[ Opengl ] Lighting
Lighting
라이팅을 위해 suface normal, vertex normal을 계산한다.
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void Renderer ::makefaceNormals() //외적
{
for (int i = 0; i < m_nNumFace; i++) // 각 face의 normal
{
Vector4 v1, v2;
v1.x = m_vertex[m_face[i].m_vertex[0] - 1][0] - m_vertex[m_face[i].m_vertex[1] - 1][0];
v1.y = m_vertex[m_face[i].m_vertex[0] - 1][1] - m_vertex[m_face[i].m_vertex[1] - 1][1];
v1.z = m_vertex[m_face[i].m_vertex[0] - 1][2] - m_vertex[m_face[i].m_vertex[1] - 1][2];
v2.x = m_vertex[m_face[i].m_vertex[1] - 1][0] - m_vertex[m_face[i].m_vertex[2] - 1][0];
v2.y = m_vertex[m_face[i].m_vertex[1] - 1][1] - m_vertex[m_face[i].m_vertex[2] - 1][1];
v2.z = m_vertex[m_face[i].m_vertex[1] - 1][2] - m_vertex[m_face[i].m_vertex[2] - 1][2];
Vector4 ret;
ret = crossProduct(v1, v2);
ret = normalize(ret);
m_faceNormal[i][0] = ret.x;
m_faceNormal[i][1] = ret.y;
m_faceNormal[i][2] = ret.z;
}
}
void Renderer::makeVertexNormals()
{
for (int i = 0; i < m_nNumFace; i++) // //점의 노말은 점이 속한 삼각형 노말의 평균
{
for (int j = 0; j < 3; j++)
{
m_vertexNormal[m_face[i].m_vertex[j] - 1][0] += m_faceNormal[i][0];
m_vertexNormal[m_face[i].m_vertex[j] - 1][1] += m_faceNormal[i][1];
m_vertexNormal[m_face[i].m_vertex[j] - 1][2] += m_faceNormal[i][2];
}
}
for (int i = 0; i < m_nNumVertex; i++)
{
Vector4 v;
v.x = m_vertexNormal[i][0];
v.y = m_vertexNormal[i][1];
v.z = m_vertexNormal[i][2];
v = normalize(v);
m_vertexNormal[i][0] = v.x;
m_vertexNormal[i][1] = v.y;
m_vertexNormal[i][2] = v.z;
}
}
광원을 지정하고 빛벡터를 생성한다.
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Vector4 directionLight(5.f, 5.f, 5.f);
Vector4 ndirectionLight = normalize(directionLight);
엣지 테이블에 노말을 추가하고 빛의 강도에 따른 계산을 진행하여 라이팅을 적용해 렌더링한다.
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void Renderer::buildEdgetable(int nFace)
{
float vertices[2][3] = { 0 };
float uvVertices[2][2] = { 0 };
float nVertices[2][3] = { 0 };
float lightVertices[2][3] = { 0 };
int ymin = 0;
float savedY = 0;
float yMax = 0;
for (int i = 0; i < m_face[nFace].m_nNumVertex; i++)
{
for (int j = 0; j < 3; j++)
{
vertices[0][j] = m_tramsformedVertex[m_face[nFace].m_vertex[i] - 1][j];
vertices[1][j] = m_tramsformedVertex[m_face[nFace].m_vertex[(i + 1) % m_face[nFace].m_nNumVertex] - 1][j];
nVertices[0][j] = m_faceNormal[nFace][j];
nVertices[1][j] = m_faceNormal[nFace][j];
}
for (int j = 0; j < 2; j++)
{
uvVertices[0][j] = m_uv[m_face[nFace].m_vertex[i] - 1][j];
uvVertices[1][j] = m_uv[m_face[nFace].m_vertex[(i + 1) % m_face[nFace].m_nNumVertex] - 1][j];
}
if (vertices[0][1] == vertices[1][1]) continue;
if (vertices[0][1] < vertices[1][1]) // 작을때 ceiling 클 때 floor
{
savedY = vertices[0][1];
ymin = ceil(vertices[0][1]);
ymin = max(ymin, 0);
if (ymin > checkImageHeight - 1) continue;
m_ET[ymin][m_indexCount[ymin]].xperY = (vertices[1][0] - vertices[0][0]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].zPerY = (vertices[1][2] - vertices[0][2]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].uPerY = (uvVertices[1][0] - uvVertices[0][0]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].vPerY = (uvVertices[1][1] - uvVertices[0][1]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].nxPerY = (nVertices[1][0] - nVertices[0][0]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].nyPerY = (nVertices[1][1] - nVertices[0][1]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].nzPerY = (nVertices[1][2] - nVertices[0][2]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].yMax = vertices[1][1];
m_ET[ymin][m_indexCount[ymin]].x = vertices[0][0];
m_ET[ymin][m_indexCount[ymin]].z = vertices[0][2];
m_ET[ymin][m_indexCount[ymin]].u = uvVertices[0][0];
m_ET[ymin][m_indexCount[ymin]].v = uvVertices[0][1];
m_ET[ymin][m_indexCount[ymin]].nx = nVertices[0][0];
m_ET[ymin][m_indexCount[ymin]].ny = nVertices[0][1];
m_ET[ymin][m_indexCount[ymin]].nz = nVertices[0][2];
if (ymin - savedY != 0)
{
m_ET[ymin][m_indexCount[ymin]].x += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].xperY;
m_ET[ymin][m_indexCount[ymin]].z += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].zPerY;
m_ET[ymin][m_indexCount[ymin]].u += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].uPerY;
m_ET[ymin][m_indexCount[ymin]].v += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].vPerY;
m_ET[ymin][m_indexCount[ymin]].nx += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].nxPerY;
m_ET[ymin][m_indexCount[ymin]].ny += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].nyPerY;
m_ET[ymin][m_indexCount[ymin]].nz += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].nzPerY;
}
}
else
{
savedY = vertices[1][1];
ymin = ceil(vertices[1][1]);
ymin = max(ymin, 0);
if (ymin > checkImageHeight - 1) continue;
m_ET[ymin][m_indexCount[ymin]].xperY = (vertices[1][0] - vertices[0][0]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].zPerY = (vertices[1][2] - vertices[0][2]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].uPerY = (uvVertices[1][0] - uvVertices[0][0]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].vPerY = (uvVertices[1][1] - uvVertices[0][1]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].nxPerY = (nVertices[1][0] - nVertices[0][0]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].nyPerY = (nVertices[1][1] - nVertices[0][1]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].nzPerY = (nVertices[1][2] - nVertices[0][2]) / (vertices[1][1] - vertices[0][1]);
m_ET[ymin][m_indexCount[ymin]].yMax = vertices[0][1];
m_ET[ymin][m_indexCount[ymin]].x = vertices[1][0];
m_ET[ymin][m_indexCount[ymin]].z = vertices[1][2];
m_ET[ymin][m_indexCount[ymin]].u = uvVertices[1][0];
m_ET[ymin][m_indexCount[ymin]].v = uvVertices[1][1];
m_ET[ymin][m_indexCount[ymin]].nx = nVertices[1][0];
m_ET[ymin][m_indexCount[ymin]].ny = nVertices[1][1];
m_ET[ymin][m_indexCount[ymin]].nz = nVertices[1][2];
if (ymin - savedY != 0)
{
m_ET[ymin][m_indexCount[ymin]].x += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].xperY;
m_ET[ymin][m_indexCount[ymin]].z += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].zPerY;
m_ET[ymin][m_indexCount[ymin]].u += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].uPerY;
m_ET[ymin][m_indexCount[ymin]].v += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].vPerY;
m_ET[ymin][m_indexCount[ymin]].nx += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].nxPerY;
m_ET[ymin][m_indexCount[ymin]].ny += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].nyPerY;
m_ET[ymin][m_indexCount[ymin]].nz += (ymin - savedY) * m_ET[ymin][m_indexCount[ymin]].nzPerY;
}
}
m_indexCount[ymin]++;
}
void Renderer::fill(GLubyte color[3])
{
// AET
for (int i = 0; i < checkImageHeight; i++)
{
//update intersection
for (int j = 0; j < m_numEdgeInAET; j++)
{
m_AET[j].x += m_AET[j].xperY;
m_AET[j].z += m_AET[j].zPerY;
m_AET[j].u += m_AET[j].uPerY;
m_AET[j].v += m_AET[j].vPerY;
m_AET[j].nx += m_AET[j].nxPerY;
m_AET[j].ny += m_AET[j].nyPerY;
m_AET[j].nz += m_AET[j].nzPerY;
}
//Add new edge
for (int j = 0; j < m_indexCount[i]; j++)
{
m_AET[m_numEdgeInAET + j] = m_ET[i][j];
}
m_numEdgeInAET += m_indexCount[i];
//Delete edge
for (int j = 0; j < m_numEdgeInAET; j++)
{
if (m_AET[j].yMax < i)
{
for (int k = j; k < m_numEdgeInAET; k++)
{
m_AET[k] = m_AET[k + 1];
}
j--;
m_numEdgeInAET--;
}
}
//Sort intersections
Edge temp;
for (int j = 0; j < m_numEdgeInAET - 1; j++)
{
for (int k = j + 1; k < m_numEdgeInAET; k++)
{
if (m_AET[j].x > m_AET[k].x)
{
temp = m_AET[j];
m_AET[j] = m_AET[k];
m_AET[k] = temp;
}
}
}
//Render
for (int j = 0; j < m_numEdgeInAET; j += 2)
{
int k;
int xmin = floor(m_AET[j].x);
int xmax = floor(m_AET[j + 1].x);
xmin = max(xmin, 0);
xmax = min(xmax, checkImageWidth - 1);
float deltaU = 0; float deltaV = 0; float deltaZ = 0;
float deltaNX = 0; float deltaNY = 0; float deltaNZ = 0;
float uPerX = 0; float vPerX = 0; float zPerX = 0;
float nxPerX = 0; float nyPerX = 0; float nzPerX = 0;
float lxPerX = 0; float lyPerNY = 0; float lzPerNZ = 0;
float deltaLX = 0; float deltaLY = 0; float deltaLZ = 0;
float sx, sy, sz; float scala = 0;
uPerX = (m_AET[j + 1].u - m_AET[j].u) / (m_AET[j + 1].x - m_AET[j].x);
vPerX = (m_AET[j + 1].v - m_AET[j].v) / (m_AET[j + 1].x - m_AET[j].x);
zPerX = (m_AET[j + 1].z - m_AET[j].z) / (m_AET[j + 1].x - m_AET[j].x);
nxPerX = (m_AET[j + 1].nx - m_AET[j].nx) / (m_AET[j + 1].x - m_AET[j].x);
nyPerX = (m_AET[j + 1].ny - m_AET[j].ny) / (m_AET[j + 1].x - m_AET[j].x);
nzPerX = (m_AET[j + 1].nz - m_AET[j].nz) / (m_AET[j + 1].x - m_AET[j].x);
for (k = xmin; k < xmax; k++)
{
sx = (m_AET[j].nx + deltaNX) * (ndirectionLight.x);
sy = (m_AET[j].ny + deltaNY) * (ndirectionLight.y);
sz = (m_AET[j].nz + deltaNZ) * (ndirectionLight.z);
// 빛의 영향을 계산을 위한 스칼라
scala = sx + sy + sz;
if (m_AET[j].z + deltaZ < m_zBuffer[i][k])
{
checkImage[i][k][0] = (GLubyte)m_texture[(int)(m_AET[j].v + deltaV)][(int)(m_AET[j].u + deltaU)][0] * max(scala, 0.f);
checkImage[i][k][1] = (GLubyte)m_texture[(int)(m_AET[j].v + deltaV)][(int)(m_AET[j].u + deltaU)][1] * max(scala, 0.f);
checkImage[i][k][2] = (GLubyte)m_texture[(int)(m_AET[j].v + deltaV)][(int)(m_AET[j].u + deltaU)][2] * max(scala, 0.f);
m_zBuffer[i][k] = m_AET[j].z + deltaZ;
}
deltaU += uPerX;
deltaV += vPerX;
deltaZ += zPerX;
deltaNX += nxPerX;
deltaNY += nyPerX;
deltaNZ += nzPerX;
}
}
}
}
출력
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