表面细分的理论和算法 [英] Theories and algorithms for subdivision of surfaces
本文介绍了表面细分的理论和算法的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有以下问题：
这是我如何在屏幕上绘制一个多维数据集：
void drawCube（）
{
// glClear（GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT）; //清除颜色和深度缓冲区
glPushAttrib（GL_POLYGON_BIT | GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT）;
glPolygonMode（GL_FRONT_AND_BACK，GL_LINE）;
/ / glDisable（GL_LIGHTING）;
glBegin（GL_QUADS）; //开始绘制尺寸为3cm x 3.5cm x 4cm的颜色立方体
//顶面（y = 1.0f）
//以逆时针（CCW）顺序定义顶点，正常指向
glColor3f（0.0f，1.0f，0.0f）; // Green
glVertex3f（1.75f，1.75f，-4.0f）;
glVertex3f（-1.75f，1.75f，-4.0f）;
glVertex3f（-1.75f，1.75f，1.0f）;
glVertex3f（1.75f，1.75f，1.0f）;
//底面（y = -1.0f）
glColor3f（1.0f，0.5f，0.0f）; // Orange
glVertex3f（1.75f，-1.75f，1.0f）;
glVertex3f（-1.75f，-1.75f，1.0f）;
glVertex3f（-1.75f，-1.75f，-4.0f）;
glVertex3f（1.75f，-.75f，-4.0f）;
//前面（z = 1.0f）
glColor3f（1.0f，0.0f，0.0f）; // Red
glVertex3f（1.75f，1.75f，1.0f）;
glVertex3f（-1.75f，1.75f，1.0f）;
glVertex3f（-1.75f，-1.75f，1.0f）;
glVertex3f（1.75f，-1.75f，1.0f）;
//背面（z = -1.0f）
glColor3f（1.0f，1.0f，0.0f）; //黄
glVertex3f（1.75f，-1.75f，-4.0f）;
glVertex3f（-1.75f，-1.75f，-4.0f）;
glVertex3f（-1.75f，1.75f，-4.0f）;
glVertex3f（1.75f，1.75f，-4.0f）;
//左脸（x = -1.0f）
glColor3f（0.0f，0.0f，1.0f）; // Blue
glVertex3f（-1.75f，1.75f，1.0f）;
glVertex3f（-1.75f，1.75f，-4.0f）;
glVertex3f（-1.75f，-1.75f，-4.0f）;
glVertex3f（-1.75f，-1.75f，1.0f）;
//右脸（x = 1.0f）
glColor3f（1.0f，0.0f，1.0f）; // magenta
glVertex3f（1.75f，1.75f，-4.0f）;
glVertex3f（1.75f，1.75f，1.0f）;
glVertex3f（1.75f，-1.75f，1.0f）;
glVertex3f（1.75f，-1.75f，-4.0f）;
glEnd（）; // end of drawing color-cube
glPopAttrib（）;问题是如何在所有顶点之间分配样本点？问题是如何在所有顶点之间分配样本点？
从我的理解，我需要找到顶点之间的距离，并将其分成（说）五个相等的部分。为了论证起见，假设两个顶点之间的空间是1，因此5个点将被放置在彼此的0.2距离上。它们还需要以一种存储器结构（向量/数组）的形式存储，以便在稍后阶段可以访问它们中的每一个并将其转换为屏幕坐标。
但是，我怎么能在C ++中以完全通用的方式做到这一点，以便它可以应用于任何距离度量？
这是使用创建的数组的示例，用于收集某些形状统计信息
//示例
//查找形状坐标的最小最大值
//获取第一个顶点的坐标
float fMinX = pfVertices [0];
float fMinY = pfVertices [1];
float fMinZ = pfVertices [2];
float fMaxX = pfVertices [0];
float fMaxY = pfVertices [1];
float fMaxZ = pfVertices [2]
for（int iVertexIndex = 0; iVertexIndex<（iTopButtonQuads + iLeftRightQuads + iFrontBackQuads）* 4; iVertexIndex ++）
{
int iCurrentIndex = iVertexIndex * 3; //（x y z）per vertex
if（pfVertices [iCurrentIndex]< fMinX）
fMinX = pfVertices [iCurrentIndex];
if（pfVertices [iCurrentIndex + 1]< fMinY）
fMinY = pfVertices [iCurrentIndex + 1];
if（pfVertices [iCurrentIndex + 2]< fMinZ）
fMinZ = pfVertices [iCurrentIndex + 2];
if（pfVertices [iCurrentIndex]> fMaxX）
fMaxX = pfVertices [iCurrentIndex];
if（pfVertices [iCurrentIndex + 1]> fMaxY）
fMaxY = pfVertices [iCurrentIndex + 1];
if（pfVertices [iCurrentIndex + 2]> fMaxZ）
fMaxZ = pfVertices [iCurrentIndex + 2];
}
//通过绘制膨胀的最小最大值创建一个轴对齐的边界框
//，我们收集
//使用索引基元的例子
glDisable（GL_CULL_FACE）;
GLfloat vertices [] = {
fMinX - 2.0，fMaxY + 2.0，fMaxZ + 2.0，
fMaxX + 2.0，fMaxY + 2.0，fMaxZ + 2.0，
fMaxX + 2.0，fMinY-2.0，fMaxZ + 2.0，
fMinX-2.0，fMinY-2.0，fMaxZ + 2.0，
fMinX-2.0，fMaxY + 2.0，fMinZ-2.0，
fMaxX + 2.0，fMaxY + 2.0，fMinZ-2.0，
fMaxX + 2.0，fMinY-2.0，fMinZ-2.0，
fMinX -2.0，fMinY -2.0，fMinZ- 2.0
}
GLint indices [] = {
0，1，2，3，
4，5，1，0，
3，2，6，7，
5，4，7，6，
1，5，6，2，
4，0，3，7
}
glColor3f（1.0f，1.0f，1.0f）;
glEnableClientState（GL_VERTEX_ARRAY）;
glVertexPointer（3，GL_FLOAT，0，（void *）vertices）;
glDrawElements（GL_QUADS，24，GL_UNSIGNED_INT，（void *）indices）;
glDisableClientState（GL_VERTEX_ARRAY）;
glEnable（GL_CULL_FACE）;
I have the following problem:
Here is how I draw a cube on the screen:
void drawCube()
{
//glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear color and depth buffers
glPushAttrib(GL_POLYGON_BIT | GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT) ;
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE) ;
//glDisable(GL_LIGHTING) ;
glBegin(GL_QUADS); // Begin drawing the color cube with size 3cm x 3.5cm x 4cm
// Top face (y = 1.0f)
// Define vertices in counter-clockwise (CCW) order with normal pointing out
glColor3f(0.0f, 1.0f, 0.0f); // Green
glVertex3f( 1.75f, 1.75f, -4.0f);
glVertex3f(-1.75f, 1.75f, -4.0f);
glVertex3f(-1.75f, 1.75f, 1.0f);
glVertex3f( 1.75f, 1.75f, 1.0f);
// Bottom face (y = -1.0f)
glColor3f(1.0f, 0.5f, 0.0f); // Orange
glVertex3f( 1.75f, -1.75f, 1.0f);
glVertex3f(-1.75f, -1.75f, 1.0f);
glVertex3f(-1.75f, -1.75f, -4.0f);
glVertex3f( 1.75f, -1.75f, -4.0f);
// Front face (z = 1.0f)
glColor3f(1.0f, 0.0f, 0.0f); // Red
glVertex3f( 1.75f, 1.75f, 1.0f);
glVertex3f(-1.75f, 1.75f, 1.0f);
glVertex3f(-1.75f, -1.75f, 1.0f);
glVertex3f( 1.75f, -1.75f, 1.0f);
// Back face (z = -1.0f)
glColor3f(1.0f, 1.0f, 0.0f); // Yellow
glVertex3f( 1.75f, -1.75f, -4.0f);
glVertex3f(-1.75f, -1.75f, -4.0f);
glVertex3f(-1.75f, 1.75f, -4.0f);
glVertex3f( 1.75f, 1.75f, -4.0f);
// Left face (x = -1.0f)
glColor3f(0.0f, 0.0f, 1.0f); // Blue
glVertex3f(-1.75f, 1.75f, 1.0f);
glVertex3f(-1.75f, 1.75f, -4.0f);
glVertex3f(-1.75f, -1.75f, -4.0f);
glVertex3f(-1.75f, -1.75f, 1.0f);
// Right face (x = 1.0f)
glColor3f(1.0f, 0.0f, 1.0f); // Magenta
glVertex3f(1.75f, 1.75f, -4.0f);
glVertex3f(1.75f, 1.75f, 1.0f);
glVertex3f(1.75f, -1.75f, 1.0f);
glVertex3f(1.75f, -1.75f, -4.0f);
glEnd(); // End of drawing color-cube
glPopAttrib() ;
}
The question is how can I assign 'sample points' between all vertices?
From my understanding I need to find the distance between vertices and divide it into (say) five equal parts. For the sake of argument, imagine that the space between two vertices is 1, so 5 points will be placed on 0.2 distance from each other. Also they need to be stored in kind of a memory structure (vector/array) so that each one of them can be accessed and translated into screen coordinates at a later stage.
However, how can I do this in C++ in a totally generic way so that it could be applied basically to any distance metrics?
Here is how the cube looks like
解决方案 Here is my drawBox function, if you want you can modify it to draw different color at each face.
void DrawBox(GLfloat fWidth,GLfloat fHeight,GLfloat fDepth,GLint wslices,GLint dslices,GLint stacks)
{
// Calculate number of primitives on each side of box
// because we can use different tessalation configurations
// we must calculate separate group of box sides
int iTopButtonQuads = wslices * dslices * 2; // Calculate number of quads in top and button sides
int iLeftRightQuads = dslices * stacks * 2; // Calculate number of quads in left and right sides
int iFrontBackQuads = wslices * stacks * 2; // Calculate number of quads in front and back sides
// If we consider to use quads as primitive then each primitive will
// have 4 points, and each point has color, coord and normal attribute.
// So we create separate array to contain each attibute values.
float* pfVertices = new float[(iTopButtonQuads + iLeftRightQuads + iFrontBackQuads) * 3 * 4];
float* pfColors = new float[(iTopButtonQuads + iLeftRightQuads + iFrontBackQuads) * 3 * 4];
float* pfNormals = new float[(iTopButtonQuads + iLeftRightQuads + iFrontBackQuads) * 3 * 4];
int iVertexIndex = 0;
GLfloat Xstep = fWidth / wslices;
GLfloat Ystep = fHeight / stacks;
GLfloat Zstep = fDepth / dslices;
GLfloat firstX = fWidth / 2.0f;
GLfloat firstY = fHeight / 2.0f;
GLfloat firstZ = fDepth / 2.0f;
GLfloat currX = 0.0f;
GLfloat currY = 0.0f;
GLfloat currZ = 0.0f;
GLfloat x_status = 0.0f;
GLfloat y_status = 0.0f;
GLfloat z_status = 0.0f;
// the bottom and the top of the box
for (currZ = -firstZ, z_status = 0.0f; currZ < firstZ - Zstep / 2.0f; currZ += Zstep, z_status += Zstep)
{
for (currX = -firstX, x_status = 0.0f; currX < firstX - Xstep / 2.0f; currX += Xstep, x_status += Xstep)
{
int iCurrentIndex = iVertexIndex * 3 * 4;
float pfNormal[3] = { 0.0f, -1.0f, 0.0f };
memcpy(pfNormals + iCurrentIndex, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 3, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 6, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 9, pfNormal, 3 * 4);
float pfColor[3] = { 1.0f, 0.0f, 0.0f };
memcpy(pfColors + iCurrentIndex, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 3, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 6, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 9, pfColor, 3 * 4);
float pfVertex0[3] = {currX,-firstY,currZ};
float pfVertex1[3] = {currX + Xstep,-firstY,currZ};
float pfVertex2[3] = {currX + Xstep,-firstY,currZ + Zstep};
float pfVertex3[3] = {currX,-firstY,currZ + Zstep};
memcpy(pfVertices + iCurrentIndex, pfVertex0, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 3, pfVertex1, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 6, pfVertex2, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 9, pfVertex3, 3 * 4);
iVertexIndex++;
}
for (currX = -firstX, x_status = 0.0f; currX < firstX - Xstep / 2.0f; currX += Xstep, x_status += Xstep)
{
int iCurrentIndex = iVertexIndex * 3 * 4;
float pfNormal[3] = { 0.0f, 1.0f, 0.0f };
memcpy(pfNormals + iCurrentIndex, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 3, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 6, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 9, pfNormal, 3 * 4);
float pfColor[3] = { 0.0f, 1.0f, 0.0f };
memcpy(pfColors + iCurrentIndex, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 3, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 6, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 9, pfColor, 3 * 4);
float pfVertex0[3] = {currX + Xstep,firstY,currZ + Zstep};
float pfVertex1[3] = {currX + Xstep,firstY,currZ};
float pfVertex2[3] = {currX,firstY,currZ};
float pfVertex3[3] = {currX,firstY,currZ + Zstep};
memcpy(pfVertices + iCurrentIndex, pfVertex0, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 3, pfVertex1, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 6, pfVertex2, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 9, pfVertex3, 3 * 4);
iVertexIndex++;
}
}
// the front and the back of the box
for (currY = -firstY, y_status = 0.0f; currY < firstY - Ystep / 2.0f ; currY += Ystep, y_status += Ystep)
{
for (currX = -firstX, x_status = 0.0f; currX < firstX - Xstep / 2.0f; currX += Xstep, x_status += Xstep)
{
int iCurrentIndex = iVertexIndex * 3 * 4;
float pfNormal[3] = { 0.0f, 0.0f, 1.0f };
memcpy(pfNormals + iCurrentIndex, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 3, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 6, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 9, pfNormal, 3 * 4);
float pfColor[3] = { 0.0f, 0.0f, 1.0f };
memcpy(pfColors + iCurrentIndex, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 3, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 6, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 9, pfColor, 3 * 4);
float pfVertex0[3] = {currX,currY,firstZ};
float pfVertex1[3] = {currX + Xstep,currY,firstZ};
float pfVertex2[3] = {currX + Xstep,currY + Ystep,firstZ};
float pfVertex3[3] = {currX,currY + Ystep,firstZ};
memcpy(pfVertices + iCurrentIndex, pfVertex0, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 3, pfVertex1, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 6, pfVertex2, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 9, pfVertex3, 3 * 4);
iVertexIndex++;
}
for (currX = -firstX, x_status = 0.0f; currX < firstX - Xstep / 2.0f; currX += Xstep, x_status += Xstep)
{
int iCurrentIndex = iVertexIndex * 3 * 4;
float pfNormal[3] = { 0.0f, 0.0f, -1.0f };
memcpy(pfNormals + iCurrentIndex, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 3, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 6, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 9, pfNormal, 3 * 4);
float pfColor[3] = { 0.0f, 1.0f, 1.0f };
memcpy(pfColors + iCurrentIndex, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 3, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 6, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 9, pfColor, 3 * 4);
float pfVertex0[3] = {currX + Xstep,currY + Ystep,-firstZ};
float pfVertex1[3] = {currX + Xstep,currY,-firstZ};
float pfVertex2[3] = {currX,currY,-firstZ};
float pfVertex3[3] = {currX,currY + Ystep,-firstZ};
memcpy(pfVertices + iCurrentIndex, pfVertex0, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 3, pfVertex1, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 6, pfVertex2, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 9, pfVertex3, 3 * 4);
iVertexIndex++;
}
}
// Right side and the left side of the box
for (currY = -firstY, y_status = 0.0f; currY < firstY - Ystep / 2.0f; currY += Ystep, y_status += Ystep)
{
for (currZ = -firstZ, z_status = 0.0f; currZ < firstZ - Zstep / 2.0f; currZ += Zstep, z_status += Zstep)
{
int iCurrentIndex = iVertexIndex * 3 * 4;
float pfNormal[3] = { 1.0f, 0.0f, 0.0f };
memcpy(pfNormals + iCurrentIndex, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 3, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 6, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 9, pfNormal, 3 * 4);
float pfColor[3] = { 1.0f, 0.0f, 1.0f };
memcpy(pfColors + iCurrentIndex, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 3, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 6, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 9, pfColor, 3 * 4);
float pfVertex0[3] = {firstX,currY,currZ};
float pfVertex1[3] = {firstX,currY + Ystep,currZ};
float pfVertex2[3] = {firstX,currY + Ystep,currZ + Zstep};
float pfVertex3[3] = {firstX,currY,currZ + Zstep};
memcpy(pfVertices + iCurrentIndex, pfVertex0, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 3, pfVertex1, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 6, pfVertex2, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 9, pfVertex3, 3 * 4);
iVertexIndex++;
}
for (currZ = -firstZ, z_status = 0.0f; currZ < firstZ - Zstep / 2.0f; currZ += Zstep, z_status += Zstep)
{
int iCurrentIndex = iVertexIndex * 3 * 4;
float pfNormal[3] = { -1.0f, 0.0f, 0.0f };
memcpy(pfNormals + iCurrentIndex, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 3, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 6, pfNormal, 3 * 4);
memcpy(pfNormals + iCurrentIndex + 9, pfNormal, 3 * 4);
float pfColor[3] = { 1.0f, 1.0f, 0.0f };
memcpy(pfColors + iCurrentIndex, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 3, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 6, pfColor, 3 * 4);
memcpy(pfColors + iCurrentIndex + 9, pfColor, 3 * 4);
float pfVertex0[3] = {-firstX,currY,currZ};
float pfVertex1[3] = {-firstX,currY,currZ + Zstep};
float pfVertex2[3] = {-firstX,currY + Ystep,currZ + Zstep};
float pfVertex3[3] = {-firstX,currY + Ystep,currZ};
memcpy(pfVertices + iCurrentIndex, pfVertex0, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 3, pfVertex1, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 6, pfVertex2, 3 * 4);
memcpy(pfVertices + iCurrentIndex + 9, pfVertex3, 3 * 4);
iVertexIndex++;
}
}
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glEnableClientState(GL_NORMAL_ARRAY);
glColorPointer(3, GL_FLOAT, 0, (void*)pfColors);
glNormalPointer(GL_FLOAT, 0, (void*)pfNormals);
glVertexPointer(3, GL_FLOAT, 0, (void*)pfVertices);
glDrawArrays(GL_QUADS, 0, (iTopButtonQuads + iLeftRightQuads + iFrontBackQuads) * 4);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
glDisableClientState(GL_NORMAL_ARRAY);
delete [] pfVertices;
delete [] pfNormals;
delete [] pfColors;
}
the result will be like
this is the example of usage created arrays, to collect some shape statistics
// Example
// Find min-max of shapes coordinates
// Get coord of first vertex
float fMinX = pfVertices[0];
float fMinY = pfVertices[1];
float fMinZ = pfVertices[2];
float fMaxX = pfVertices[0];
float fMaxY = pfVertices[1];
float fMaxZ = pfVertices[2];
for (int iVertexIndex = 0; iVertexIndex < (iTopButtonQuads + iLeftRightQuads + iFrontBackQuads) * 4; iVertexIndex++)
{
int iCurrentIndex = iVertexIndex * 3; // (x y z) per vertex
if (pfVertices[iCurrentIndex] < fMinX)
fMinX = pfVertices[iCurrentIndex];
if (pfVertices[iCurrentIndex + 1] < fMinY)
fMinY = pfVertices[iCurrentIndex + 1];
if (pfVertices[iCurrentIndex + 2] < fMinZ)
fMinZ = pfVertices[iCurrentIndex + 2];
if (pfVertices[iCurrentIndex] > fMaxX)
fMaxX = pfVertices[iCurrentIndex];
if (pfVertices[iCurrentIndex + 1] > fMaxY)
fMaxY = pfVertices[iCurrentIndex + 1];
if (pfVertices[iCurrentIndex + 2] > fMaxZ)
fMaxZ = pfVertices[iCurrentIndex + 2];
}
// Create an axes aligned bounding box
// by simply drawing inflated min-maxes, that we collect
// example of using indexed primitives
glDisable(GL_CULL_FACE);
GLfloat vertices[] = {
fMinX - 2.0, fMaxY + 2.0, fMaxZ + 2.0,
fMaxX + 2.0, fMaxY + 2.0, fMaxZ + 2.0,
fMaxX + 2.0, fMinY - 2.0, fMaxZ + 2.0,
fMinX - 2.0, fMinY - 2.0, fMaxZ + 2.0,
fMinX - 2.0, fMaxY + 2.0, fMinZ - 2.0,
fMaxX + 2.0, fMaxY + 2.0, fMinZ - 2.0,
fMaxX + 2.0, fMinY - 2.0, fMinZ - 2.0,
fMinX - 2.0, fMinY - 2.0, fMinZ - 2.0
};
GLint indices[] = {
0, 1, 2, 3,
4, 5, 1, 0,
3, 2, 6, 7,
5, 4, 7, 6,
1, 5, 6, 2,
4, 0, 3, 7
};
glColor3f(1.0f, 1.0f, 1.0f);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, 0, (void*)vertices);
glDrawElements(GL_QUADS, 24, GL_UNSIGNED_INT, (void*)indices);
glDisableClientState(GL_VERTEX_ARRAY);
glEnable(GL_CULL_FACE);
这篇关于表面细分的理论和算法的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
