From da93da45eefd2288f6bdb5ff18fa46f3e80cac75 Mon Sep 17 00:00:00 2001 From: Campbell Barton Date: Wed, 4 Nov 2020 00:01:19 +1100 Subject: Docs: add comments to some surface deform internal structures --- .../blender/modifiers/intern/MOD_surfacedeform.c | 60 +++++++++++++++++----- 1 file changed, 46 insertions(+), 14 deletions(-) (limited to 'source/blender/modifiers/intern/MOD_surfacedeform.c') diff --git a/source/blender/modifiers/intern/MOD_surfacedeform.c b/source/blender/modifiers/intern/MOD_surfacedeform.c index e19056d302f..1a79ed79461 100644 --- a/source/blender/modifiers/intern/MOD_surfacedeform.c +++ b/source/blender/modifiers/intern/MOD_surfacedeform.c @@ -70,6 +70,9 @@ typedef struct SDefAdjacencyArray { uint num; /* Careful, this is twice the number of polygons (avoids an extra loop) */ } SDefAdjacencyArray; +/** + * Polygons per edge (only 2, any more will exit calculation). + */ typedef struct SDefEdgePolys { uint polys[2], num; } SDefEdgePolys; @@ -83,37 +86,67 @@ typedef struct SDefBindCalcData { const MPoly *const mpoly; const MEdge *const medge; const MLoop *const mloop; + /** Coordinates to bind to, transformed into local space (compatible with `vertexCos`). */ float (*const targetCos)[3]; + /** Coordinates to bind (reference to the modifiers input argument). */ float (*const vertexCos)[3]; float imat[4][4]; const float falloff; int success; } SDefBindCalcData; +/** + * This represents the relationship between a point (a source coordinate) + * and the face-corner it's being bound to (from the target mesh). + * + * \note Some of these values could be de-duplicated however these are only + * needed once when running bind, so optimizing this structure isn't a priority. + */ typedef struct SDefBindPoly { + /** Coordinates copied directly from the modifiers inptut. */ float (*coords)[3]; + /** Coordinates projected into 2D space using `normal`. */ float (*coords_v2)[2]; + /** The point being queried projected into 2D space using `normal`. */ float point_v2[2]; float weight_angular; float weight_dist_proj; float weight_dist; float weight; float scales[2]; + /** Center of `coords` */ float centroid[3]; + /** Center of `coords_v2` */ float centroid_v2[2]; + /** + * The calculated normal of coords (could be shared between faces). + */ float normal[3]; float cent_edgemid_vecs_v2[2][2]; + /** + * The unsigned angle of this face-corner in `[0.0 .. PI]` range, + * where a small value is a thin corner. PI is is a straight line. + * Take care dividing by this value as it can approach zero. + */ float edgemid_angle; float point_edgemid_angles[2]; float corner_edgemid_angles[2]; float dominant_angle_weight; + /** Index of the input polygon. */ uint index; + /** Number of vertices in this face. */ uint numverts; + /** + * This polygons loop-start. + * \note that we could look this up from the polygon. + */ uint loopstart; uint edge_inds[2]; uint edge_vert_inds[2]; + /** The index of this corner in the face (starting at zero). */ uint corner_ind; uint dominant_edge; + /** When true `point_v2` is inside `coords_v2`. */ bool inside; } SDefBindPoly; @@ -256,7 +289,7 @@ static int buildAdjacencyMap(const MPoly *poly, { const MLoop *loop; - /* Fing polygons adjacent to edges */ + /* Find polygons adjacent to edges. */ for (int i = 0; i < numpoly; i++, poly++) { loop = &mloop[poly->loopstart]; @@ -466,7 +499,7 @@ BLI_INLINE SDefBindWeightData *computeBindWeights(SDefBindCalcData *const data, bwdata->bind_polys = bpoly; /* Loop over all adjacent edges, - * and build the SDefBindPoly data for each poly adjacent to those. */ + * and build the #SDefBindPoly data for each poly adjacent to those. */ for (vedge = vert_edges; vedge; vedge = vedge->next) { uint edge_ind = vedge->index; @@ -475,7 +508,7 @@ BLI_INLINE SDefBindWeightData *computeBindWeights(SDefBindCalcData *const data, bpoly = bwdata->bind_polys; for (int j = 0; j < bwdata->numpoly; bpoly++, j++) { - /* If coords isn't allocated, we have reached the first uninitialized bpoly */ + /* If coords isn't allocated, we have reached the first uninitialized `bpoly`. */ if ((bpoly->index == edge_polys[edge_ind].polys[i]) || (!bpoly->coords)) { break; } @@ -530,7 +563,7 @@ BLI_INLINE SDefBindWeightData *computeBindWeights(SDefBindCalcData *const data, } } - /* Compute poly's parametric data */ + /* Compute polygons parametric data. */ mid_v3_v3_array(bpoly->centroid, bpoly->coords, poly->totloop); normal_poly_v3(bpoly->normal, bpoly->coords, poly->totloop); @@ -540,7 +573,7 @@ BLI_INLINE SDefBindWeightData *computeBindWeights(SDefBindCalcData *const data, cross_v3_v3v3(axis, bpoly->normal, world); normalize_v3(axis); - /* Map coords onto 2d normal plane */ + /* Map coords onto 2d normal plane. */ map_to_plane_axis_angle_v2_v3v3fl(bpoly->point_v2, point_co, axis, angle); zero_v2(bpoly->centroid_v2); @@ -595,7 +628,7 @@ BLI_INLINE SDefBindWeightData *computeBindWeights(SDefBindCalcData *const data, bpoly->corner_edgemid_angles[1] = angle_normalized_v2v2(tmp_vec_v2, bpoly->cent_edgemid_vecs_v2[1]); - /* Check for inifnite weights, and compute angular data otherwise */ + /* Check for infinite weights, and compute angular data otherwise. */ if (bpoly->weight_dist < FLT_EPSILON) { inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_DIST_PROJ; inf_weight_flags |= MOD_SDEF_INFINITE_WEIGHT_DIST; @@ -665,10 +698,10 @@ BLI_INLINE SDefBindWeightData *computeBindWeights(SDefBindCalcData *const data, } } - /* Compute scalings and falloff. - * Scale all weights if no infinite weight is found, - * scale only unprojected weight if projected weight is infinite, - * scale none if both are infinite. */ + /* Compute scaling and falloff: + * - Scale all weights if no infinite weight is found. + * - Scale only un-projected weight if projected weight is infinite. + * - Scale none if both are infinite. */ if (!inf_weight_flags) { bpoly = bwdata->bind_polys; @@ -892,7 +925,7 @@ static void bindVert(void *__restrict userdata, interp_weights_poly_v2( sdbind->vert_weights, bpoly->coords_v2, bpoly->numverts, bpoly->point_v2); - /* Reproject vert based on weights and original poly verts, + /* Re-project vert based on weights and original poly verts, * to reintroduce poly non-planarity */ zero_v3(point_co_proj); for (int j = 0; j < bpoly->numverts; j++, loop++) { @@ -1290,9 +1323,8 @@ static void surfacedeformModifier_do(ModifierData *md, return; } - /* Early out if modifier would not affect input at all - still *after* the sanity checks (and - * potential binding) above. - */ + /* Early out if modifier would not affect input at all - still *after* the sanity checks + * (and potential binding) above. */ if (smd->strength == 0.0f) { return; } -- cgit v1.2.3