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我想畫一個球體用C++其做用下面的代碼工作和DirectX：DirectX 9的頂點球
struct Vertex
{
D3DXVECTOR3 position; //float x, y, z;
DWORD color;
};
void myApp::createAndFillVertexBuffer(){
int radius = 1;
float slices = 50;
float stacks = 50;
float sliceStep = 2*D3DX_PI/slices;
float stackStep = D3DX_PI/stacks;
int vertexCount = slices * (stacks - 1) + 2;
primitiveCount = slices * (stacks - 1) * 2;
m_D3DDev->CreateVertexBuffer(
sizeof(Vertex)*vertexCount,
D3DUSAGE_WRITEONLY,
D3DFVF_M_VERTEX,
D3DPOOL_DEFAULT,
&m_VB,
NULL);
Vertex *m_MVB;
HRESULT hRes = m_VB->Lock(0,0,(void**)&m_MVB,0);
if (hRes == D3D_OK)
{
int currentVertex = 0;
m_MVB[currentVertex++].position = D3DXVECTOR3(0.0f, -radius, 0.0f);
float stackAngle = D3DX_PI - stackStep;
for (int i = 0; i < stacks - 1; i++)
{
float sliceAngle = 0;
for (int j = 0; j < slices; j++)
{
float x = (float)(radius * sinf(stackAngle) * cosf(sliceAngle));
float y = (float)(radius * cosf(stackAngle));
float z = (float)(radius * sinf(stackAngle) * sinf(sliceAngle));
m_MVB[currentVertex].position = D3DXVECTOR3(x,y,z);
m_MVB[currentVertex].color = D3DCOLOR_XRGB(255,200,100);
currentVertex++;
sliceAngle += sliceStep;
}
stackAngle -= stackStep;
}
m_MVB[currentVertex++].position = D3DXVECTOR3(0.0f, radius, 0.0f);
m_VB->Unlock();
}
}
我創建一個使用頂點球，我應該只使用頂點做到這一點，不是D3DXCreateSphere()方法。 我得到了下面顯示的奇怪結果。我究竟做錯了什麼？
這是我想要的結果：
UPDATE：
我嘗試了一些更多的樣本，但它的工作是錯誤的。 我試圖添加indexBuffer到我的算法。這裏產生的算法，但它也工作錯誤：
int number_of_vertices, number_of_faces;
int slices= 20;
int stacks = 20;
float phi_step, phi_start;
float theta_step, theta, sin_theta, cos_theta;
int vertex, face;
int slice, stack;
number_of_vertices = 2 + slices * (stacks-1);
number_of_faces = 2 * slices + (stacks - 2) * (2 * slices);
primitiveCount = number_of_faces;
m_D3DDev->CreateVertexBuffer(
sizeof(Vertex)*number_of_vertices,
D3DUSAGE_WRITEONLY,
D3DFVF_M_VERTEX,
D3DPOOL_DEFAULT,
&m_VB,
NULL);
m_D3DDev->CreateIndexBuffer(sizeof(int) * number_of_faces*3,
D3DUSAGE_WRITEONLY,
D3DFMT_INDEX32,
D3DPOOL_DEFAULT,
&pIbuf,
NULL);
Vertex *vertices;
HRESULT hRes = m_VB->Lock(0,0,(void**)&vertices,0);
WORD *faces;
HRESULT hRes2 = pIbuf->Lock(0, 0, (void**)&faces, 0);
if (FAILED(hRes2)) {
return;
}
phi_step = -2 * D3DX_PI/slices;
phi_start = D3DX_PI/2;
theta_step = D3DX_PI/stacks;
theta = theta_step;
vertex = 0;
face = 0;
stack = 0;
vertices[vertex].position.x = 0.0f;
vertices[vertex].position.y = 0.0f;
vertices[vertex].position.z = radius;
vertices[vertex].color = D3DCOLOR_XRGB(255,200,100);
vertex++;
for (stack = 0; stack < stacks - 1; stack++) {
sin_theta = sinf(theta);
cos_theta = cosf(theta);
for (slice = 0; slice < slices; slice++) {
vertices[vertex].normal.x = sin_theta * cosf(phi_start);
vertices[vertex].normal.y = sin_theta * sinf(phi_start);
vertices[vertex].normal.z = cos_theta;
vertices[vertex].position.x = radius * sin_theta * cosf(phi_start);
vertices[vertex].position.y = radius * sin_theta * sinf(phi_start);
vertices[vertex].position.z = radius * cos_theta;
vertices[vertex].color = D3DCOLOR_XRGB(255,200,100);
vertex++;
phi_start += phi_step;
if (slice > 0){
if (stack == 0){
faces[face++] = 0;
faces[face++] = slice + 1;
faces[face++] = slice;
} else {
faces[face++] = sphere_vertex(slices, slice-1, stack-1);
faces[face++] = sphere_vertex(slices, slice, stack-1);
faces[face++] = sphere_vertex(slices, slice-1, stack);
faces[face++] = sphere_vertex(slices, slice, stack-1);
faces[face++] = sphere_vertex(slices, slice, stack);
faces[face++] = sphere_vertex(slices, slice-1, stack);
}
}
}
theta += theta_step;
if (stack == 0) {
faces[face++] = 0;
faces[face++] = 1;
faces[face++] = slice;
}
else {
faces[face++] = sphere_vertex(slices, slice-1, stack-1);
faces[face++] = sphere_vertex(slices, 0, stack-1);
faces[face++] = sphere_vertex(slices, slice-1, stack);
faces[face++] = sphere_vertex(slices, 0, stack-1);
faces[face++] = sphere_vertex(slices, 0, stack);
faces[face++] = sphere_vertex(slices, slice-1, stack);
}
}
vertices[vertex].position.x = 0.0f;
vertices[vertex].position.y = 0.0f;
vertices[vertex].position.z = -radius;
vertices[vertex].color = D3DCOLOR_XRGB(255,200,100);
vertices[vertex].normal.x = 0.0f;
vertices[vertex].normal.y = 0.0f;
vertices[vertex].normal.z = -1.0f;
for (slice = 1; slice < slices; slice++){
faces[face++] = sphere_vertex(slices, slice-1, stack-1);
faces[face++] = sphere_vertex(slices, slice, stack-1);
faces[face++] = vertex;
}
faces[face++] = sphere_vertex(slices, slice-1, stack-1);
faces[face++] = sphere_vertex(slices, 0, stack-1);
faces[face++] = vertex;
m_VB->Unlock();
pIbuf->Unlock();
功能spehereVetrex：
static WORD sphere_vertex(UINT slices, int slice, int stack)
{
return stack*slices+slice+1;
}
然後畫原語：
m_D3DDev->SetStreamSource(0,m_VB,0,sizeof(Vertex));
m_D3DDev->SetIndices(pIbuf);
m_D3DDev->DrawPrimitive(D3DPT_TRIANGLESTRIP,0,primitiveCount);
Vetrex：
#define D3DFVF_M_VERTEX (D3DFVF_XYZ |D3DFVF_NORMAL| D3DFVF_DIFFUSE)
Vetrex結構：
struct Vertex
{
D3DXVECTOR3 position; //float x, y, z;
D3DXVECTOR3 normal;
DWORD color;
};
IDirect3DDevice9 *m_D3DDev;
IDirect3DVertexBuffer9 *m_VB; // Vertex Buffer
IDirect3DIndexBuffer9 *pIbuf;
//config D3DDevice
m_D3DDev->SetRenderState(D3DRS_LIGHTING, false);
m_D3DDev->SetRenderState(D3DRS_ZENABLE, TRUE);
m_D3DDev->SetRenderState(D3DRS_CULLMODE,D3DCULL_NONE);
m_D3DDev->SetFVF(D3DFVF_M_VERTEX);
結果：
我需要製作這樣的東西http://2ch.hk/sn/src/1366328787385.png –
@chris這個？ http://www.backgroundsy.com/file/matte-white-sphere.jpg –
你可以顯示你的渲染調用（繪製原語）？看起來幾何圖形（三角形）沒有正確指定。你使用索引緩衝區嗎？對於這種類型的陰影，還需要在頂點數據中指定曲面法線。也許你應該遵循這個教程：http://msdn.microsoft.com/en-us/library/windows/desktop/bb153261%28v=vs.85%29.aspx – cdoubleplusgood