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Optimize FoliageInstance size to cut down memory by and reduce cache misses when drawing foliage

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This commit is contained in:
Wojciech Figat
2026-04-27 22:54:11 +02:00
parent 4fd7f51fdf
commit bf9a015959
2 changed files with 57 additions and 45 deletions
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Source/Engine/Foliage/Foliage.cpp
+36 -32
View File
@@ -147,7 +147,6 @@ void Foliage::DrawInstance(DrawContext& context, FoliageInstance& instance, Mode
if (!e)
{
e = &result.Add(key, BatchedDrawCall(context.RenderContext.List))->Value;
ASSERT_LOW_LAYER(key.Mat);
e->DrawCall.Material = key.Mat;
e->DrawCall.Surface.Lightmap = EnumHasAnyFlags(_staticFlags, StaticFlags::Lightmap) && _scene ? _scene->LightmapsData.GetReadyLightmap(key.Lightmap) : nullptr;
e->DrawCall.Surface.GeometrySize = key.Geo->GetBox().GetSize();
@@ -156,7 +155,8 @@ void Foliage::DrawInstance(DrawContext& context, FoliageInstance& instance, Mode
// Add instance to the draw batch
auto& instanceData = e->Instances.AddOne();
Matrix world;
const Transform transform = _transform.LocalToWorld(instance.Transform);
Transform transform;
_transform.LocalToWorld(instance.Transform, transform);
const Float3 translation = transform.Translation - context.ViewOrigin;
Matrix::Transformation(transform.Scale, transform.Orientation, translation, world);
constexpr float worldDeterminantSign = 1.0f;
@@ -203,45 +203,45 @@ void Foliage::DrawCluster(DrawContext& context, FoliageCluster* cluster, DrawCal
context.RenderContext.View.CullingFrustum.Intersects(sphere) &&
RenderTools::ComputeBoundsScreenRadiusSquared(sphere.Center, (float)sphere.Radius, context.RenderContext.View) * context.ViewScreenSizeSq >= context.MinObjectPixelSizeSq)
{
const auto modelFrame = instance.DrawState.PrevFrame + 1;
const auto modelFrame = instance.DrawStatePrevFrame + 1;
// Select a proper LOD index (model may be culled)
int32 lodIndex = RenderTools::ComputeModelLOD(model, sphere.Center, (float)sphere.Radius, context.RenderContext);
if (lodIndex == -1)
{
// Handling model fade-out transition
if (modelFrame == frame && instance.DrawState.PrevLOD != -1)
if (modelFrame == frame && instance.DrawStatePrevLOD != -1)
{
if (transitionLOD)
{
// Check if start transition
if (instance.DrawState.LODTransition == 255)
if (instance.DrawStateLODTransition == 255)
{
instance.DrawState.LODTransition = 0;
instance.DrawStateLODTransition = 0;
}
RenderTools::UpdateModelLODTransition(instance.DrawState.LODTransition);
RenderTools::UpdateModelLODTransition(instance.DrawStateLODTransition);
// Check if end transition
if (instance.DrawState.LODTransition == 255)
if (instance.DrawStateLODTransition == 255)
{
instance.DrawState.PrevLOD = lodIndex;
instance.DrawStatePrevLOD = lodIndex;
}
else
{
const auto prevLOD = model->ClampLODIndex(instance.DrawState.PrevLOD);
const float normalizedProgress = static_cast<float>(instance.DrawState.LODTransition) * (1.0f / 255.0f);
const auto prevLOD = model->ClampLODIndex(instance.DrawStatePrevLOD);
const float normalizedProgress = static_cast<float>(instance.DrawStateLODTransition) * (1.0f / 255.0f);
DrawInstance(context, instance, model, prevLOD, normalizedProgress, drawCallsLists, result);
}
}
else if (instance.DrawState.LODTransition < 255)
else if (instance.DrawStateLODTransition < 255)
{
const auto prevLOD = model->ClampLODIndex(instance.DrawState.PrevLOD);
const float normalizedProgress = static_cast<float>(instance.DrawState.LODTransition) * (1.0f / 255.0f);
const auto prevLOD = model->ClampLODIndex(instance.DrawStatePrevLOD);
const float normalizedProgress = static_cast<float>(instance.DrawStateLODTransition) * (1.0f / 255.0f);
DrawInstance(context, instance, model, prevLOD, normalizedProgress, drawCallsLists, result);
}
}
instance.DrawState.PrevFrame = frame;
instance.DrawStatePrevFrame = frame;
continue;
}
lodIndex += context.RenderContext.View.ModelLODBias;
@@ -253,42 +253,42 @@ void Foliage::DrawCluster(DrawContext& context, FoliageCluster* cluster, DrawCal
if (modelFrame == frame)
{
// Check if start transition
if (instance.DrawState.PrevLOD != lodIndex && instance.DrawState.LODTransition == 255)
if (instance.DrawStatePrevLOD != lodIndex && instance.DrawStateLODTransition == 255)
{
instance.DrawState.LODTransition = 0;
instance.DrawStateLODTransition = 0;
}
RenderTools::UpdateModelLODTransition(instance.DrawState.LODTransition);
RenderTools::UpdateModelLODTransition(instance.DrawStateLODTransition);
// Check if end transition
if (instance.DrawState.LODTransition == 255)
if (instance.DrawStateLODTransition == 255)
{
instance.DrawState.PrevLOD = lodIndex;
instance.DrawStatePrevLOD = lodIndex;
}
}
// Check if there was a gap between frames in drawing this model instance
else if (modelFrame < frame || instance.DrawState.PrevLOD == -1)
else if (modelFrame < frame || instance.DrawStatePrevLOD == -1)
{
// Reset state
instance.DrawState.PrevLOD = lodIndex;
instance.DrawState.LODTransition = 0;
instance.DrawStatePrevLOD = lodIndex;
instance.DrawStateLODTransition = 0;
}
}
// Draw
if (instance.DrawState.PrevLOD == lodIndex)
if (instance.DrawStatePrevLOD == lodIndex)
{
DrawInstance(context, instance, model, lodIndex, 0.0f, drawCallsLists, result);
}
else if (instance.DrawState.PrevLOD == -1)
else if (instance.DrawStatePrevLOD == -1)
{
const float normalizedProgress = static_cast<float>(instance.DrawState.LODTransition) * (1.0f / 255.0f);
const float normalizedProgress = static_cast<float>(instance.DrawStateLODTransition) * (1.0f / 255.0f);
DrawInstance(context, instance, model, lodIndex, 1.0f - normalizedProgress, drawCallsLists, result);
}
else
{
const auto prevLOD = model->ClampLODIndex(instance.DrawState.PrevLOD);
const float normalizedProgress = static_cast<float>(instance.DrawState.LODTransition) * (1.0f / 255.0f);
const auto prevLOD = model->ClampLODIndex(instance.DrawStatePrevLOD);
const float normalizedProgress = static_cast<float>(instance.DrawStateLODTransition) * (1.0f / 255.0f);
DrawInstance(context, instance, model, prevLOD, normalizedProgress, drawCallsLists, result);
DrawInstance(context, instance, model, lodIndex, normalizedProgress - 1.0f, drawCallsLists, result);
}
@@ -296,7 +296,7 @@ void Foliage::DrawCluster(DrawContext& context, FoliageCluster* cluster, DrawCal
//DebugDraw::DrawSphere(instance.Bounds, Color::YellowGreen);
if (transitionLOD)
instance.DrawState.PrevFrame = frame;
instance.DrawStatePrevFrame = frame;
}
}
}
@@ -350,6 +350,8 @@ void Foliage::DrawCluster(DrawContext& context, FoliageCluster* cluster, Mesh::D
Matrix::Transformation(transform.Scale, transform.Orientation, translation, world);
// Disable motion blur
GeometryDrawStateData drawState;
drawState.PrevWorld = world;
instance.DrawState.PrevWorld = world;
// Draw model
@@ -357,7 +359,7 @@ void Foliage::DrawCluster(DrawContext& context, FoliageCluster* cluster, Mesh::D
draw.LightmapUVs = &instance.Lightmap.UVsArea;
draw.Buffer = &type.Entries;
draw.World = &world;
draw.DrawState = &instance.DrawState;
draw.DrawState = &drawState;
draw.Bounds = sphere;
draw.PerInstanceRandom = instance.Random;
draw.DrawModes = type._drawModes;
@@ -366,7 +368,7 @@ void Foliage::DrawCluster(DrawContext& context, FoliageCluster* cluster, Mesh::D
//DebugDraw::DrawSphere(instance.Bounds, Color::YellowGreen);
instance.DrawState.PrevFrame = frame;
instance.DrawStatePrevFrame = frame;
}
}
}
@@ -1263,6 +1265,8 @@ void Foliage::Draw(RenderContext& renderContext)
Matrix world;
const Transform transform = _transform.LocalToWorld(instance.Transform);
renderContext.View.GetWorldMatrix(transform, world);
GeometryDrawStateData drawState;
drawState.PrevWorld = world;
Mesh::DrawInfo draw;
draw.Flags = GetStaticFlags();
draw.LODBias = 0;
@@ -1273,7 +1277,7 @@ void Foliage::Draw(RenderContext& renderContext)
draw.LightmapUVs = &instance.LightmapUVsArea;
draw.Buffer = &type.Entries;
draw.World = &world;
draw.DrawState = &instance.DrawState;
draw.DrawState = &drawState;
draw.Deformation = nullptr;
draw.Bounds = instance.Bounds;
draw.PerInstanceRandom = instance.Random;
Source/Engine/Foliage/FoliageInstance.h
+21 -13
View File
@@ -5,15 +5,13 @@
#include "Engine/Core/Math/Transform.h"
#include "Engine/Core/Math/BoundingSphere.h"
#include "Engine/Core/Math/Half.h"
#include "Engine/Renderer/DrawCall.h"
#include "Engine/Level/Scene/Lightmap.h"
/// <summary>
/// Foliage instanced mesh instance. Packed data with very little of logic. Managed by the foliage chunks and foliage actor itself.
/// </summary>
API_STRUCT(NoPod) struct FLAXENGINE_API FoliageInstance
API_STRUCT(NoPod, NoDefault) struct FLAXENGINE_API FoliageInstance
{
DECLARE_SCRIPTING_TYPE_NO_SPAWN(FoliageInstance);
DECLARE_SCRIPTING_TYPE_MINIMAL(FoliageInstance);
/// <summary>
/// The local-space transformation of the mesh relative to the foliage actor.
@@ -21,19 +19,34 @@ API_STRUCT(NoPod) struct FLAXENGINE_API FoliageInstance
API_FIELD() Transform Transform;
/// <summary>
/// The model drawing state.
/// The cached instance bounds (in world space).
/// </summary>
GeometryDrawStateData DrawState;
API_FIELD() BoundingSphere Bounds;
/// <summary>
/// The previous frame index. In sync with Engine::FrameCount used to detect new frames and rendering gaps to reset state.
/// </summary>
uint64 DrawStatePrevFrame = 0;
/// <summary>
/// The foliage type index. Foliage types are hold in foliage actor and shared by instances using the same model.
/// </summary>
API_FIELD() int32 Type;
API_FIELD() uint16 Type;
/// <summary>
/// The lightmap index for the foliage instance. -1 if unused.
/// </summary>
int8 LightmapTextureIndex;
int8 LightmapTextureIndex = -1;
/// <summary>
/// The previous frame model LOD index used. It's locked during LOD transition to cache the transition start LOD.
/// </summary>
char DrawStatePrevLOD = -1;
/// <summary>
/// The LOD transition timer.
/// </summary>
byte DrawStateLODTransition = 255;
/// <summary>
/// The per-instance random value from range [0;1].
@@ -45,11 +58,6 @@ API_STRUCT(NoPod) struct FLAXENGINE_API FoliageInstance
/// </summary>
float CullDistance;
/// <summary>
/// The cached instance bounds (in world space).
/// </summary>
API_FIELD() BoundingSphere Bounds;
/// <summary>
/// Lightmap UVs area that entry occupies (packed Rectangle into Half4).
/// </summary>