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Optimize shadow rendering: static object draw state caching and low-res far shadows option #1340

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8 changes: 5 additions & 3 deletions source/LibRender2/Shadows/CascadedShadowCaster.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -23,7 +23,7 @@ public class CascadedShadowCaster
public double DepthMargin { get; set; } = 40.0;

/// <summary>Active shadow map resolution (used for texel snapping).</summary>
public int Resolution { get; set; } = 2048;
public int[] Resolutions { get; set; }

/// <summary>Per-cascade light-space VP matrices.</summary>
public Matrix4D[] LightSpaceMatrices { get; private set; }
Expand All @@ -45,10 +45,12 @@ public CascadedShadowCaster(int cascadeCount = 3)
LightSpaceMatrices = new Matrix4D[cascadeCount];
SplitDistances = new float[cascadeCount];
CascadeBiases = new float[cascadeCount];
Resolutions = new int[cascadeCount];

for (int i = 0; i < cascadeCount; i++)
{
LightSpaceMatrices[i] = Matrix4D.Identity;
Resolutions[i] = 2048;
}
}

Expand Down Expand Up @@ -120,7 +122,7 @@ public void Update(Vector3 lightDirection, Matrix4D cameraView, Matrix4D cameraP
// === Texel snapping to prevent shadow swimming on camera move ===
// Snap the light-space center to texel boundaries
// Each texel covers (2*orthoSize / Resolution) world units
double worldTexelSize = (orthoSize * 2.0) / (double)Resolution;
double worldTexelSize = (orthoSize * 2.0) / (double)Resolutions[i];

// Transform center into light view space to snap it
Vector3 centerLS = TransformPoint(center, lightView);
Expand All @@ -145,7 +147,7 @@ public void Update(Vector3 lightDirection, Matrix4D cameraView, Matrix4D cameraP

// Z-Bias: Convert physical texel size into a Depth Buffer fraction.
// This ensures we push the depth exactly enough to cure acne, but no more.
double texelWorldSize = (orthoSize * 2.0) / (double)Resolution;
double texelWorldSize = (orthoSize * 2.0) / (double)Resolutions[i];
double depthRange = zFar - zNear;
double baseBias = texelWorldSize / depthRange;
CascadeBiases[i] = (float)baseBias;
Expand Down
27 changes: 18 additions & 9 deletions source/LibRender2/Shadows/CascadedShadowMap.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -12,8 +12,11 @@ public class CascadedShadowMap : IDisposable
/// <summary>Number of cascades (shadow splits).</summary>
public int CascadeCount { get; private set; }

/// <summary>Shadow map resolution per cascade.</summary>
public int Resolution { get; private set; }
/// <summary>Base shadow map resolution.</summary>
public int BaseResolution { get; private set; }

/// <summary>Resolutions per cascade.</summary>
public int[] Resolutions { get; private set; }

/// <summary>Per-cascade FBO handles.</summary>
public int[] FBOs { get; private set; }
Expand All @@ -26,15 +29,18 @@ public class CascadedShadowMap : IDisposable
/// </summary>
/// <param name="cascadeCount">Number of cascades (typically 3 or 4).</param>
/// <param name="resolution">Resolution of each cascade's depth texture.</param>
public CascadedShadowMap(int cascadeCount = 3, int resolution = 2048)
/// <param name="lowResFarShadows">Whether to downscale resolutions for far cascades.</param>
public CascadedShadowMap(int cascadeCount = 3, int resolution = 2048, bool lowResFarShadows = true)
{
CascadeCount = cascadeCount;
Resolution = resolution;
BaseResolution = resolution;
FBOs = new int[cascadeCount];
DepthTextures = new int[cascadeCount];
Resolutions = new int[cascadeCount];

for (int i = 0; i < cascadeCount; i++)
{
Resolutions[i] = (lowResFarShadows && i > 0) ? Math.Max(128, resolution >> i) : resolution;
CreateCascade(i);
}
}
Expand All @@ -45,24 +51,27 @@ public CascadedShadowMap(int cascadeCount = 3, int resolution = 2048)
/// </summary>
/// <param name="newCascadeCount">New number of cascades.</param>
/// <param name="newResolution">New resolution per cascade.</param>
public void Resize(int newCascadeCount, int newResolution)
/// <param name="lowResFarShadows">Whether to downscale resolutions for far cascades.</param>
public void Resize(int newCascadeCount, int newResolution, bool lowResFarShadows = true)
{
// Dispose old resources
Dispose();

// Reallocate
CascadeCount = newCascadeCount;
Resolution = newResolution;
BaseResolution = newResolution;
FBOs = new int[newCascadeCount];
DepthTextures = new int[newCascadeCount];
Resolutions = new int[newCascadeCount];

for (int i = 0; i < newCascadeCount; i++)
{
Resolutions[i] = (lowResFarShadows && i > 0) ? Math.Max(128, newResolution >> i) : newResolution;
CreateCascade(i);
}

Console.WriteLine(
$"[CSM] Resized to {newCascadeCount} cascades at {newResolution}×{newResolution}");
$"[CSM] Resized to {newCascadeCount} cascades with downscaling={lowResFarShadows}");
}

private void CreateCascade(int index)
Expand All @@ -72,7 +81,7 @@ private void CreateCascade(int index)
GL.BindTexture(TextureTarget.Texture2D, DepthTextures[index]);
GL.TexImage2D(TextureTarget.Texture2D, 0,
PixelInternalFormat.DepthComponent24,
Resolution, Resolution, 0,
Resolutions[index], Resolutions[index], 0,
PixelFormat.DepthComponent, PixelType.Float, IntPtr.Zero);
GL.TexParameter(TextureTarget.Texture2D,
TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear);
Expand Down Expand Up @@ -118,7 +127,7 @@ private void CreateCascade(int index)
public void BindCascadeForWriting(int cascadeIndex)
{
GL.BindFramebuffer(FramebufferTarget.Framebuffer, FBOs[cascadeIndex]);
GL.Viewport(0, 0, Resolution, Resolution);
GL.Viewport(0, 0, Resolutions[cascadeIndex], Resolutions[cascadeIndex]);
}

/// <summary>Unbinds shadow FBO.</summary>
Expand Down
64 changes: 42 additions & 22 deletions source/LibRender2/Shadows/Shadows.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -59,11 +59,11 @@ public void Initialize()
{
if (Map == null)
{
Map = new CascadedShadowMap(cascadeCount, resolution);
Map = new CascadedShadowMap(cascadeCount, resolution, opts.LowResFarShadows);
}
else
{
Map.Resize(cascadeCount, resolution);
Map.Resize(cascadeCount, resolution, opts.LowResFarShadows);
}

if (Caster == null || cascadeCount != Caster.CascadeCount)
Expand All @@ -72,7 +72,7 @@ public void Initialize()
}

Caster.ShadowDistance = shadowDistance;
Caster.Resolution = resolution;
Caster.Resolutions = Map.Resolutions;
Caster.SplitLambda = 0.75;
Caster.DepthMargin = 150.0;

Expand Down Expand Up @@ -119,7 +119,7 @@ public void RenderPass()
// 2. Update cascade matrices
// NOTE: We pass renderer.CurrentViewMatrix here which reflects the camera's rotation.
// The Caster will use this to align the shadow frustums with the view direction.
Caster.Resolution = Map.Resolution;
Caster.Resolutions = Map.Resolutions;
if (renderer.currentOptions.ShadowDrawDistance == ShadowDistance.ViewingDistance)
{
Caster.ShadowDistance = renderer.currentOptions.ViewingDistance;
Expand Down Expand Up @@ -194,6 +194,9 @@ private void RenderFaces(IEnumerable<FaceState> faces, ref int lastVAO)
private void RenderFacesFiltered(IEnumerable<FaceState> faces, ref int lastVAO, double maxDistanceSquared)
{
Vector3 cameraPos = renderer.Camera.AbsolutePosition;
ObjectState lastObject = null;
MeshMaterial? lastMaterial = null;
int lastTextureId = -1;

foreach (var face in faces)
{
Expand All @@ -217,33 +220,50 @@ private void RenderFacesFiltered(IEnumerable<FaceState> faces, ref int lastVAO,
}
}

DepthShader.SetModelMatrix(state.ModelMatrix * renderer.Camera.TranslationMatrix);
DepthShader.SetTextureMatrix(state.TextureTranslation);

var material = face.Object.Prototype.Mesh.Materials[face.Face.Material];
if ((material.Flags & MaterialFlags.NoShadow) != 0 || material.BlendMode == MeshMaterialBlendMode.Additive)
{
continue;
}
if (material.DaytimeTexture != null && renderer.currentHost.LoadTexture(ref material.DaytimeTexture, (OpenGlTextureWrapMode)(material.WrapMode ?? OpenGlTextureWrapMode.ClampClamp)))
{
GL.ActiveTexture(TextureUnit.Texture0);
GL.BindTexture(TextureTarget.Texture2D, material.DaytimeTexture.OpenGlTextures[(int)(material.WrapMode ?? OpenGlTextureWrapMode.ClampClamp)].Name);
DepthShader.SetHasTexture(true);
}
else

// Cache and skip redundant object matrix/animation uniform updates
if (state != lastObject)
{
DepthShader.SetHasTexture(false);
DepthShader.SetModelMatrix(state.ModelMatrix * renderer.Camera.TranslationMatrix);
DepthShader.SetTextureMatrix(state.TextureTranslation);

if (state.Matricies != null && state.Matricies.Length > 0)
{
DepthShader.SetCurrentAnimationMatricies(state);
GL.BindBufferBase(BufferTarget.UniformBuffer, 0, state.MatrixBufferIndex);
}
lastObject = state;
}

DepthShader.SetAlphaCutoff(0.5f);
DepthShader.SetMaterialAlpha(material.Color.A / 255.0f);
DepthShader.SetMaterialFlags(material.Flags);

if (state.Matricies != null && state.Matricies.Length > 0)
// Cache and skip redundant material and texture state binds
if (!lastMaterial.HasValue || material != lastMaterial.Value)
{
DepthShader.SetCurrentAnimationMatricies(state);
GL.BindBufferBase(BufferTarget.UniformBuffer, 0, state.MatrixBufferIndex);
int textureId = -1;
if (material.DaytimeTexture != null && renderer.currentHost.LoadTexture(ref material.DaytimeTexture, (OpenGlTextureWrapMode)(material.WrapMode ?? OpenGlTextureWrapMode.ClampClamp)))
{
textureId = material.DaytimeTexture.OpenGlTextures[(int)(material.WrapMode ?? OpenGlTextureWrapMode.ClampClamp)].Name;
}

if (textureId != lastTextureId)
{
if (textureId != -1)
{
GL.ActiveTexture(TextureUnit.Texture0);
GL.BindTexture(TextureTarget.Texture2D, textureId);
}
DepthShader.SetHasTexture(textureId != -1);
lastTextureId = textureId;
}

DepthShader.SetAlphaCutoff(0.5f);
DepthShader.SetMaterialAlpha(material.Color.A / 255.0f);
DepthShader.SetMaterialFlags(material.Flags);
lastMaterial = material;
}

VertexArrayObject vao = (VertexArrayObject)face.Object.Prototype.Mesh.VAO;
Expand Down
31 changes: 31 additions & 0 deletions source/ObjectViewer/formOptions.cs
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Expand Up @@ -87,6 +87,26 @@ private formOptions()
comboBoxBackwards.SelectedItem = Interface.CurrentOptions.CameraMoveBackward;
checkBoxAutoReload.Checked = Interface.CurrentOptions.AutoReloadObjects;
checkBoxShadowFilterCascades.Checked = Interface.CurrentOptions.ShadowFilterCascades;

// Dynamically add LowResFarShadows checkbox
CheckBox checkBoxLowResFarShadows = new CheckBox();
checkBoxLowResFarShadows.AutoSize = true;
checkBoxLowResFarShadows.Location = new System.Drawing.Point(160, 215);
checkBoxLowResFarShadows.Name = "checkBoxLowResFarShadows";
checkBoxLowResFarShadows.Size = new System.Drawing.Size(15, 14);
checkBoxLowResFarShadows.Text = "";
checkBoxLowResFarShadows.Checked = Interface.CurrentOptions.LowResFarShadows;
checkBoxLowResFarShadows.Enabled = (Interface.CurrentOptions.ShadowResolution != ShadowMapResolution.Off);
checkBoxLowResFarShadows.UseVisualStyleBackColor = true;
this.tabPageShadows.Controls.Add(checkBoxLowResFarShadows);

Label labelLowResFarShadows = new Label();
labelLowResFarShadows.AutoSize = true;
labelLowResFarShadows.Location = new System.Drawing.Point(6, 215);
labelLowResFarShadows.Name = "labelLowResFarShadows";
labelLowResFarShadows.Size = new System.Drawing.Size(126, 13);
labelLowResFarShadows.Text = "Low-res Far Shadows:";
this.tabPageShadows.Controls.Add(labelLowResFarShadows);
}

private void InitializeSunSliders()
Expand All @@ -111,6 +131,12 @@ private void UpdateShadowControlsEnabled()

trackBarSunElevation.Enabled = enabled;
checkBoxShadowFilterCascades.Enabled = enabled;

CheckBox checkBoxLowResFarShadows = this.tabPageShadows.Controls["checkBoxLowResFarShadows"] as CheckBox;
if (checkBoxLowResFarShadows != null)
{
checkBoxLowResFarShadows.Enabled = enabled;
}
}

private void comboBoxShadowResolution_SelectedIndexChanged(object sender, EventArgs e)
Expand Down Expand Up @@ -281,6 +307,11 @@ private void CloseButton_Click(object sender, EventArgs e)
Interface.CurrentOptions.ShadowBias = (double)numericUpDownShadowBias.Value;
Interface.CurrentOptions.ShadowNormalBias = (double)numericUpDownShadowNormalBias.Value;
Interface.CurrentOptions.ShadowFilterCascades = checkBoxShadowFilterCascades.Checked;
CheckBox checkBoxLowResFarShadows = this.tabPageShadows.Controls["checkBoxLowResFarShadows"] as CheckBox;
if (checkBoxLowResFarShadows != null)
{
Interface.CurrentOptions.LowResFarShadows = checkBoxLowResFarShadows.Checked;
}

Interface.CurrentOptions.Save(Path.CombineFile(Program.FileSystem.SettingsFolder, "1.5.0/options_ov.cfg"));
Program.RefreshObjects();
Expand Down
2 changes: 2 additions & 0 deletions source/OpenBVE/System/Options.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -326,6 +326,7 @@ public override void Save(string fileName)
Builder.AppendLine("shadowbias = " + ShadowBias.ToString(Culture));
Builder.AppendLine("shadownormalbias = " + ShadowNormalBias.ToString(Culture));
Builder.AppendLine("shadowfiltercascades = " + (ShadowFilterCascades ? "true" : "false"));
Builder.AppendLine("lowresfarshadows = " + (LowResFarShadows ? "true" : "false"));
Builder.AppendLine("fpslimit = " + FPSLimit.ToString(Culture));
Builder.AppendLine();
Builder.AppendLine("[objectOptimization]");
Expand Down Expand Up @@ -540,6 +541,7 @@ internal static void LoadOptions()
block.TryGetValue(OptionsKey.ShadowNormalBias, ref CurrentOptions.ShadowNormalBias);
if (CurrentOptions.ShadowNormalBias < 0.0) CurrentOptions.ShadowNormalBias = 0.0;
block.GetValue(OptionsKey.ShadowFilterCascades, out Interface.CurrentOptions.ShadowFilterCascades);
block.GetValue(OptionsKey.LowResFarShadows, out Interface.CurrentOptions.LowResFarShadows);
block.GetValue(OptionsKey.FPSLimit, out CurrentOptions.FPSLimit);
if (CurrentOptions.FPSLimit < 0)
{
Expand Down
6 changes: 6 additions & 0 deletions source/OpenBVE/UserInterface/formMain.Options.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -55,6 +55,12 @@ private void comboboxShadowResolution_SelectedIndexChanged(object sender, EventA
updownShadowNormalBias.Enabled = shadowEnabled;
checkboxShadowFilterCascades.Enabled = shadowEnabled;

CheckBox checkboxLowResFarShadows = this.groupboxShadows.Controls["checkboxLowResFarShadows"] as CheckBox;
if (checkboxLowResFarShadows != null)
{
checkboxLowResFarShadows.Enabled = shadowEnabled;
}

if (!shadowEnabled)
{
// Visual hint: grey out the strength label
Expand Down
19 changes: 19 additions & 0 deletions source/OpenBVE/UserInterface/formMain.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -499,6 +499,20 @@ private void formMain_Load(object sender, EventArgs e)
checkboxShadowFilterCascades.Checked = Interface.CurrentOptions.ShadowFilterCascades;
// Enable/disable shadow sub-controls based on resolution setting
bool shadowEnabled = Interface.CurrentOptions.ShadowResolution != ShadowMapResolution.Off;

// Dynamically add LowResFarShadows checkbox
this.groupboxShadows.Height = 265;
CheckBox checkboxLowResFarShadows = new CheckBox();
checkboxLowResFarShadows.AutoSize = true;
checkboxLowResFarShadows.Location = new System.Drawing.Point(8, 238);
checkboxLowResFarShadows.Name = "checkboxLowResFarShadows";
checkboxLowResFarShadows.Size = new System.Drawing.Size(150, 17);
checkboxLowResFarShadows.Text = "Low-res Far Shadows";
checkboxLowResFarShadows.Checked = Interface.CurrentOptions.LowResFarShadows;
checkboxLowResFarShadows.Enabled = shadowEnabled;
checkboxLowResFarShadows.UseVisualStyleBackColor = true;
this.groupboxShadows.Controls.Add(checkboxLowResFarShadows);

comboboxShadowDistance.Enabled = shadowEnabled;
comboboxShadowCascades.Enabled = shadowEnabled;
checkboxShadowFilterCascades.Enabled = shadowEnabled;
Expand Down Expand Up @@ -1264,6 +1278,11 @@ private void formMain_FormClosing()
Interface.CurrentOptions.ShadowBias = (double)updownShadowBias.Value;
Interface.CurrentOptions.ShadowNormalBias = (double)updownShadowNormalBias.Value;
Interface.CurrentOptions.ShadowFilterCascades = checkboxShadowFilterCascades.Checked;
CheckBox checkboxLowResFarShadows = this.groupboxShadows.Controls["checkboxLowResFarShadows"] as CheckBox;
if (checkboxLowResFarShadows != null)
{
Interface.CurrentOptions.LowResFarShadows = checkboxLowResFarShadows.Checked;
}
Interface.CurrentOptions.GameMode = (GameMode)comboboxMode.SelectedIndex;
Interface.CurrentOptions.BlackBox = checkboxBlackBox.Checked;
Interface.CurrentOptions.LoadingSway = checkBoxLoadingSway.Checked;
Expand Down
1 change: 1 addition & 0 deletions source/OpenBveApi/System/BaseOptions.OptionsKey.cs
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Expand Up @@ -57,6 +57,7 @@ public enum OptionsKey
ShadowBias,
ShadowNormalBias,
ShadowFilterCascades,
LowResFarShadows,
LightAzimuth,

LightElevation,
Expand Down
2 changes: 2 additions & 0 deletions source/OpenBveApi/System/BaseOptions.cs
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Expand Up @@ -96,6 +96,8 @@ public abstract class BaseOptions
public double ShadowNormalBias = 2.0;
/// <summary>Whether to filter shadow casters per cascade to improve performance.</summary>
public bool ShadowFilterCascades = true;
/// <summary>Whether to downscale far cascade shadow map resolutions to improve performance.</summary>
public bool LowResFarShadows = true;


/// <summary>The sun azimuth in degrees</summary>
Expand Down
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