Fix CSGSphere3D mesh creation

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Aaron Franke 2021-06-18 22:06:29 -04:00
parent 0c68ccecda
commit b2156b22ea
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@ -923,36 +923,40 @@ CSGBrush *CSGSphere3D::_build_brush() {
Ref<Material> *materialsw = materials.ptrw();
bool *invertw = invert.ptrw();
const double lat_step = 1.0 / rings;
const double lon_step = 1.0 / radial_segments;
// We want to follow an order that's convenient for UVs.
// For latitude step we start at the top and move down like in an image.
const double latitude_step = -Math_PI / rings;
const double longitude_step = Math_TAU / radial_segments;
int face = 0;
for (int i = 1; i <= rings; i++) {
double lat0 = Math_PI * (0.5 - (i - 1) * lat_step);
double c0 = Math::cos(lat0);
double s0 = Math::sin(lat0);
double v0 = double(i - 1) / rings;
for (int i = 0; i < rings; i++) {
double latitude0 = latitude_step * i + Math_TAU / 4;
double cos0 = Math::cos(latitude0);
double sin0 = Math::sin(latitude0);
double v0 = double(i) / rings;
double lat1 = Math_PI * (0.5 - i * lat_step);
double c1 = Math::cos(lat1);
double s1 = Math::sin(lat1);
double v1 = double(i) / rings;
double latitude1 = latitude_step * (i + 1) + Math_TAU / 4;
double cos1 = Math::cos(latitude1);
double sin1 = Math::sin(latitude1);
double v1 = double(i + 1) / rings;
for (int j = 1; j <= radial_segments; j++) {
double lng0 = Math_TAU * (0.5 - (j - 1) * lon_step);
double x0 = Math::cos(lng0);
double y0 = Math::sin(lng0);
double u0 = double(j - 1) / radial_segments;
for (int j = 0; j < radial_segments; j++) {
double longitude0 = longitude_step * j;
// We give sin to X and cos to Z on purpose.
// This allows UVs to be CCW on +X so it maps to images well.
double x0 = Math::sin(longitude0);
double z0 = Math::cos(longitude0);
double u0 = double(j) / radial_segments;
double lng1 = Math_TAU * (0.5 - j * lon_step);
double x1 = Math::cos(lng1);
double y1 = Math::sin(lng1);
double u1 = double(j) / radial_segments;
double longitude1 = longitude_step * (j + 1);
double x1 = Math::sin(longitude1);
double z1 = Math::cos(longitude1);
double u1 = double(j + 1) / radial_segments;
Vector3 v[4] = {
Vector3(x0 * c0, s0, y0 * c0) * radius,
Vector3(x1 * c0, s0, y1 * c0) * radius,
Vector3(x1 * c1, s1, y1 * c1) * radius,
Vector3(x0 * c1, s1, y0 * c1) * radius,
Vector3(x0 * cos0, sin0, z0 * cos0) * radius,
Vector3(x1 * cos0, sin0, z1 * cos0) * radius,
Vector3(x1 * cos1, sin1, z1 * cos1) * radius,
Vector3(x0 * cos1, sin1, z0 * cos1) * radius,
};
Vector2 u[4] = {
@ -962,8 +966,8 @@ CSGBrush *CSGSphere3D::_build_brush() {
Vector2(u0, v1),
};
if (i < rings) {
//face 1
// Draw the first face, but skip this at the north pole (i == 0).
if (i > 0) {
facesw[face * 3 + 0] = v[0];
facesw[face * 3 + 1] = v[1];
facesw[face * 3 + 2] = v[2];
@ -979,8 +983,8 @@ CSGBrush *CSGSphere3D::_build_brush() {
face++;
}
if (i > 1) {
//face 2
// Draw the second face, but skip this at the south pole (i == rings - 1).
if (i < rings - 1) {
facesw[face * 3 + 0] = v[2];
facesw[face * 3 + 1] = v[3];
facesw[face * 3 + 2] = v[0];