ofxDeferredShading

Here is demo.

Concept

Modern OpenGL compatible

I was satisfied with ofxPostPrpcessing long time, which is fabulous and has so many beautiful vfx in it. I really appreciate the author and contributors. But there is little problem when I use my own shaders with it. It is not written in "modern" shader version so cannot coexist with the "programmble renderer". At this moment, however we have to decide to abandon legacy but helpful functions including ofLight, glBegin()-glEnd()...

Photo-realistic in Real-time

And the addon mentioned above has only few effects for photo-real purpose such like "casting shadow". So I decided to reproduce and regather PostProcesses focusing "photo-real" rendering and compatible in modern version.

Now it contains

• Edge detection
• Multiple point-lights with attenuation
• Casting shadow with directional light
  • plus Volumetric light using shadow map
• SSAO: Screen Space Ambient Occlusion
• Depth of Field
  • plus Foreground blurring
  • plus Bokeh point rendering
• Bloom (Kawase's)
• Volumetric fog

Support

• openFrameworks 0.10.0~ (using glm library)

Usage

• specify modern version of OpenGL in main.cpp

int main( ){
    ofGLWindowSettings settings;
    settings.setGLVersion(4, 1); // now we use OpenGL 4.1
    settings.setSize(1024, 768);

    ofCreateWindow(settings);
    ofRunApp(new ofApp());
}

• declare instances in ofApp.h
  • it's safer to use std::shared_ptr

// declare in ofApp.h
ofxDeferredProcessing deferred;
ofPtr<ofxDeferred::SsaoPass> ssao;
ofPtr<ofxDeferred::PointLightPass> points;
ofPtr<ofxDeferred::ShadowLightPass> shadow;
ofPtr<ofxDeferred::HdrBloomPass> bloom;
...

• init and create Passes in ofApp::setup(), and get reference of Passes

deferred.init(ofGetWidth(), ofGetHeight());
ssao = deferred.createPass<ofxDeferred::SsaoPass>();
points = deferred.createPass<ofxDeferred::PointLightPass>();
shadow = deferred.createPass<ofxDeferred::ShadowLightPass>();    
bloom = deferred.createPass<ofxDeferred::HdrBloomPass>();

• set parameters via reference

ssao->setOcculusionRadius(5.0);
ssao->setDarkness(1.0);

• draw objects between begin() and end().

• If you want to HDR color, just specify vertex color bright enough (can be more than 1.0) through ofFloatColor's parameters.

• if you want to use cast shadow (ShadowLightPass), you need another draw call for shadow map.

  // for shadow map
  shadowLightPass->beginShadowMap();
      drawObjs(); // draw something
      lightPass->drawLights(); // draw light bulbs
  shadowLightPass->endShadowMap();
  
  // for rendering pass
  deferred.begin(cam);
      drawObjs(); // exactly the same call above
      lightPass->drawLights();
  deferred.end();

• Also, you can use own shader for mesh rendering. In this case, you need to write pixel data into color buffer properly like below.

#version 400

uniform int shadowFlag;

in vec4 vPos;
in vec4 vNormal;
in vec4 vColor;
in float vDepth;

layout (location = 0) out vec4 outputColor0; // Color
layout (location = 1) out vec4 outputColor1; // Position
layout (location = 2) out vec4 outputColor2; // Normal and Depth

void main(){

    if (shadowFlag == 1) {
        outputColor0.r = vDepth;
        outputColor0.a = 1.;
    } else {
        outputColor0 = vColor;
        outputColor1 = vPos;
        outputColor2 = vec4(vNormal.xyz, vDepth);
    }

}

Reference

Render Pass

• Basic architecture and "RenderPass" is quoted from neilmendoza/ofxPostProcessing.
• GBuffer design from hanasaan/ofxDeferredProcessing

Effects

• Defocus blur including foreground blurring from GPU Gems 3
• Bokeh rendering from OpenGL Insights
• Point light with attenuation from jacres/of-DeferredRendering
• Shadow Mapping from Learn OpenGL
• Screen Space Ambient occlusion from Learn OpenGL
• Kawase's bloom from Intel's article
• Volumetric lighting from Alexandre Pestana

Author

Ayumu Nagamatsu