diff --git a/source/blender/blenlib/BLI_math_matrix.h b/source/blender/blenlib/BLI_math_matrix.h index 2cd2a299d53..c2dafbe3a1a 100644 --- a/source/blender/blenlib/BLI_math_matrix.h +++ b/source/blender/blenlib/BLI_math_matrix.h @@ -238,6 +238,7 @@ bool invert_m3_ex(float m[3][3], float epsilon); bool invert_m3_m3_ex(float m1[3][3], const float m2[3][3], float epsilon); bool invert_m3(float R[3][3]); +bool invert_m2_m2(float R[2][2], const float A[2][2]); bool invert_m3_m3(float R[3][3], const float A[3][3]); bool invert_m4(float R[4][4]); bool invert_m4_m4(float R[4][4], const float A[4][4]); diff --git a/source/blender/blenlib/intern/math_matrix.c b/source/blender/blenlib/intern/math_matrix.c index ce9abc36cad..fcd017b3082 100644 --- a/source/blender/blenlib/intern/math_matrix.c +++ b/source/blender/blenlib/intern/math_matrix.c @@ -1116,6 +1116,22 @@ double determinant_m3_array_db(const double m[3][3]) m[2][0] * (m[0][1] * m[1][2] - m[0][2] * m[1][1])); } +bool invert_m2_m2(float m1[2][2], const float m2[2][2]) +{ + adjoint_m2_m2(m1, m2); + float det = determinant_m2(m2[0][0], m2[1][0], m2[0][1], m2[1][1]); + + bool success = (det != 0.0f); + if (success) { + m1[0][0] /= det; + m1[1][0] /= det; + m1[0][1] /= det; + m1[1][1] /= det; + } + + return success; +} + bool invert_m3_ex(float m[3][3], const float epsilon) { float tmp[3][3]; diff --git a/source/blender/editors/uvedit/uvedit_unwrap_ops.c b/source/blender/editors/uvedit/uvedit_unwrap_ops.c index ae81aaffeb2..7ec80a05f6d 100644 --- a/source/blender/editors/uvedit/uvedit_unwrap_ops.c +++ b/source/blender/editors/uvedit/uvedit_unwrap_ops.c @@ -1191,7 +1191,7 @@ void UV_OT_pack_islands(wmOperatorType *ot) /** \name Average UV Islands Scale Operator * \{ */ -static int average_islands_scale_exec(bContext *C, wmOperator *UNUSED(op)) +static int average_islands_scale_exec(bContext *C, wmOperator *op) { const Scene *scene = CTX_data_scene(C); ViewLayer *view_layer = CTX_data_view_layer(C); @@ -1215,8 +1215,12 @@ static int average_islands_scale_exec(bContext *C, wmOperator *UNUSED(op)) return OPERATOR_CANCELLED; } + /* RNA props */ + const bool scale_uv = RNA_boolean_get(op->ptr, "scale_uv"); + const bool shear = RNA_boolean_get(op->ptr, "shear"); + ParamHandle *handle = construct_param_handle_multi(scene, objects, objects_len, &options); - GEO_uv_parametrizer_average(handle, false); + GEO_uv_parametrizer_average(handle, false, scale_uv, shear); GEO_uv_parametrizer_flush(handle); GEO_uv_parametrizer_delete(handle); @@ -1247,6 +1251,10 @@ void UV_OT_average_islands_scale(wmOperatorType *ot) /* api callbacks */ ot->exec = average_islands_scale_exec; ot->poll = ED_operator_uvedit; + + /* properties */ + RNA_def_boolean(ot->srna, "scale_uv", false, "Non-Uniform", "Scale U and V independently"); + RNA_def_boolean(ot->srna, "shear", false, "Shear", "Reduce shear within islands"); } /** \} */ @@ -1845,7 +1853,7 @@ static void uvedit_unwrap(const Scene *scene, result_info ? &result_info->count_failed : NULL); GEO_uv_parametrizer_lscm_end(handle); - GEO_uv_parametrizer_average(handle, true); + GEO_uv_parametrizer_average(handle, true, false, false); GEO_uv_parametrizer_flush(handle); diff --git a/source/blender/geometry/GEO_uv_parametrizer.h b/source/blender/geometry/GEO_uv_parametrizer.h index 2181f95945e..5285aefbd4c 100644 --- a/source/blender/geometry/GEO_uv_parametrizer.h +++ b/source/blender/geometry/GEO_uv_parametrizer.h @@ -103,7 +103,10 @@ void GEO_uv_parametrizer_pack(ParamHandle *handle, /** \name Average area for all charts * \{ */ -void GEO_uv_parametrizer_average(ParamHandle *handle, bool ignore_pinned); +void GEO_uv_parametrizer_average(ParamHandle *handle, + bool ignore_pinned, + bool scale_uv, + bool shear); /** \} */ diff --git a/source/blender/geometry/intern/uv_parametrizer.c b/source/blender/geometry/intern/uv_parametrizer.c index c75a302f8dc..38eb50722cf 100644 --- a/source/blender/geometry/intern/uv_parametrizer.c +++ b/source/blender/geometry/intern/uv_parametrizer.c @@ -148,7 +148,8 @@ typedef struct PChart { } lscm; struct PChartPack { float rescale, area; - float size[2] /* , trans[2] */; + float size[2]; + float origin[2]; } pack; } u; @@ -4243,7 +4244,10 @@ void GEO_uv_parametrizer_pack(ParamHandle *handle, } } -void GEO_uv_parametrizer_average(ParamHandle *phandle, bool ignore_pinned) +void GEO_uv_parametrizer_average(ParamHandle *phandle, + bool ignore_pinned, + bool scale_uv, + bool shear) { PChart *chart; int i; @@ -4263,6 +4267,83 @@ void GEO_uv_parametrizer_average(ParamHandle *phandle, bool ignore_pinned) continue; } + p_chart_uv_bbox(chart, minv, maxv); + mid_v2_v2v2(chart->u.pack.origin, minv, maxv); + + if (scale_uv || shear) { + /* It's possible that for some "bad" inputs, the following iteration will converge slowly or + * perhaps even diverge. Rather than infinite loop, we only iterate a maximum of `max_iter` + * times. (Also useful when making changes to the calculation.) */ + int max_iter = 10; + for (int j = 0; j < max_iter; j++) { + /* An island could contain millions of polygons. When summing many small values, we need to + * use double precision in the accumulator to maintain accuracy. Note that the individual + * calculations only need to be at single precision.*/ + double scale_cou = 0; + double scale_cov = 0; + double scale_cross = 0; + double weight_sum = 0; + for (PFace *f = chart->faces; f; f = f->nextlink) { + float m[2][2], s[2][2]; + PVert *va = f->edge->vert; + PVert *vb = f->edge->next->vert; + PVert *vc = f->edge->next->next->vert; + s[0][0] = va->uv[0] - vc->uv[0]; + s[0][1] = va->uv[1] - vc->uv[1]; + s[1][0] = vb->uv[0] - vc->uv[0]; + s[1][1] = vb->uv[1] - vc->uv[1]; + /* Find the "U" axis and "V" axis in triangle co-ordinates. Normally this would require + * SVD, but in 2D we can use a cheaper matrix inversion instead.*/ + if (!invert_m2_m2(m, s)) { + continue; + } + float cou[3], cov[3]; /* i.e. Texture "U" and texture "V" in 3D co-ordinates.*/ + for (int i = 0; i < 3; i++) { + cou[i] = m[0][0] * (va->co[i] - vc->co[i]) + m[0][1] * (vb->co[i] - vc->co[i]); + cov[i] = m[1][0] * (va->co[i] - vc->co[i]) + m[1][1] * (vb->co[i] - vc->co[i]); + } + const float weight = p_face_area(f); + scale_cou += len_v3(cou) * weight; + scale_cov += len_v3(cov) * weight; + if (shear) { + normalize_v3(cov); + normalize_v3(cou); + + /* Why is scale_cross called `cross` when we call `dot`? The next line calculates: + * `scale_cross += length(cross(cross(cou, face_normal), cov))` + * By construction, both `cou` and `cov` are orthogonal to the face normal. + * By definition, the normal vector has unit length. */ + scale_cross += dot_v3v3(cou, cov) * weight; + } + weight_sum += weight; + } + if (scale_cou * scale_cov < 1e-10f) { + break; + } + const float scale_factor_u = scale_uv ? sqrtf(scale_cou / scale_cov) : 1.0f; + + /* Compute correction transform. */ + float t[2][2]; + t[0][0] = scale_factor_u; + t[1][0] = clamp_f((float)(scale_cross / weight_sum), -0.5f, 0.5f); + t[0][1] = 0; + t[1][1] = 1.0f / scale_factor_u; + + /* Apply the correction. */ + p_chart_uv_transform(chart, t); + + /* How far from the identity transform are we? [[1,0],[0,1]] */ + const float err = fabsf(t[0][0] - 1.0f) + fabsf(t[1][0]) + fabsf(t[0][1]) + + fabsf(t[1][1] - 1.0f); + + const float tolerance = 1e-6f; /* Trade accuracy for performance. */ + if (err < tolerance) { + /* Too slow? Use Richardson Extrapolation to accelerate the convergence.*/ + break; + } + } + } + chart->u.pack.area = 0.0f; /* 3d area */ chart->u.pack.rescale = 0.0f; /* UV area, abusing rescale for tmp storage, oh well :/ */ @@ -4292,18 +4373,16 @@ void GEO_uv_parametrizer_average(ParamHandle *phandle, bool ignore_pinned) if (chart->u.pack.area != 0.0f && chart->u.pack.rescale != 0.0f) { fac = chart->u.pack.area / chart->u.pack.rescale; - /* Get the island center */ - p_chart_uv_bbox(chart, minv, maxv); - trans[0] = (minv[0] + maxv[0]) / -2.0f; - trans[1] = (minv[1] + maxv[1]) / -2.0f; - - /* Move center to 0,0 */ - p_chart_uv_translate(chart, trans); + /* Average scale. */ p_chart_uv_scale(chart, sqrtf(fac / tot_fac)); - /* Move to original center */ - trans[0] = -trans[0]; - trans[1] = -trans[1]; + /* Get the current island center. */ + p_chart_uv_bbox(chart, minv, maxv); + + /* Move to original center. */ + mid_v2_v2v2(trans, minv, maxv); + negate_v2(trans); + add_v2_v2(trans, chart->u.pack.origin); p_chart_uv_translate(chart, trans); } }