protected unsafe override void DoInitialize()
{
base.DoInitialize();
// pbr: generate a 2D LUT from the BRDF equations used.
// then re-configure capture framebuffer object and render screen-space quad with BRDF shader.
// pbr: setup framebuffer
var captureFBO = new Framebuffer(512, 512);
captureFBO.Bind();
var captureRBO = new Renderbuffer(512, 512, GL.GL_DEPTH_COMPONENT24);
captureFBO.Attach(FramebufferTarget.Framebuffer, captureRBO, AttachmentLocation.Depth);
captureFBO.Attach(FramebufferTarget.Framebuffer, this.texBRDF, 0u);
captureFBO.CheckCompleteness();
captureFBO.Unbind();
RenderMethod method = this.RenderUnit.Methods[0];
ViewportSwitch viewportSwitch = new ViewportSwitch(0, 0, 512, 512);
viewportSwitch.On();
captureFBO.Bind();
GL.Instance.Clear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
method.Render();
captureFBO.Unbind();
viewportSwitch.Off();
captureFBO.Dispose();
this.texBRDF.GetImage(512, 512).Save(string.Format("texBRDF.png"));
}
protected unsafe override void DoInitialize()
{
base.DoInitialize();
// pbr: run a quasi monte-carlo simulation on the environment lighting to create a prefilter (cube)map.
const uint maxMipLevels = 5;
var viewport = new ViewportSwitch();
for (int mip = 0; mip < maxMipLevels; ++mip)
{
// reisze framebuffer according to mip-level size.
int mipWidth = (int)(128 * Math.Pow(0.5, mip));
int mipHeight = (int)(128 * Math.Pow(0.5, mip));
var captureFBO = new Framebuffer(mipWidth, mipHeight);
captureFBO.Bind();
var captureRBO = new Renderbuffer(mipWidth, mipHeight, GL.GL_DEPTH_COMPONENT24);
captureFBO.Attach(FramebufferTarget.Framebuffer, captureRBO, AttachmentLocation.Depth);
captureFBO.CheckCompleteness();
captureFBO.Unbind();
viewport.Width = mipWidth; viewport.Height = mipHeight;
viewport.On();
// NOTE: I added '/ 10' to make it a clearer visual effect.
float roughness = (float)mip / (float)(maxMipLevels - 1) / 5;
RenderMethod method = this.RenderUnit.Methods[0];
ShaderProgram program = method.Program;
program.SetUniform("roughness", roughness);
program.SetUniform("projection", captureProjection);
program.SetUniform("environmentMap", this.envCubemap);
for (uint i = 0; i < 6; ++i)
{
program.SetUniform("view", captureViews[i]);
CubemapFace face = (CubemapFace)(GL.GL_TEXTURE_CUBE_MAP_POSITIVE_X + i);
uint location = 0;
//int level = 0;
captureFBO.Bind();
captureFBO.Attach(FramebufferTarget.Framebuffer, location, face, this.prefilterMap, mip);
captureFBO.CheckCompleteness();
captureFBO.Unbind();
captureFBO.Bind();
GL.Instance.Clear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
method.Render();
captureFBO.Unbind();
this.prefilterMap.GetImage(face, mipWidth, mipHeight, mip).Save(string.Format("prefilter.{0}.mip{1}.png", face, mip));
}
viewport.Off();
captureFBO.Dispose();
}
}
protected unsafe override void DoInitialize()
{
base.DoInitialize();
ViewportSwitch viewportSwitch = new ViewportSwitch(0, 0, 512, 512);
// pbr: setup framebuffer
var captureFBO = new Framebuffer(512, 512);
captureFBO.Bind();
var captureRBO = new Renderbuffer(512, 512, GL.GL_DEPTH_COMPONENT24);
captureFBO.Attach(FramebufferTarget.Framebuffer, captureRBO, AttachmentLocation.Depth);
captureFBO.CheckCompleteness();
captureFBO.Unbind();
// pbr: convert HDR equirectangular environment map to cubemap equivalent
RenderMethod method = this.RenderUnit.Methods[0];
ShaderProgram program = method.Program;
program.SetUniform("equirectangularMap", this.texHDR);
program.SetUniform("projection", captureProjection);
viewportSwitch.On();
for (uint i = 0; i < 6; ++i)
{
program.SetUniform("view", captureViews[i]);
CubemapFace face = (CubemapFace)(GL.GL_TEXTURE_CUBE_MAP_POSITIVE_X + i);
uint location = 0;
int level = 0;
captureFBO.Bind();
captureFBO.Attach(FramebufferTarget.Framebuffer, location, face, this.environmentMap, level);
captureFBO.CheckCompleteness();
captureFBO.Unbind();
captureFBO.Bind();
GL.Instance.Clear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
method.Render();
captureFBO.Unbind();
this.environmentMap.GetImage(face, 512, 512).Save(string.Format("texEnvCubemap.{0}.mip{1}.png", face, 0));
}
viewportSwitch.Off();
captureFBO.Dispose();
this.environmentMap.Bind();
glGenerateMipmap(GL.GL_TEXTURE_CUBE_MAP);
this.environmentMap.Unbind();
}
protected override void DoInitialize()
{
// init textures.
this.envCubeMap = LoadEnvCubeMap();
this.irradianceMap = LoadIrradianceMap();
this.prefliterMap = LoadPrefliterMap();
this.brdfLUTTexture = LoadBRDFTexture();
//this.hdrTexture = LoadHdrEnvironmentMap(@"Texture\hdr\newport_loft.hdr");
this.hdrTexture = LoadHDRTexture(@"Texture\hdr\newport_loft.hdr");
//{
// Bitmap bitmap = LoadHdrFormFreeImage(@"Texture\hdr\newport_loft.hdr");
// var storage = new TexImageBitmap(bitmap, GL.GL_RGB16F);
// var texture = new Texture(storage,
// new TexParameteri(TexParameter.PropertyName.TextureWrapS, (int)GL.GL_CLAMP_TO_EDGE),
// new TexParameteri(TexParameter.PropertyName.TextureWrapT, (int)GL.GL_CLAMP_TO_EDGE),
// new TexParameteri(TexParameter.PropertyName.TextureMinFilter, (int)GL.GL_LINEAR),
// new TexParameteri(TexParameter.PropertyName.TextureMagFilter, (int)GL.GL_LINEAR));
// texture.Initialize();
// this.hdrTexture = texture;
//}
this.albedoMap = LoadTexture(@"Texture\agedplanks1-albedo.png");
this.albedoMap.TextureUnitIndex = 3;
this.normalMap = LoadTexture(@"Texture\agedplanks1-normal4-ue.png");
this.normalMap.TextureUnitIndex = 4;
this.metallicMap = LoadTexture(@"Texture\agedplanks1-ao.png");
this.metallicMap.TextureUnitIndex = 5;
this.roughnessMap = LoadTexture(@"Texture\agedplanks1-roughness.png");
this.roughnessMap.TextureUnitIndex = 6;
this.aoMap = LoadTexture(@"Texture\agedplanks1-ao.png");
this.aoMap.TextureUnitIndex = 7;
this.pbrProgram.SetUniform("albedoMap", this.albedoMap);
this.pbrProgram.SetUniform("normalMap", this.normalMap);
this.pbrProgram.SetUniform("metallicMap", this.metallicMap);
this.pbrProgram.SetUniform("roughnessMap", this.roughnessMap);
this.pbrProgram.SetUniform("aoMap", this.aoMap);
//设置投影矩阵
mat4 captureProjection = glm.perspective((float)(Math.PI / 2), 1.0f, 0.1f, 20.0f);
mat4[] captureView =
{
glm.lookAt(new vec3(0, 0, 0), new vec3(1.0f, 0.0f, 0.0f), new vec3(0.0f, -1.0f, 0.0f)),
glm.lookAt(new vec3(0, 0, 0), new vec3(-1.0f, 0.0f, 0.0f), new vec3(0.0f, -1.0f, 0.0f)),
glm.lookAt(new vec3(0, 0, 0), new vec3(0.0f, 1.0f, 0.0f), new vec3(0.0f, 0.0f, 1.0f)),
glm.lookAt(new vec3(0, 0, 0), new vec3(0.0f, -1.0f, 0.0f), new vec3(0.0f, 0.0f, -1.0f)),
glm.lookAt(new vec3(0, 0, 0), new vec3(0.0f, 0.0f, 1.0f), new vec3(0.0f, -1.0f, 0.0f)),
glm.lookAt(new vec3(0, 0, 0), new vec3(0.0f, 0.0f, -1.0f), new vec3(0.0f, -1.0f, 0.0f)),
};
ViewportSwitch viewportSwitch = new ViewportSwitch(0, 0, 512, 512);
//转换HDR Equirectangular environmentMap 为 HDR cubeMap
{
//创建渲染到CubeMap的FBO
var fbo = new Framebuffer(512, 512);
fbo.Bind();
var rbo = new Renderbuffer(512, 512, GL.GL_DEPTH_COMPONENT24);
fbo.Attach(FramebufferTarget.Framebuffer, rbo, AttachmentLocation.Depth);
fbo.CheckCompleteness();
fbo.Unbind();
viewportSwitch.On();
ShaderProgram program = this.equiRectangular2CubemapProgram;
program.SetUniform("equirectangularMap", this.hdrTexture);
program.SetUniform("ProjMatrix", captureProjection);
for (uint i = 0; i < 6; ++i)
{
fbo.Bind();
CubemapFace face = (CubemapFace)(GL.GL_TEXTURE_CUBE_MAP_POSITIVE_X + i);
uint location = 0;
int level = 0;
fbo.Attach(FramebufferTarget.Framebuffer, location, face, envCubeMap, level);
fbo.CheckCompleteness();
fbo.Unbind();
fbo.Bind();
program.Bind();
program.SetUniform("ViewMatrix", captureView[i]);
program.PushUniforms();
GL.Instance.Clear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
renderCube();
program.Unbind();
fbo.Unbind();
envCubeMap.GetImage(face, fbo.Width, fbo.Height).Save(
string.Format("envCubeMap.{0}.png", face));
}
viewportSwitch.Off();
fbo.Dispose();
}
//创建一个irradianceMap
{
var fbo = new Framebuffer(irradianceMapLength, irradianceMapLength);
fbo.Bind();
var rbo = new Renderbuffer(irradianceMapLength, irradianceMapLength, GL.GL_DEPTH_COMPONENT24);
fbo.Attach(FramebufferTarget.Framebuffer, rbo, AttachmentLocation.Depth);
fbo.CheckCompleteness();
fbo.Unbind();
//pbr:通过卷积来创建一张irradianceMap来解决diffueIntegral
viewportSwitch.Width = irradianceMapLength; viewportSwitch.Height = irradianceMapLength;
viewportSwitch.On();
ShaderProgram program = this.irradianceProgram;
program.SetUniform("environmentMap", envCubeMap);
program.SetUniform("ProjMatrix", captureProjection);
for (uint i = 0; i < 6; ++i)
{
fbo.Bind();
CubemapFace face = (CubemapFace)(GL.GL_TEXTURE_CUBE_MAP_POSITIVE_X + i);
uint location = 0;
int level = 0;
fbo.Attach(FramebufferTarget.Framebuffer, location, face, irradianceMap, level);
fbo.CheckCompleteness();
fbo.Unbind();
//vec3 color = System.Drawing.Color.SkyBlue.ToVec3();
vec3 color = System.Drawing.Color.Black.ToVec3();
fbo.Bind();
program.Bind();
program.SetUniform("ViewMatrix", captureView[i]);
program.PushUniforms();
GL.Instance.ClearColor(color.x, color.y, color.z, 1);
GL.Instance.Clear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
renderCube();
program.Unbind();
fbo.Unbind();
irradianceMap.GetImage(face, fbo.Width, fbo.Height).Save(
string.Format("irradianceMap.fill.{0}.png", face));
}
viewportSwitch.Off();
fbo.Dispose();
}
//对环境光用蒙特卡洛积分来创建一个prefliterMap贴图
{
ShaderProgram program = this.prefliterProgram;
program.SetUniform("environmentMap", envCubeMap);
program.SetUniform("ProjMatrix", captureProjection);
const int maxMipLevels = 5;
for (int level = 0; level < maxMipLevels; level++)
{
int mipWidth = (int)(128 * Math.Pow(0.5, level));
int mipHeight = (int)(128 * Math.Pow(0.5, level));
var fbo = new Framebuffer(mipWidth, mipHeight);
fbo.Bind();
var rbo = new Renderbuffer(mipWidth, mipHeight, GL.GL_DEPTH_COMPONENT24);
fbo.Attach(FramebufferTarget.Framebuffer, rbo, AttachmentLocation.Depth);
fbo.CheckCompleteness();
fbo.Unbind();
viewportSwitch.Width = mipWidth; viewportSwitch.Height = mipHeight;
viewportSwitch.On();
float roughness = (float)level / (float)(maxMipLevels - 1);
program.SetUniform("roughness", roughness);
for (uint j = 0; j < 6; j++)
{
program.SetUniform("ViewMatrix", captureView[level]);
fbo.Bind();
CubemapFace face = (CubemapFace)(GL.GL_TEXTURE_CUBE_MAP_POSITIVE_X + j);
uint location = 0;
fbo.Attach(FramebufferTarget.Framebuffer, location, face, prefliterMap, level);
fbo.CheckCompleteness();
fbo.Unbind();
fbo.Bind();
program.Bind();
program.PushUniforms();
GL.Instance.Clear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
renderCube();
program.Unbind();
fbo.Unbind();
prefliterMap.GetImage(face, fbo.Width, fbo.Height, level).Save(
string.Format("prefliterMap.{0}.{1}.png", level, face));
}
viewportSwitch.Off();
fbo.Dispose();
}
program.Unbind();
}
{
var fbo = new Framebuffer(512, 512);
fbo.Bind();
var rbo = new Renderbuffer(512, 512, GL.GL_DEPTH_COMPONENT24);
fbo.Attach(FramebufferTarget.Framebuffer, rbo, AttachmentLocation.Depth);
fbo.Attach(FramebufferTarget.Framebuffer, brdfLUTTexture, 0u);
fbo.CheckCompleteness();
fbo.Unbind();
fbo.Bind();
viewportSwitch.Width = 512; viewportSwitch.Height = 512;
viewportSwitch.On();
ShaderProgram program = this.brdfProgram;
program.Bind();
program.PushUniforms();
GL.Instance.Clear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
renderQuad();
program.Unbind();
viewportSwitch.Off();
fbo.Unbind();
fbo.Dispose();
brdfLUTTexture.GetImage(fbo.Width, fbo.Height).Save(
string.Format("BRDF.GetImage.png"));
}
}