我已经阅读了一段时间用于纹理地形的不同技术并遇到了
texture splatting.我发现很多文章讨论如何在OpenGL中做到这一点,但大多数只在理论上讨论它并提供很少甚至没有代码我可以研究.有谁知道/有一些代码在OpenGL中说明了这一点？

为了澄清,我希望能够加载四种不同的纹理,并根据四边形/顶点的高度,将纹理从一个渐变到下一个.

编辑：下面是一些代码,以帮助显示我想知道的内容

#include <windows.h>
#include <SFML/Graphics.hpp>
#include <gl/gl.h>
#include <gl/glu.h>

#define GL_CLAMP_TO_EDGE 0x812F

class Scene {
public:
    void resize( int w, int h ) {
        // OpenGL Reshape
        glViewport( 0, 0, w, h );
        glMatrixMode( GL_PROJECTION );
        glLoadIdentity();
        gluPerspective( 120.0, (GLdouble)w/(GLdouble)h, 0.5, 500.0 );
        glMatrixMode( GL_MODELVIEW );
    }
};

int main() {

    sf::RenderWindow window(sf::VideoMode(800, 600, 32), "Test");

    ///Setup the scene, materials, lighting
    Scene scene;
    scene.resize(800,600);
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_LIGHTING);
    glColorMaterial(GL_FRONT_AND_BACK, GL_EMISSION);
    glEnable(GL_COLOR_MATERIAL);
    glShadeModel(GL_SMOOTH);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glEnable(GL_LIGHT0);
    float XL = .5, YL = .1, ZL = 1;
    GLfloat ambientLight[] = { 0.2f, 0.2f, 0.2f, 1.0f };
    GLfloat diffuseLight[] = { 0.8f, 0.8f, 0.8, 1.0f };
    GLfloat specularLight[] = { 0.5f, 0.5f, 0.5f, 1.0f };
    GLfloat lightpos[] = {XL, YL, ZL, 0.};
    glLightfv(GL_LIGHT0, GL_AMBIENT, ambientLight);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuseLight);
    glLightfv(GL_LIGHT0, GL_SPECULAR, specularLight);
    glLightfv(GL_LIGHT0, GL_POSITION, lightpos);

    ///Test terrain texture splatting

    ///Load the textures
    sf::Image tex1;
    tex1.loadFromFile("texture1.png");
    sf::Image tex2;
    tex2.loadFromFile("texture2.png");

    ///Set the first texture
    GLuint grass;
    glGenTextures(1, &grass);
    glBindTexture(GL_TEXTURE_2D, grass);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, tex1.getSize().x, tex1.getSize().y, 0, GL_RGBA, GL_UNSIGNED_BYTE, (const GLvoid*)tex1.getPixelsPtr() );

    ///Set the second texture
    GLuint dirt;
    glGenTextures(1, &dirt);
    glBindTexture(GL_TEXTURE_2D, dirt);
    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
    glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
    glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, tex2.getSize().x, tex2.getSize().y, 0, GL_RGBA, GL_UNSIGNED_BYTE, (const GLvoid*)tex2.getPixelsPtr() );

    ///Start loop
    while( window.isOpen() ) {
        sf::Event event;
        while( window.pollEvent( event ) ) {
            if( event.type == sf::Event::Closed )
                window.close();
        }

        ///Clear buffer and set camera
        glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        gluPerspective(50.0, 1.0, 1.0, 50);
        glMatrixMode(GL_MODELVIEW);
        glLoadIdentity();
        gluLookAt(1, 0, 1, 0, 0, 0, 0, 1, 0);

        ///Begin rendering quad             
        glEnable(GL_TEXTURE_2D);
        glBindTexture(GL_TEXTURE_2D, grass);
        ///I know that around here I should enable blending in order to get my two textures to mix, but I am not certain
        glBegin(GL_QUADS);

            glTexCoord2f(0, 0);
            glVertex3f(-0.5, -0.5, 0.0);

            glTexCoord2f(1, 0);
            glVertex3f(-0.5, 0.5, 0.0);

            glTexCoord2f(1, 1);
            glVertex3f(0.5, 0.5, 0.0);

            glTexCoord2f(0, 1);
            glVertex3f(0.5, -0.5, 0.0);
        glEnd();

        ///Reset env settings for SFML
        glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);

        window.display();
    }
    return 1;
}

最佳答案 如上所述,使用可编程管道,使用着色器.在片段着色器中,您可以传递所有纹理,并根据从顶点着色器接收的顶点数据在它们之间进行插值.

快速搜索给了我this result.我相信这就是你所需要的.另请参阅this post. this论文非常好地解释了这项技术.