olegpz
/
ericw-tools
mirror of https://github.com/ericwa/ericw-tools.git
0
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

light: do the phong area/angle weighting by looking at the whole polygon 

without triangulating it. Fixes output on polygons with welded t-junctions
(colinear vertices) which would previously generate 0-area triangles
and have a weight of 0 in the normal smoothing.
This commit is contained in:
Eric Wasylishen 2021-10-22 01:27:28 -06:00
parent b68b370147
commit 0d9275fc53
1 changed files with 36 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
light/phong.cc
View File

@ -604,17 +604,44 @@ void CalculateVertexNormals(const mbsp_t *bsp)
// walk fPlusNeighbours
for (auto f2 : fPlusNeighbours) {
const auto f2_poly = GLM_FacePoints(bsp, f2);
const float f2_area = qv::PolyArea(f2_poly.begin(), f2_poly.end());
const qvec3d f2_norm = Face_Normal(bsp, f2);
/* now just walk around the surface as a triangle fan */
int v1, v2, v3;
v1 = Face_VertexAtIndex(bsp, f2, 0);
v2 = Face_VertexAtIndex(bsp, f2, 1);
for (int j = 2; j < f2->numedges; j++) {
v3 = Face_VertexAtIndex(bsp, f2, j);
AddTriangleNormals(smoothedNormals,
BSP_GetTexinfo(bsp, f2->texinfo), Face_RgbaMiptex(bsp, f2), f2_norm, bsp, v1, v2, v3);
v2 = v3;
// f2 face tangent
auto f2_texinfo = BSP_GetTexinfo(bsp, f2->texinfo);
auto f2_miptex = Face_RgbaMiptex(bsp, f2);
auto f2_p1 = Vertex_GetPos(bsp, Face_VertexAtIndex(bsp, f2, 0));
auto f2_p2 = Vertex_GetPos(bsp, Face_VertexAtIndex(bsp, f2, 1));
auto f2_p3 = Vertex_GetPos(bsp, Face_VertexAtIndex(bsp, f2, 2));
auto f2_uv1 = uvs(f2_texinfo->vecs, f2_p1, f2_miptex->width, f2_miptex->height);
auto f2_uv2 = uvs(f2_texinfo->vecs, f2_p2, f2_miptex->width, f2_miptex->height);
auto f2_uv3 = uvs(f2_texinfo->vecs, f2_p3, f2_miptex->width, f2_miptex->height);
auto f2_tangents = compute_tangents({f2_p1, f2_p2, f2_p3}, {f2_uv1, f2_uv2, f2_uv3});
// walk the vertices of f2, and add their contribution to smoothedNormals
for (int j = 0; j < f2->numedges; j++) {
const int prev_vert_num = Face_VertexAtIndex(bsp, f2, ((j - 1) + f2->numedges) % f2->numedges);
const int curr_vert_num = Face_VertexAtIndex(bsp, f2, j);
const int next_vert_num = Face_VertexAtIndex(bsp, f2, (j + 1) % f2->numedges);
const qvec3f &prev_vert_pos = Vertex_GetPos(bsp, prev_vert_num);
const qvec3f &curr_vert_pos = Vertex_GetPos(bsp, curr_vert_num);
const qvec3f &next_vert_pos = Vertex_GetPos(bsp, next_vert_num);
const float angle_radians = AngleBetweenPoints(prev_vert_pos, curr_vert_pos, next_vert_pos);
float weight = f2_area * angle_radians;
if (!std::isfinite(weight)) {
// TODO: not sure if needed?
weight = 0;
}
auto &n = smoothedNormals[curr_vert_num];
n.normal += f2_norm * weight;
n.tangent += std::get<0>(f2_tangents) * weight;
n.bitangent += std::get<1>(f2_tangents) * weight;
}
}