ue4.24调通了shader文档

最新推荐文章于 2024-10-17 12:54:09 发布

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最新推荐文章于 2024-10-17 12:54:09 发布 · 892 阅读

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CC 4.0 BY-SA版权

本文详细介绍了在UE4中实现镜头畸变UV生成的过程，包括如何利用顶点和像素着色器直接计算畸变和非畸变UV位移，并将其存储到纹理的红绿通道中。文章还涉及了蓝图的熟悉运用、渲染到纹理的机制、虚拟目录的使用以及源码和插件的参考，特别强调了与镜头畸变模型相关的结构体和函数的定义与调用。

先上图，

有几个感慨：

1，ue4文档不与时俱进，所以还要看源码或者例子。这个就是按照源码插件依葫芦画瓢进行的

2，shader加载时机，按照build.cs进行，要不会崩溃，启动编辑器之后才加载

3.蓝图要熟，因为要给蓝图用，所以，还要学学。

4，渲染到纹理是每帧进行，一开始忘了，所以没出来结果,event tick()

5，需要虚拟目录了，

6，虚拟目录后，vs和Ps找的shader文件，也不是真实的目录，而是逻辑层次(这点存疑，还需要看看）

IMPLEMENT_SHADER_TYPE(, FLensDistortionUVGenerationVS, TEXT("/Plugin/Foo/Private/UVGeneration.usf"), TEXT("MainVS"), SF_Vertex)
IMPLEMENT_SHADER_TYPE(, FLensDistortionUVGenerationPS, TEXT("/Plugin/Foo/Private/UVGeneration.usf"), TEXT("MainPS"), SF_Pixel)

先看看存放目录

磨蹭了很长时间，发现蓝图不熟，以后还得慢慢学，

暴露给蓝图使用，类要用category标识，比如

       UFUNCTION(BlueprintPure, Category = "findMyFoo")
       static void GetUndistortOverscanFactor(
           const FFooCameraModel& CameraModel,
           float DistortedHorizontalFOV,
           float DistortedAspectRatio,
           float& UndistortOverscanFactor);

这个方法的Catetory是"findMyFoo"，在蓝图中，输入"find"及以后的就可以智能弹出,能够找到。

但是结构体很诡异，我一开始用FooCameraModel,结果显示的ooCameraModel,用FFooCameraModel，才显示FooCameraModel,第一个F被吃了。
struct FOO_API FFooCameraModel
{

}..

generate.h生成时，要用.uproject文件

另外，为了显示是否正确生成，在ps上直接赋值红色。

蓝图设置上，

最后，直接上源码了

Foo.h

#pragma once

#include "CoreMinimal.h"
#include "Modules/ModuleInterface.h"
#include "Modules/ModuleManager.h"

/**
* The public interface to this module
*/
class ILensDistortion : public IModuleInterface
{

public:

   /**
   * Singleton-like access to this module's interface. This is just for convenience!
   * Beware of calling this during the shutdown phase, though. Your module might have been unloaded already.
   *
   * @return Returns singleton instance, loading the module on demand if needed
   */
   static inline ILensDistortion& Get()
   {
       return FModuleManager::LoadModuleChecked< ILensDistortion >("Foo");
   }

   /**
   * Checks to see if this module is loaded and ready. It is only valid to call Get() if IsAvailable() returns true.
   *
   * @return True if the module is loaded and ready to use
   */
   static inline bool IsAvailable()
   {
       return FModuleManager::Get().IsModuleLoaded("Foo");
   }
};

Foo.cpp

#include "Foo.h"
#include "CoreMinimal.h"
#include "Modules/ModuleManager.h"
#include "Interfaces/IPluginManager.h"
#include "Misc/Paths.h"
#include "ShaderCore.h"

class FLensDistortion : public ILensDistortion
{
   /** IModuleInterface implementation */
   virtual void StartupModule() override;
   virtual void ShutdownModule() override;
};

IMPLEMENT_MODULE(FLensDistortion, Foo)

void FLensDistortion::StartupModule()
{
FString PluginShaderDir = FPaths::Combine(IPluginManager::Get().FindPlugin(TEXT("Foo"))->GetBaseDir(), TEXT("Shaders"));
AddShaderSourceDirectoryMapping(TEXT("/Plugin/Foo"), PluginShaderDir);
}

void FLensDistortion::ShutdownModule()
{
// This function may be called during shutdown to clean up your module. For modules that support dynamic reloading,
// we call this function before unloading the module.
}

FooBlueprintFunctionLibrary.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "UObject/ObjectMacros.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "FooCameraModule.h"
#include "FooBlueprintFunctionLibrary.generated.h"

/**
*
*/

UCLASS(MinimalAPI, meta = (ScriptName = "FooFunctionLibrary"))
class UFooBlueprintFunctionLibrary : public UBlueprintFunctionLibrary
{
GENERATED_UCLASS_BODY()

       /** Returns the overscan factor required for the undistort rendering to avoid unrendered distorted pixels. */
       UFUNCTION(BlueprintPure, Category = "findMyFoo")
       static void GetUndistortOverscanFactor(
           const FFooCameraModel& CameraModel,
           float DistortedHorizontalFOV,
           float DistortedAspectRatio,
           float& UndistortOverscanFactor);

   /** Draws UV displacement map within the output render target.
   * - Red & green channels hold the distortion displacement;
   * - Blue & alpha channels hold the undistortion displacement.
   * @param DistortedHorizontalFOV The desired horizontal FOV in the distorted render.
   * @param DistortedAspectRatio The desired aspect ratio of the distorted render.
   * @param UndistortOverscanFactor The factor of the overscan for the undistorted render.
   * @param OutputRenderTarget The render target to draw to. Don't necessarily need to have same resolution or aspect ratio as distorted render.
   * @param OutputMultiply The multiplication factor applied on the displacement.
   * @param OutputAdd Value added to the multiplied displacement before storing into the output render target.
   */
   UFUNCTION(BlueprintCallable, Category = "findMyFoo", meta = (WorldContext = "WorldContextObject"))
       static void DrawUVDisplacementToRenderTarget(
           const UObject* WorldContextObject,
           const FFooCameraModel& CameraModel,
           float DistortedHorizontalFOV,
           float DistortedAspectRatio,
           float UndistortOverscanFactor,
           class UTextureRenderTarget2D* OutputRenderTarget,
           float OutputMultiply = 0.5,
           float OutputAdd = 0.5
       );

   /* Returns true if A is equal to B (A == B) */
   UFUNCTION(BlueprintPure, meta = (DisplayName = "Equal (FFooCameraModel)", CompactNodeTitle = "==", Keywords = "== equal"), Category = "findMyFoo")
       static bool EqualEqual_CompareFFooCameraModels(
           const FFooCameraModel& A,
           const FFooCameraModel& B)
   {
       return A == B;
   }

   /* Returns true if A is not equal to B (A != B) */
   UFUNCTION(BlueprintPure, meta = (DisplayName = "NotEqual (FFooCameraModel)", CompactNodeTitle = "!=", Keywords = "!= not equal"), Category = "findMyFoo")
       static bool NotEqual_CompareFFooCameraModels(
           const FFooCameraModel& A,
           const FFooCameraModel& B)
   {
       return A != B;
   }
};

FooBlueprintFunctionLibrary.cpp

// Fill out your copyright notice in the Description page of Project Settings.

#include "FooBlueprintFunctionLibrary.h"

UFooBlueprintFunctionLibrary::UFooBlueprintFunctionLibrary(const FObjectInitializer& ObjectInitializer)
: Super(ObjectInitializer)
{ }

// static
void UFooBlueprintFunctionLibrary::GetUndistortOverscanFactor(
   const FFooCameraModel& CameraModel,
   float DistortedHorizontalFOV,
   float DistortedAspectRatio,
   float& UndistortOverscanFactor)
{