMap = sampleShadowMap(shadowTexCoord);
//// Check if we're in shadow
//float lit_factor = (lightDepth < shadowMap.x);
//// Variance shadow mapping
//float E_x2 = shadowMap.y;
//float Ex_2 = shadowMap.x * shadowMap.x;
//float variance = min(max(E_x2 - Ex_2, 0.0) + 1.0f / 2000, 1);
//float m_d = (shadowMap.x - lightDepth);
//float p = variance / (variance + m_d * m_d);
//shadow = clamp(max(lit_factor, p), 0.1, 1.0f);
//Calculate the Shadow Factor
float shadowFactor = exp((DARKEN_FACTOR * 0.5f) * (shadowMap - lightDepth));
shadowFactor = clamp(shadowFactor, 0.45, 1.0);
shadow = shadowFactor;
}
if (!ShowSplitColors)
return shadow;
else
return float4(shadow + color, 1);
}
technique Shadow
{
pass p0
{
VertexShader = compile vs_3_0 VertexShaderFunction();
PixelShader = compile ps_3_0 PixelShaderFunction();
}
}



[csisy 400]

Hi!

If the problem is with the matrices, you should check this topic. It's working for me now.