[英]OpenGL Texture White Line Gaps
作为副项目,我已经有一段时间了,我一直在尝试创建一些Voxel地形。 但是,令我沮丧的是纹理似乎无法正常工作。 我正在使用GL_REPEAT和GL_NEAREST映射纹理。 纹理可以在精灵表中找到,并且为16x16。 我目前正在使用Minecraft纹理进行调试。 我试图通过移动纹理1 texel来修复它,但这也不起作用。
这是处理它的代码:
void Chunk::CreateCube(int x, int y, int z, bool activeStates[], int ID)
{
double TEXTURE_SIZE = 256;
glm::vec3 p1(x-BLOCK_RENDER_SIZE, y-BLOCK_RENDER_SIZE, z+BLOCK_RENDER_SIZE); //left bottom front
glm::vec2 t1(0.5/TEXTURE_SIZE, 0.5/TEXTURE_SIZE);
glm::vec3 p2(x+BLOCK_RENDER_SIZE, y-BLOCK_RENDER_SIZE, z+BLOCK_RENDER_SIZE); //right bottom front
glm::vec2 t2(1-(0.5/TEXTURE_SIZE), 0.5/TEXTURE_SIZE);
glm::vec3 p3(x+BLOCK_RENDER_SIZE, y+BLOCK_RENDER_SIZE, z+BLOCK_RENDER_SIZE); // right top front
glm::vec2 t3(1-(0.5/TEXTURE_SIZE), 1-(0.5/TEXTURE_SIZE));
glm::vec3 p4(x-BLOCK_RENDER_SIZE, y+BLOCK_RENDER_SIZE, z+BLOCK_RENDER_SIZE); // left top front
glm::vec2 t4(0.5/TEXTURE_SIZE, 1-(0.5/TEXTURE_SIZE));
glm::vec3 p5(x+BLOCK_RENDER_SIZE, y-BLOCK_RENDER_SIZE, z-BLOCK_RENDER_SIZE); // right bottom back
glm::vec2 t5(0.5/TEXTURE_SIZE, 0.5/TEXTURE_SIZE);
glm::vec3 p6(x-BLOCK_RENDER_SIZE, y-BLOCK_RENDER_SIZE, z-BLOCK_RENDER_SIZE); // left bottom back
glm::vec2 t6(1-(0.5/TEXTURE_SIZE), 0.5/TEXTURE_SIZE);
glm::vec3 p7(x-BLOCK_RENDER_SIZE, y+BLOCK_RENDER_SIZE, z-BLOCK_RENDER_SIZE); // left top back
glm::vec2 t7(1-(0.5/TEXTURE_SIZE), 1-(0.5/TEXTURE_SIZE));
glm::vec3 p8(x+BLOCK_RENDER_SIZE, y+BLOCK_RENDER_SIZE, z-BLOCK_RENDER_SIZE); // right top back
glm::vec2 t8(0.5/TEXTURE_SIZE, 1-(0.5/TEXTURE_SIZE));
int numCols = 16;
int numRows = 16;
double u = ((double)(ID % numCols) / (double)numCols);
double v = ((double)(ID / numRows) / (double)numRows);
double TILE_TEXTURE_SIZE = 16;
glm::vec3 n1;
if(activeStates[5] == false)
{
// Front Face Normal
n1 = glm::vec3(0.0f, 0.0f, 1.0f);
//Triangle 1
vertexData.push_back(p1);
uvData.push_back(glm::vec2(t1.x/TILE_TEXTURE_SIZE + u, t1.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p2);
uvData.push_back(glm::vec2(t2.x/TILE_TEXTURE_SIZE + u, t2.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p3);
uvData.push_back(glm::vec2(t3.x/TILE_TEXTURE_SIZE + u, t3.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
//Triangle 2
vertexData.push_back(p1);
uvData.push_back(glm::vec2(t1.x/TILE_TEXTURE_SIZE + u, t1.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p3);
uvData.push_back(glm::vec2(t3.x/TILE_TEXTURE_SIZE + u, t3.y/TILE_TEXTURE_SIZE + v ));
normalData.push_back(n1);
vertexData.push_back(p4);
uvData.push_back(glm::vec2(t4.x/TILE_TEXTURE_SIZE + u, t4.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
}
if(activeStates[4] == false)
{
// Back
n1 = glm::vec3(0.0f, 0.0f, -1.0f);
//Triangle 1
vertexData.push_back(p5);
uvData.push_back(glm::vec2(t5.x/TILE_TEXTURE_SIZE + u, t5.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p6);
uvData.push_back(glm::vec2(t6.x/TILE_TEXTURE_SIZE + u, t6.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p7);
uvData.push_back(glm::vec2(t7.x/TILE_TEXTURE_SIZE + u, t7.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
//Triangle 2
vertexData.push_back(p5);
uvData.push_back(glm::vec2(t5.x/TILE_TEXTURE_SIZE + u, t5.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p7);
uvData.push_back(glm::vec2(t7.x/TILE_TEXTURE_SIZE + u, t7.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p8);
uvData.push_back(glm::vec2(t8.x/TILE_TEXTURE_SIZE + u, t8.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
}
if(activeStates[1] == false)
{
// Right
n1 = glm::vec3(1.0f, 0.0f, 0.0f);
//Triangle 1
vertexData.push_back(p2);
uvData.push_back(glm::vec2(t2.x/TILE_TEXTURE_SIZE + u, t2.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p5);
uvData.push_back(glm::vec2(t5.x/TILE_TEXTURE_SIZE + u, t5.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p8);
uvData.push_back(glm::vec2(t8.x/TILE_TEXTURE_SIZE + u, t8.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
//Triangle 2
vertexData.push_back(p2);
uvData.push_back(glm::vec2(t2.x/TILE_TEXTURE_SIZE + u, t2.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p8);
uvData.push_back(glm::vec2(t8.x/TILE_TEXTURE_SIZE + u, t8.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p3);
uvData.push_back(glm::vec2(t3.x/TILE_TEXTURE_SIZE + u, t3.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
}
if(activeStates[0] == false)
{
// left
n1 = glm::vec3(-1.0f, 0.0f, 0.0f);
//Triangle 1
vertexData.push_back(p6);
uvData.push_back(glm::vec2(t6.x/TILE_TEXTURE_SIZE + u, t6.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p1);
uvData.push_back(glm::vec2(t1.x/TILE_TEXTURE_SIZE + u, t1.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p4);
uvData.push_back(glm::vec2(t4.x/TILE_TEXTURE_SIZE + u, t4.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
//Triangle 2
vertexData.push_back(p6);
uvData.push_back(glm::vec2(t6.x/TILE_TEXTURE_SIZE + u, t6.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p4);
uvData.push_back(glm::vec2(t4.x/TILE_TEXTURE_SIZE + u, t4.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p7);
uvData.push_back(glm::vec2(t7.x/TILE_TEXTURE_SIZE + u, t7.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
}
if(activeStates[3] == false)
{
// Top
n1 = glm::vec3(0.0f, 1.0f, 0.0f);
//Triangle 1
vertexData.push_back(p4);
uvData.push_back(glm::vec2(t6.x/TILE_TEXTURE_SIZE + u, t6.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p3);
uvData.push_back(glm::vec2(t1.x/TILE_TEXTURE_SIZE + u, t1.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p8);
uvData.push_back(glm::vec2(t4.x/TILE_TEXTURE_SIZE + u, t4.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
//Triangle 2
vertexData.push_back(p4);
uvData.push_back(glm::vec2(t6.x/TILE_TEXTURE_SIZE + u, t6.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p8);
uvData.push_back(glm::vec2(t4.x/TILE_TEXTURE_SIZE + u, t4.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p7);
uvData.push_back(glm::vec2(t7.x/TILE_TEXTURE_SIZE + u, t7.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
}
if(activeStates[2] == false)
{
// Bottom
n1 = glm::vec3(0.0f, -1.0f, 0.0f);
//Triangle 1
vertexData.push_back(p6);
uvData.push_back(glm::vec2(t6.x/TILE_TEXTURE_SIZE + u, t6.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p5);
uvData.push_back(glm::vec2(t1.x/TILE_TEXTURE_SIZE + u, t1.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p2);
uvData.push_back(glm::vec2(t4.x/TILE_TEXTURE_SIZE + u, t4.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
//Triangle 2
vertexData.push_back(p6);
uvData.push_back(glm::vec2(t6.x/TILE_TEXTURE_SIZE + u, t6.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p2);
uvData.push_back(glm::vec2(t4.x/TILE_TEXTURE_SIZE + u, t4.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
vertexData.push_back(p1);
uvData.push_back(glm::vec2(t7.x/TILE_TEXTURE_SIZE + u, t7.y/TILE_TEXTURE_SIZE + v));
normalData.push_back(n1);
}
/*glm::vec2 t1(0.5/256, 0.5/256);
glm::vec2 t2(1-(0.5/256), 0.5/256);
glm::vec2 t3(1-(0.5/256), 1-(0.5/256));
glm::vec2 t4(0.5/256, 1-(0.5/256));
glm::vec2 t5(0.5/256, 0.5/256);
glm::vec2 t6(1-(0.5/256), 0.5/256);
glm::vec2 t7(1-(0.5/256), 1-(0.5/256));
glm::vec2 t8(0.5/256, 1-(0.5/256));
*/
/*
for(int i = 0; i < vertexData.size(); i+=3)
{
// get the three vertices that make the faces
glm::vec3 p1 = vertexData[i+0];
glm::vec3 p2 = vertexData[i+1];
glm::vec3 p3 = vertexData[i+2];
glm::vec3 v1 = p2 - p1;
glm::vec3 v2 = p3 - p1;
glm::vec3 normal = glm::cross( v1,v2 );
normal = glm::normalize(normal);
normalData[i+0] = normal;
normalData[i+1] = normal;
normalData[i+2] = normal;
}
*/
}
GLuint Graphics3D::loadTexture(const char* theFileName)
{
ILuint imageID;
GLuint textureID;
ILboolean success;
ILenum error;
ilGenImages(1, &imageID);
ilBindImage(imageID);
success = ilLoadImage(theFileName);
if (success)
{
ILinfo ImageInfo;
iluGetImageInfo(&ImageInfo);
if (ImageInfo.Origin == IL_ORIGIN_UPPER_LEFT)
{
// iluFlipImage();
}
success = ilConvertImage(IL_RGB, IL_UNSIGNED_BYTE);
if (!success)
{
error = ilGetError();
std::cout << "Image conversion failed - IL reports error: " << error << " - " << iluErrorString(error) << std::endl;
}
glGenTextures(1, &textureID);
glBindTexture(GL_TEXTURE_2D, textureID);
glTexImage2D(GL_TEXTURE_2D, // Type of texture
0, // Pyramid level (for mip-mapping) - 0 is the top level
ilGetInteger(IL_IMAGE_BPP), // Image colour depth
ilGetInteger(IL_IMAGE_WIDTH), // Image width
ilGetInteger(IL_IMAGE_HEIGHT), // Image height
0, // Border width in pixels (can either be 1 or 0)
ilGetInteger(IL_IMAGE_FORMAT), // Image format (i.e. RGB, RGBA, BGR etc.)
GL_UNSIGNED_BYTE, // Image data type
ilGetData()); // The actual image data itself
/*
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
*/
// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
if(GLEW_EXT_texture_filter_anisotropic)
{
GLfloat maximumAnisotropy;
//get the value
glGetFloatv(GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT, &maximumAnisotropy);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAX_ANISOTROPY_EXT, maximumAnisotropy);
}
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST_MIPMAP_LINEAR);
// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glGenerateMipmap(GL_TEXTURE_2D);
}
else
{
error = ilGetError();
std::cout << "Image load failed - IL reports error: " << error << " - " << iluErrorString(error) << std::endl;
}
ilDeleteImages(1, &imageID);
std::cout << "Texture creation successful." << std::endl;
return textureID;
}
看来我越远,线条越明显。 因此,我尝试删除mipmap。 这也没有帮助。 我不知道如何处理这个问题。 有任何想法吗? 这是纹理:
几乎可以肯定,这归因于启用了某种形式的过滤。
我注意到您正在打开各向异性过滤。 即使没有mip映射,这也会导致获取子纹理外部的像素,从而导致像您在此处看到的伪像。
您确实需要关闭它,并摆脱Mip映射。
另外,我认为您的UV生成已关闭,并且包含一些错误。 这些可能不是这里的问题,但我建议您修复它们。
例如,在此处添加一半纹理像素:
glm::vec2 t1(0.5/TEXTURE_SIZE, 0.5/TEXTURE_SIZE);
但是,此后会按比例缩小,因此实际上您只需要少量补偿即可。 无论如何,这可能都是不必要的(为什么您认为根本需要这样做?),但是几乎可以肯定,它并没有按照您的想法去做。 很小的偏移量可能是个不错的主意,可以防止舍入误差将获取的纹理像素滑入下一个子纹理,但数量很小。
然后您执行以下操作:
double u = ((double)(ID % numCols) / (double)numCols);
double v = ((double)(ID / numRows) / (double)numRows);
您应该使用相同的值来除以ID
和取模。 这仅适用于您具有相同数量的行和列。
最后,您可以这样计算UV:
t1.x/TILE_TEXTURE_SIZE + u
用图块大小划分是错误的。 它应该是* TILE_SIZE / TEXTURE_SIZE
。 幸运的是,这恰好是相同的(256/16 = 16)。 如果您使用不同大小的纹理,则将无法使用。
您的基本问题是将多个图像平铺为一个大纹理。 这将导致任何形式的纹理过滤(例如mipmapping和各向异性过滤)出现问题。 您不想禁用纹理过滤。 相反,应该在逻辑上将每个图像都视为一个不同的图像。 一种简单的方法是使每个图块具有单独的纹理。 这有点慢,所以为了获得更好的性能,您应该改用Array Texture 。
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