phaneron/Kelsidavis-WoWee
1
0
Fork 0
mirror of https://github.com/Kelsidavis/WoWee.git synced 2026-05-08 10:03:51 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 2

feat(editor): add --export-mesh-heightmap, inverse of gen-mesh-from-heightmap

Browse source 
Extracts a grayscale heightmap PNG from a row-major W×H heightmap
mesh. Y values are normalized to 0..255 using the mesh bounds so
the output PNG uses the full dynamic range.

User supplies W and H explicitly: arbitrary meshes aren't
necessarily heightmap-shaped, and taking the dimensions as args
avoids guessing wrong on a mesh with vertex count W*H but a
different layout.

Round-trips with --gen-mesh-from-heightmap modulo the 1-byte
quantization step.

Verified: noise PNG (32×32) → heightmap mesh → exported PNG (32×32)
chain executes cleanly, height 0..1.984 mapped to 0..255 grayscale,
both PNGs share the same dimensions. Brings command count to 230.
This commit is contained in:
Kelsi 2026-05-07 08:46:50 -07:00
parent d54440a75b
commit ca8c366870
1 changed files with 87 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

88
tools/editor/main.cpp
View file

@ -545,6 +545,8 @@ static void printUsage(const char* argv0) {
std::printf(" Procedural straight staircase along +X with N steps (default 5 / 0.2 / 0.3 / 1.0)\n");
std::printf(" --gen-mesh-from-heightmap <wom-base> <heightmap.png> [scaleXZ] [scaleY]\n");
std::printf(" Convert a grayscale PNG into a heightmap mesh (W×H verts, 2(W-1)(H-1) tris)\n");
std::printf(" --export-mesh-heightmap <wom-base> <out.png> <W> <H>\n");
std::printf(" Extract a grayscale heightmap PNG from a row-major W×H heightmap mesh\n");
std::printf(" --add-texture-to-mesh <wom-base> <png-path> [batchIdx]\n");
std::printf(" Bind an existing PNG into a WOM's texturePaths and point batchIdx (default 0) at it\n");
std::printf(" --scale-mesh <wom-base> <factor>\n");
@ -984,7 +986,7 @@ int main(int argc, char* argv[]) {
"--export-data-tree-md", "--gen-texture", "--gen-mesh", "--gen-mesh-textured",
"--add-texture-to-mesh", "--add-texture-to-zone",
"--gen-mesh-stairs", "--gen-texture-gradient",
"--gen-mesh-from-heightmap",
"--gen-mesh-from-heightmap", "--export-mesh-heightmap",
"--scale-mesh", "--translate-mesh", "--strip-mesh",
"--gen-texture-noise", "--rotate-mesh",
"--center-mesh", "--flip-mesh-normals", "--mirror-mesh",
@ -16654,6 +16656,90 @@ int main(int argc, char* argv[]) {
std::printf(" vertices : %zu\n", wom.vertices.size());
std::printf(" triangles : %zu\n", wom.indices.size() / 3);
return 0;
} else if (std::strcmp(argv[i], "--export-mesh-heightmap") == 0 && i + 4 < argc) {
// Inverse of --gen-mesh-from-heightmap: extract a
// grayscale PNG from a row-major W×H heightmap mesh.
// The user supplies W and H since arbitrary meshes
// aren't necessarily heightmap-shaped — taking the
// dimensions explicitly avoids guessing wrong on a
// mesh with vertex count W*H but a different layout.
//
// Y values are normalized to 0..255 using the mesh
// bounds (Y_min → 0, Y_max → 255). Round-trips with
// --gen-mesh-from-heightmap modulo the 1-byte
// quantization step.
std::string womBase = argv[++i];
std::string outPath = argv[++i];
int W = 0, H = 0;
try {
W = std::stoi(argv[++i]);
H = std::stoi(argv[++i]);
} catch (...) {
std::fprintf(stderr,
"export-mesh-heightmap: W and H must be integers\n");
return 1;
}
if (W < 2 || H < 2 || W > 8192 || H > 8192) {
std::fprintf(stderr,
"export-mesh-heightmap: W and H must be 2..8192\n");
return 1;
}
if (womBase.size() >= 4 &&
womBase.substr(womBase.size() - 4) == ".wom") {
womBase = womBase.substr(0, womBase.size() - 4);
}
if (!wowee::pipeline::WoweeModelLoader::exists(womBase)) {
std::fprintf(stderr,
"export-mesh-heightmap: %s.wom does not exist\n",
womBase.c_str());
return 1;
}
auto wom = wowee::pipeline::WoweeModelLoader::load(womBase);
if (!wom.isValid()) {
std::fprintf(stderr,
"export-mesh-heightmap: failed to load %s.wom\n",
womBase.c_str());
return 1;
}
size_t expected = static_cast<size_t>(W) * H;
if (wom.vertices.size() < expected) {
std::fprintf(stderr,
"export-mesh-heightmap: %s.wom has %zu vertices, "
"need at least %zu for %dx%d\n",
womBase.c_str(), wom.vertices.size(), expected, W, H);
return 1;
}
float yMin = wom.boundMin.y;
float yMax = wom.boundMax.y;
float range = yMax - yMin;
std::vector<uint8_t> pixels(expected * 3, 0);
for (int y = 0; y < H; ++y) {
for (int x = 0; x < W; ++x) {
size_t idx = static_cast<size_t>(y) * W + x;
float h = wom.vertices[idx].position.y;
float t = (range > 1e-6f) ? (h - yMin) / range : 0.0f;
if (t < 0) t = 0; if (t > 1) t = 1;
uint8_t g = static_cast<uint8_t>(t * 255.0f + 0.5f);
size_t i2 = idx * 3;
pixels[i2 + 0] = g;
pixels[i2 + 1] = g;
pixels[i2 + 2] = g;
}
}
if (!stbi_write_png(outPath.c_str(), W, H, 3,
pixels.data(), W * 3)) {
std::fprintf(stderr,
"export-mesh-heightmap: stbi_write_png failed for %s\n",
outPath.c_str());
return 1;
}
std::printf("Wrote %s from %s.wom\n",
outPath.c_str(), womBase.c_str());
std::printf(" size : %dx%d\n", W, H);
std::printf(" height : %.3f to %.3f (mapped to 0..255)\n",
yMin, yMax);
std::printf(" pixels : %zu (W*H)\n", expected);
return 0;
} else if (std::strcmp(argv[i], "--add-texture-to-mesh") == 0 && i + 2 < argc) {
// Manual companion to --gen-mesh-textured. Binds an
// existing PNG to a WOM by appending it to texturePaths