为什么OpenSceneGraph将所有Sampler2D映射到第一个纹理

它使用多个纹理进行输入,然后使用预渲染摄影机进行多渲染目标渲染,并使用第二个摄影机读取这些多渲染目标纹理以进行延迟着色。因此,两个相机都有自己的着色器(此处称为geometry\u pass和lighting\u pass)。 sampler2D 阅读时穿制服。

//in geometry_pass.frag
uniform sampler2D uAlbedoMap;
uniform sampler2D uHeightMap;
uniform sampler2D uNormalMap;
uniform sampler2D uRoughnessMap;
uniform sampler2D uSpecularMap;
[...]
layout (location = 0) out vec4 albedo;
layout (location = 1) out vec4 height;
layout (location = 2) out vec4 normal;
layout (location = 3) out vec4 position;
layout (location = 4) out vec4 roughness;
layout (location = 5) out vec4 specular;
[...]
albedo = vec4(texture(uAlbedoMap, vTexCoords).rgb, 1.0);
height = vec4(texture(uHeightMap, vTexCoords).rgb, 1.0);
normal = vec4(texture(uNormalMap, vTexCoords).rgb, 1.0);
position = vec4(vPosition_WorldSpace, 1.0);
roughness = vec4(texture(uRoughnessMap, vTexCoords).rgb, 1.0);
specular = vec4(texture(uSpecularMap, vTexCoords).rgb, 1.0);    

这里的输出始终是 uAlbedoMap

//in lighting_pass.frag
uniform sampler2D uAlbedoMap;
uniform sampler2D uHeightMap;
uniform sampler2D uNormalMap;
uniform sampler2D uPositionMap;
uniform sampler2D uRoughnessMap;
uniform sampler2D uSpecularMap;
[...]
vec3 albedo = texture(uAlbedoMap, vTexCoord).rgb;
vec3 height = texture(uHeightMap, vTexCoord).rgb;
vec3 normal_TangentSpace = texture(uNormalMap, vTexCoord).rgb;
vec3 position_WorldSpace = texture(uPositionMap, vTexCoord).rgb;
vec3 roughness = texture(uRoughnessMap, vTexCoord).rgb;
vec3 specular = texture(uSpecularMap, vTexCoord).rgb;

i、 e.正确导出的位置地图也具有照明过程中反照率的颜色。

因此,似乎正常工作的是纹理输出,但显然不工作的是输入。

现在,一个明显的问题是:如何在着色器中正确使用这些纹理?

项目建设

osgViewer::Viewer ,因此只有一个视图。 这个 displayCamera

osg::ref_ptr<osg::Camera> camera = viewer.getCamera();

osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
traits->windowDecoration = false;
traits->x = 0;
traits->y = 0;
traits->width = 640;
traits->height = 480;
traits->doubleBuffer = true;

camera->setGraphicsContext(new osgQt::GraphicsWindowQt(traits.get()));
camera->getGraphicsContext()->getState()->setUseModelViewAndProjectionUniforms(true);
camera->getGraphicsContext()->getState()->setUseVertexAttributeAliasing(true);
camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
camera->setClearColor(osg::Vec4(0.2f, 0.2f, 0.6f, 1.0f));
camera->setViewport(new osg::Viewport(0, 0, traits->width, traits->height));
camera->setViewMatrix(osg::Matrix::identity());

显示摄像机 对于该查看器相机,创建第二个相机以渲染到纹理(因此称为 rttCamera )并将其作为子对象添加到 显示摄像机 ).

显示摄像机 有两个孩子 矩阵变换->屏幕四元菜单。这个 rttCamera公司 有子场景->晶洞。 显示摄像机 s rendermask,场景 rttCamera公司

使用场景节点,我从文件(所有位图)中读取5个纹理,然后渲染 rttCamera公司

//model is the geode in the scene group node
osg::ref_ptr<osg::StateSet> ss = model->getOrCreateStateSet();
ss->addUniform(new osg::Uniform(name.toStdString().c_str(), counter));
ss->setTextureAttributeAndModes(counter, pairNameTexture.second, osg::StateAttribute::ON | osg::StateAttribute::PROTECTED);

.

//camera is the rttCamera
//bufferComponent is constructed by osg::Camera::COLOR_BUFFER0+counter
//(where counter is just an integer that gets incremented)
//texture is an osg::Texture2D that is newly created
camera->attach(bufferComponent, texture);
//the textures get stored to assign them later on
gBufferTextures[name] = texture;

这些mrt纹理作为纹理绑定到screenquad

//ssQuad is the stateset of the screen quad geode
QString uniformName = "u" + name + "Map";
uniformName[1] = uniformName[1].toUpper();

ssQuad->addUniform(new osg::Uniform(uniformName.toStdString().c_str(), counter));
osg::ref_ptr<osg::Texture2D> tex = gBufferTextures[name];
ssQuad->setTextureAttributeAndModes(counter, gBufferTextures[name], osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);

纹理附件的创建如下(其中使用宽度和高度或大小的二次幂值没有区别)

osg::ref_ptr<osg::Texture2D> Utils::createTextureAttachment(int width, int height)
{
    osg::Texture2D* texture = new osg::Texture2D();
    //texture->setTextureSize(width, height);
    texture->setTextureSize(512, 512);
    texture->setInternalFormat(GL_RGBA);
    texture->setFilter(osg::Texture2D::MIN_FILTER, osg::Texture2D::LINEAR);
    texture->setFilter(osg::Texture2D::MAG_FILTER, osg::Texture2D::LINEAR);

    return texture;
}

如果有更重要的解决代码或信息缺失的方法,请告诉我。