diff options
author | Jacques Lucke <jacques@blender.org> | 2022-07-06 16:20:25 +0300 |
---|---|---|
committer | Jacques Lucke <jacques@blender.org> | 2022-07-06 16:20:38 +0300 |
commit | 6636edbb00942a1a04bdf6f3cb843a1636ffa8b4 (patch) | |
tree | 5422071afb9287b0980e800a9a77e5c915884863 /source | |
parent | 9d0777e5144e6d1ee154e03a7cd4272468cdb422 (diff) |
BLI: improve reverse uv sample in edge cases
Allow for a small epsilon to improve handling of uvs that are on edges.
Generally, when using reverse uv sampling, we expect that the sampling
is supposed to succeed.
Diffstat (limited to 'source')
-rw-r--r-- | source/blender/geometry/intern/reverse_uv_sampler.cc | 29 |
1 files changed, 27 insertions, 2 deletions
diff --git a/source/blender/geometry/intern/reverse_uv_sampler.cc b/source/blender/geometry/intern/reverse_uv_sampler.cc index 87ba2c77657..54df43db4ea 100644 --- a/source/blender/geometry/intern/reverse_uv_sampler.cc +++ b/source/blender/geometry/intern/reverse_uv_sampler.cc @@ -45,6 +45,11 @@ ReverseUVSampler::Result ReverseUVSampler::sample(const float2 &query_uv) const { const int2 cell_key = uv_to_cell_key(query_uv, resolution_); const Span<int> looptri_indices = looptris_by_cell_.lookup(cell_key); + + float best_dist = FLT_MAX; + float3 best_bary_weights; + const MLoopTri *best_looptri; + for (const int looptri_index : looptri_indices) { const MLoopTri &looptri = looptris_[looptri_index]; const float2 &uv_0 = uv_map_[looptri.tri[0]]; @@ -54,11 +59,31 @@ ReverseUVSampler::Result ReverseUVSampler::sample(const float2 &query_uv) const if (!barycentric_coords_v2(uv_0, uv_1, uv_2, query_uv, bary_weights)) { continue; } - if (IN_RANGE_INCL(bary_weights.x, 0.0f, 1.0f) && IN_RANGE_INCL(bary_weights.y, 0.0f, 1.0f) && - IN_RANGE_INCL(bary_weights.z, 0.0f, 1.0f)) { + + /* If #query_uv is in the triangle, the distance is <= 0. Otherwise, the larger the distance, + * the further away the uv is from the triangle. */ + const float x_dist = std::max(-bary_weights.x, bary_weights.x - 1.0f); + const float y_dist = std::max(-bary_weights.y, bary_weights.y - 1.0f); + const float z_dist = std::max(-bary_weights.z, bary_weights.z - 1.0f); + const float dist = MAX3(x_dist, y_dist, z_dist); + + if (dist <= 0.0f) { + /* Return early if the uv coordinate is in the triangle. */ return Result{ResultType::Ok, &looptri, bary_weights}; } + + if (dist < best_dist) { + best_dist = dist; + best_bary_weights = bary_weights; + best_looptri = &looptri; + } + } + + /* Allow for a small epsilon in case the uv is on th edge. */ + if (best_dist < 0.00001f) { + return Result{ResultType::Ok, best_looptri, math::clamp(best_bary_weights, 0.0f, 1.0f)}; } + return Result{}; } |