[英]OpenGL ES 2.0 cubemap is not showing a texture
我想实现一个天空盒,但是不知何故没有渲染。 在初始化中,我只是简单地构建加载一个立方体的3个Positioncoords从(-1,-1,-1)到(1,1,1)。 纹理也正在加载,可能会将其添加到立方体贴图。 通过渲染,我只通过了ModelViewProj,但没有平移,缩放或对其应用任何操作,仅是投影。
有人知道为什么它不起作用吗? 我忘记了什么或理解错了吗?
初始化VBO:
_VertexData = skyboxVertices;
_ByteSize = sizeof(GLfloat) * 3;
_NumTriangles = 36;
glEnable(GL_DEPTH_TEST);
glGenVertexArraysOES(1, &_vertexArray);
glBindVertexArrayOES(_vertexArray);
glGenBuffers(1, &vertexBuffer);
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(skyboxVertices), skyboxVertices, GL_STATIC_DRAW);
glEnableVertexAttribArray(GLKVertexAttribPosition);
glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 32, BUFFER_OFFSET(0));
glBindVertexArrayOES(0);
[self loadTextureFromImage:path Type:typ];
加载纹理:
glGenTextures(1, &(_TextureID));
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_CUBE_MAP, _TextureID);
for (int face = 0; face < 6; ++face) {
[self getImage:[NSString stringWithFormat:@"%i",face]];
glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, imageData);
}
glTexParameteri(GL_TEXTURE_CUBE_MAP,GL_TEXTURE_MIN_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_CUBE_MAP,GL_TEXTURE_MAG_FILTER,GL_LINEAR);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
// glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA,(int)width,(int)height,0,GL_RGBA,GL_UNSIGNED_BYTE,imageData);
glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
free(imageData);
绘制Skymap:
glDepthMask(GL_FALSE);
glBindVertexArrayOES(_vertexArray);
glUseProgram(prog);
glEnable(GL_TEXTURE_CUBE_MAP);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_CUBE_MAP, _TextureID);
GLuint projMatrix = glGetUniformLocation(prog, "modelViewProjectionMatrix");
GLuint normalMatrix = glGetUniformLocation(prog, "normalMatrix");
GLuint samplerCube =glGetUniformLocation(prog, "cubeMap");
glUniformMatrix4fv(projMatrix, 1, 0, _modelViewProj.m);
glUniform1i(samplerCube, 0);
glDrawArrays(GL_TRIANGLES, 0, _NumTriangles);
glDepthMask(GL_TRUE);
顶点着色器:
attribute vec4 position;
attribute vec3 texCoord;
attribute vec3 normal;
varying lowp vec3 vTexCoord;
uniform mat4 modelViewMatrix;
uniform mat4 modelViewProjectionMatrix;
uniform mat3 normalMatrix;
void main()
{
vTexCoord = texCoord;
gl_Position = modelViewProjectionMatrix * position;
}
片段着色器:
uniform samplerCube cubeMap;
varying lowp vec3 vTexCoord;
void main()
{
lowp vec4 texCol = textureCube(cubeMap, vTexCoord);
lowp vec4 color = vec4(1.0,0.0,0.0,1.0);
gl_FragColor = vec4(texCol.rgba);
}
这是孔信息
GLfloat skyboxVertices[108] = {
// Positions
-1.0f, 1.0f, -1.0f,
-1.0f, -1.0f, -1.0f,
1.0f, -1.0f, -1.0f,
1.0f, -1.0f, -1.0f,
1.0f, 1.0f, -1.0f,
-1.0f, 1.0f, -1.0f,
-1.0f, -1.0f, 1.0f,
-1.0f, -1.0f, -1.0f,
-1.0f, 1.0f, -1.0f,
-1.0f, 1.0f, -1.0f,
-1.0f, 1.0f, 1.0f,
-1.0f, -1.0f, 1.0f,
1.0f, -1.0f, -1.0f,
1.0f, -1.0f, 1.0f,
1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f,
1.0f, 1.0f, -1.0f,
1.0f, -1.0f, -1.0f,
-1.0f, -1.0f, 1.0f,
-1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f,
1.0f, -1.0f, 1.0f,
-1.0f, -1.0f, 1.0f,
-1.0f, 1.0f, -1.0f,
1.0f, 1.0f, -1.0f,
1.0f, 1.0f, 1.0f,
1.0f, 1.0f, 1.0f,
-1.0f, 1.0f, 1.0f,
-1.0f, 1.0f, -1.0f,
-1.0f, -1.0f, -1.0f,
-1.0f, -1.0f, 1.0f,
1.0f, -1.0f, -1.0f,
1.0f, -1.0f, -1.0f,
-1.0f, -1.0f, 1.0f,
1.0f, -1.0f, 1.0f
};
您的多维数据集生成代码有错误:
for (int face = 1; face <= 6; ++face) {
您应该将其运行在0到5之间,否则您将不会上传GL_TEXTURE_CUBE_MAP_POSITIVE_X的任何内容,而会上传GL_TEXTURE_CUBE_MAP_POSITIVE_X + 6的内容,这是无效的。
您应该显示着色器,因为那里也可能有错误。
编辑
缓冲区创建似乎不正确。 当您拥有一个位置,texCoord和一个普通属性时,您应该具有3个顶点attrib指针,每个对应一个:
glEnableVertexAttribArray(0); //position
glEnableVertexAttribArray(1); //texcoord
glEnableVertexAttribArray(2); //normal
glVertexAttribPointer(0, 4, GL_FLOAT, false, vertexByteSize, 0); //position
glVertexAttribPointer(1, 3, GL_FLOAT, false, vertexByteSize, (void*)(4 * 4)); //texCoord
glVertexAttribPointer(2, 3, GL_FLOAT, false, vertexByteSize, (void*)(7 * 4)); //normal
注意我将0 1 2用于属性位置,在实现中应使用glGetAttribLocation()获取它们;
另外,您的变量_NumTriangles应该命名为_NumVertices,因为它拥有顶点数量(一个立方体有12个三角形-> 12 * 3 =上传了36个顶点)。
此外,包含数据的缓冲区可能存在一些错误,您也可以复制吗?
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