一直在阅读“OpenGL 4.0 Shading Language Cookbook”。但是我在立方体贴图教程中遇到了麻烦。
问题是我正在绘制的模型看起来完全是灰色的。好像它没有从 samplerCube 纹理中获取任何数据。
我所有的代码似乎都是正确的。我看过其他教程，也是一样的。不知道我的 Intel HD Graphics 4000 是否负责，但我确定我确实有 GL_ARB_texture_cube_map 扩展。
我正在使用 DevIL 库从文件中加载图像，这似乎做得很好，但据我所知，在将数据传输到 OpenGL 时出现了问题。
我正在发布从文件中获取数据的加载。所有文件也都正确加载。我还发布了绘图代码，我将纹理绑定到管道。而且我还发布了我的顶点和片段着色器以防万一，但它们似乎确实在正常工作。
有任何想法吗？
加载代码
uint TARGETS[6] =
{
GL_TEXTURE_CUBE_MAP_POSITIVE_X,
GL_TEXTURE_CUBE_MAP_NEGATIVE_Y,
GL_TEXTURE_CUBE_MAP_POSITIVE_Y,
GL_TEXTURE_CUBE_MAP_NEGATIVE_Y,
GL_TEXTURE_CUBE_MAP_POSITIVE_Z,
GL_TEXTURE_CUBE_MAP_NEGATIVE_Z
};
string EXTS[6] =
{
"posx",
"negx",
"posy",
"negy",
"posz",
"negz"
};
// Create & bind cubemap texture
glGenTextures( 1, &cubemap );
glBindTexture( GL_TEXTURE_CUBE_MAP, cubemap );
for( int i = 0; i < 6; i++ )
{
string file = "textures/cubemap_" + EXTS[i] + ".png";
uint image = ilGenImage();
// Load with DevIL
ilBindImage( image );
if( !ilLoadImage( file.c_str() ) )
{
cout << "ERROR: Failed to load image " << endl;
return false;
}
// Fetch info from DevIL
int width = ilGetInteger( IL_IMAGE_WIDTH );
int height = ilGetInteger( IL_IMAGE_HEIGHT );
uint format = ilGetInteger( IL_IMAGE_FORMAT );
uint type = ilGetInteger( IL_IMAGE_TYPE );
// Send data to OpenGL
glTexImage2D(
TARGETS[i],
0,
GL_RGBA,
width,
height,
0,
format,
type,
ilGetData() );
// Error check
if( !ErrorCheck("Failed to bind a side of the cubemap!") )
return false;
// Get rid of DevIL data
ilDeleteImage( image );
}
// Parameters
glTexParameterf( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
glTexParameterf( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
glTexParameterf( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
glTexParameterf( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
glTexParameterf( GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE );
绘制代码
// Update
glfwPollEvents();
UpdateTime();
// Clear back buffer for new frame
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
// Bind shader
shader->Bind();
// Cubemap
shader->SetUniform( "cubemapTexture", 0 );
glActiveTexture( GL_TEXTURE0 );
glBindTexture( GL_TEXTURE_CUBE_MAP, cubemap );
// Bind model
if( model->Bind() )
{
static float angle = 0;
angle += 25.0f * deltaTime;
// Matrices
mat4 world =
translate( vec3( 0.0f, 0.0f, 0.0f) ) *
rotateZ( angle * PI / 180 ) *
rotateX( angle * PI / 180 ) *
scale( vec3( 1.0f, 1.0f, 1.0f) );
mat4 view = ViewMatrix(
cameraPosition,
cameraTarget,
vec3( 0.0f, 0.0f, 1.0f) );
mat4 proj = ProjectionMatrix(
fov,
(float)windowX,
(float)windowY,
nearPlane,
farPlane );
// Uniforms
shader->SetUniform( "uWorld", world );
shader->SetUniform( "uView", view );
shader->SetUniform( "uProj", proj );
shader->SetUniform( "materialColor", vec3( 0.5f, 0.5f, 0.5f ) );
shader->SetUniform( "drawSkybox", false );
shader->SetUniform( "world_cameraPosition", cameraPosition );
shader->SetUniform( "reflectFactor", 0.5f );
// Draw
glDrawElements( GL_TRIANGLES, model->GetIndexCount(), GL_UNSIGNED_SHORT, NULL );
}
// Put the new image on the screen
glfwSwapBuffers( window );
顶点着色器
#version 400
layout(location=0) in vec3 vertex_position;
layout(location=1) in vec3 vertex_normal;
layout(location=2) in vec4 vertex_tangent;
layout(location=3) in vec2 vertex_texCoords;
out vec2 texCoords;
out vec3 reflectDir;
uniform mat4 uWorld;
uniform mat4 uView;
uniform mat4 uProj;
uniform bool drawSkybox;
uniform vec3 world_cameraPosition;
void main()
{
if( drawSkybox )
{
reflectDir = vertex_position;
}
else
{
vec3 world_pos = vec3( uWorld * vec4(vertex_position,1.0) );
vec3 world_norm = vec3( uWorld * vec4(vertex_normal,0.0) );
vec3 world_view = normalize( world_cameraPosition - world_pos );
reflectDir = reflect( -world_view, world_norm );
}
gl_Position = uProj * uView * uWorld * vec4(vertex_position,1.0);
texCoords = vertex_texCoords;
}
片段着色器
#version 400
out vec4 fragColor;
in vec2 texCoords;
in vec3 reflectDir;
uniform samplerCube cubemapTexture;
uniform vec3 materialColor;
uniform bool drawSkybox;
uniform float reflectFactor;
void main()
{
vec3 color = texture( cubemapTexture, reflectDir ).rgb;
if( drawSkybox )
{
fragColor = vec4( color, 1.0 );
}
else
{
fragColor = vec4( mix( materialColor, color, reflectFactor ), 1.0 );
}
}