[英]OpenGL texture not displayed (solid color instead texture) or displayed with artifacts
[英]OpenGL solid color displayed instead of texture
因此,我查看了本網站和其他網站中的所有類似問題,但未能找到答案為什么我的紋理無法加載。 我確定紋理可以正確讀取,但是,只是沒有正確應用它。 這是我的代碼:
獲取紋理:
glGenTextures(NumTextures, textures);
glActiveTexture( GL_TEXTURE0 );
// load and bind tree texture
readPPM6("textures/tree_trunk.pbm", treeTex);
glBindTexture(GL_TEXTURE_2D, textures[0]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 0);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, 128, 128, 0, GL_RGB,
GL_UNSIGNED_BYTE, treeTex);
綁定對象:
// VAO[Tree]
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vElements[TreeE]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLushort)*treeIndices.size(), treeIndices.data(), GL_STATIC_DRAW);
glBindVertexArray(vArrays[TreeA]);
glBindBuffer(GL_ARRAY_BUFFER, vBuffers[TreeB]);
glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat)*treeVertices.size() + sizeof(vec2) * 90, NULL, GL_STATIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(GLfloat)*treeVertices.size(), treeVertices.data());
glBufferSubData(GL_ARRAY_BUFFER, sizeof(GLfloat)*treeVertices.size(), sizeof(vec2)*90,
treeTexCoords);
glUseProgram( texture );
vPosition = glGetAttribLocation( texture, "vPosition" );
glVertexAttribPointer( vPosition, 4, GL_FLOAT, GL_FALSE, 0, 0);
glEnableVertexAttribArray(vPosition);
vTexCoord = glGetAttribLocation( texture, "vTexCoord" );
glVertexAttribPointer( vTexCoord, 2, GL_FLOAT, GL_FALSE, 0,
(const void*) ((sizeof(GLfloat) * treeVertices.size())));
glEnableVertexAttribArray( vTexCoord );
glUniform1i(glGetUniformLocation(texture, "texture"), 0);
glBindVertexArray(0);
繪制樹:
glUseProgram(texture);
proj_loc = glGetUniformLocation(texture, "projection");
model_view_loc = glGetUniformLocation(texture, "modelview");
glUniformMatrix4fv(proj_loc, 1, GL_TRUE, projmat);
glUniformMatrix4fv(model_view_loc, 1, GL_TRUE, modelmat);
glEnable(GL_PRIMITIVE_RESTART);
glPrimitiveRestartIndex(0xFFFF);
glBindVertexArray(vArrays[TreeA]);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vElements[TreeE]);
glEnable(GL_TEXTURE_2D);
glActiveTexture( GL_TEXTURE0 );
glBindTexture(GL_TEXTURE_2D, textures[0]);
glDrawElements(GL_TRIANGLE_STRIP, treeIndices.size(), GL_UNSIGNED_SHORT, NULL);
glDisable(GL_PRIMITIVE_RESTART);
glDisable(GL_TEXTURE_2D);
glUseProgram(0);
glBindVertexArray(0);
樹的創建方式:
getCylinderVertices(treeVertices, 10.0, 3.0, 10);
getCylinderIndices(treeIndices, 10);
getConeVertices(treeVertices, 10.0, 15.0, 6.0, 10);
for (int i = 0; i < 10; i++)
{
treeIndices.push_back(60+i*3);
treeIndices.push_back(60+i*3+1);
treeIndices.push_back(60+i*3+2);
treeIndices.push_back(0xFFFF);
}
treeTexCoords = new vec2[90];
for (int i = 0; i < 10; i++)
{
treeTexCoords[i*6] = vec2(0.0, 0.0);
treeTexCoords[i*6+1] = vec2(0.0, 0.2);
treeTexCoords[i*6+2] = vec2(0.0, 0.0);
treeTexCoords[i*6+3] = vec2(1.0, 0.2);
treeTexCoords[i*6+4] = vec2(1.0, 0.0);
treeTexCoords[i*6+5] = vec2(0.0, 0.0);
}
for (int i = 0; i < 30; i++)
{
treeTexCoords[60+i] = vec2(0.0,0.0);
}
頂點着色器:
#version 330 core
attribute vec4 vPosition;
uniform mat4 projection;
uniform mat4 modelview;
attribute vec4 vertex;
attribute vec3 normal;
attribute vec2 vTexCoord;
out vec2 texCoord;
void main()
{
texCoord = vTexCoord;
gl_Position = projection*modelview*vPosition;
}
片段着色器:
#version 330 core
in vec2 texCoord;
uniform sampler2D texture;
void main()
{
gl_FragColor = texture2D(texture, texCoord);
}
解決緩沖區子數據分配問題后,這是當前樹的外觀: http : //i.imgur.com/dMBq9xN.jpg
供參考,這是我正在使用的圖像: http : //i.imgur.com/QuuQQ5i.jpg
我已經解決了最后一個問題,讀者正在閱讀作為圖像一部分的終點線,因此一切都轉移到了下一種顏色。 謝謝大家的幫助。
我很驚訝這段代碼不會導致崩潰, sizeof (vec2) * 90
是您在第二次調用glBufferSubData (...)
應該使用的值,因為紋理坐標數組中的浮點分量的數量是頂點位置數組中的組件數。 當您用數據填充緩沖區時,您將同時超過VBO的存儲空間和客戶端內存中的紋理坐標數組。
sizeof (treeTexCoords)
絕對不是您想要的,因為您已經動態分配了該數組! 如果嘗試使用指向分配有new
內存的指針來執行大小調整操作,則可以使用sizeof (...)
來獲取靜態大小的數組的大小,但您得到的只是指針本身的大小。 因此,您的系統上的sizeof (treeTexCoords)
可能是4或8 。
glBindVertexArray (vArrays [TreeA]);
glBindBuffer (GL_ARRAY_BUFFER, vBuffers [TreeB]);
//
// @CORRECTION #1
//
glBufferData (GL_ARRAY_BUFFER, sizeof (GLfloat) * treeVertices.size () +
sizeof (vec2) * 90,
NULL, GL_STATIC_DRAW);
glBufferSubData (GL_ARRAY_BUFFER, 0,
sizeof (GLfloat) * treeVertices.size (),
treeVertices.data ());
//
// @CORRECTION #2
//
glBufferSubData (GL_ARRAY_BUFFER, sizeof (GLfloat) * treeVertices.size (),
sizeof (vec2) * 90,
treeTexCoords);
修正#1分配了適當的存儲量(而不是所有頂點+ 1指針的足夠存儲量)。
更正#2只能讀取到treeTexCoords
的末尾,而不是treeTexCoords
它。
根據treeVertices
的聲明方式,可能還會有其他問題-您可以編輯問題以顯示treeVertices
的聲明嗎? 我假設它像std::vector <GLfloat>
。
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