fixes scale on derivative maps
[blender.git] / source / blender / blenkernel / intern / DerivedMesh.c
index 4b91911a6ab6f17b3b41c63a815f0837ef4a17ca..c829d840ace121eb7c393f38a9777fef0fc8cd6c 100644 (file)
@@ -184,6 +184,7 @@ void DM_init(DerivedMesh *dm, DerivedMeshType type,
        DM_init_funcs(dm);
        
        dm->needsFree = 1;
+       dm->auto_bump_scale = -1.0f;
 }
 
 void DM_from_template(DerivedMesh *dm, DerivedMesh *source, DerivedMeshType type,
@@ -1831,6 +1832,159 @@ void DM_add_tangent_layer(DerivedMesh *dm)
        MEM_freeN(vtangents);
 }
 
+void DM_calc_auto_bump_scale(DerivedMesh *dm)
+{
+       int totvert= dm->getNumVerts(dm);
+       int totface= dm->getNumFaces(dm);
+
+       MVert * mvert = dm->getVertArray(dm);
+       MFace * mface = dm->getFaceArray(dm);
+       MTFace * mtface = dm->getFaceDataArray(dm, CD_MTFACE);
+
+       if(mtface)
+       {
+               double dsum = 0.0;
+               int nr_accumulated = 0;
+               int f;
+
+               for ( f=0; f<totface; f++ )
+               {
+                       {
+                               float * verts[4], * tex_coords[4];
+                               const int nr_verts = mface[f].v4!=0 ? 4 : 3;
+                               int i, is_degenerate;
+
+                               verts[0]=mvert[mface[f].v1].co; verts[1]=mvert[mface[f].v2].co; verts[2]=mvert[mface[f].v3].co;
+                               tex_coords[0]=mtface[f].uv[0]; tex_coords[1]=mtface[f].uv[1]; tex_coords[2]=mtface[f].uv[2];
+                               if(nr_verts==4)
+                               {
+                                       verts[3]=mvert[mface[f].v4].co;
+                                       tex_coords[3]=mtface[f].uv[3];
+                               }
+
+                               // discard degenerate faces
+                               is_degenerate = 0;
+                               if(     equals_v3v3(verts[0], verts[1]) || equals_v3v3(verts[0], verts[2]) || equals_v3v3(verts[1], verts[2]) ||
+                                       equals_v2v2(tex_coords[0], tex_coords[1]) || equals_v2v2(tex_coords[0], tex_coords[2]) || equals_v2v2(tex_coords[1], tex_coords[2]) )
+                               {
+                                       is_degenerate = 1;
+                               }
+
+                               // verify last vertex as well if this is a quad
+                               if ( is_degenerate==0 && nr_verts==4 )
+                               {
+                                       if(     equals_v3v3(verts[3], verts[0]) || equals_v3v3(verts[3], verts[1]) || equals_v3v3(verts[3], verts[2]) ||
+                                               equals_v2v2(tex_coords[3], tex_coords[0]) || equals_v2v2(tex_coords[3], tex_coords[1]) || equals_v2v2(tex_coords[3], tex_coords[2]) )
+                                       {
+                                               is_degenerate = 1;
+                                       }
+
+                                       // verify the winding is consistent
+                                       if ( is_degenerate==0 )
+                                       {
+                                               float prev_edge[2];
+                                               int is_signed = 0;
+                                               sub_v2_v2v2(prev_edge, tex_coords[0], tex_coords[3]);
+
+                                               i = 0;
+                                               while ( is_degenerate==0 && i<4 )
+                                               {
+                                                       float cur_edge[2], signed_area;
+                                                       sub_v2_v2v2(cur_edge, tex_coords[(i+1)&0x3], tex_coords[i]);
+                                                       signed_area = prev_edge[0]*cur_edge[1] - prev_edge[1]*cur_edge[0];
+                                                       if ( i==0 ) is_signed = signed_area<0.0f ? 1 : 0;
+                                                       else if((is_signed!=0)!=(signed_area<0.0f)) is_degenerate=1;
+
+                                                       if ( is_degenerate==0 )
+                                                       {
+                                                               copy_v2_v2(prev_edge, cur_edge);
+                                                               ++i;
+                                                       }
+                                               }
+                                       }
+                               }
+
+                               // proceed if not a degenerate face
+                               if ( is_degenerate==0 )
+                               {
+                                       int nr_tris_to_pile=0;
+                                       // quads split at shortest diagonal
+                                       int offs = 0;           // initial triangulation is 0,1,2 and 0, 2, 3
+                                       if ( nr_verts==4 )
+                                       {
+                                               float pos_len_diag0, pos_len_diag1;
+                                               float vtmp[3];
+                                               sub_v3_v3v3(vtmp, verts[2], verts[0]);
+                                               pos_len_diag0 = dot_v3v3(vtmp, vtmp);
+                                               sub_v3_v3v3(vtmp, verts[3], verts[1]);
+                                               pos_len_diag1 = dot_v3v3(vtmp, vtmp);
+
+                                               if(pos_len_diag1<pos_len_diag0)
+                                                       offs=1;         // alter split
+                                               else if(pos_len_diag0==pos_len_diag1)           // do UV check instead
+                                               {
+                                                       float tex_len_diag0, tex_len_diag1;
+
+                                                       sub_v2_v2v2(vtmp, tex_coords[2], tex_coords[0]);
+                                                       tex_len_diag0 = dot_v2v2(vtmp, vtmp);
+                                                       sub_v2_v2v2(vtmp, tex_coords[3], tex_coords[1]);
+                                                       tex_len_diag1 = dot_v2v2(vtmp, vtmp);
+
+                                                       if(tex_len_diag1<tex_len_diag0)
+                                                       {
+                                                               offs=1;         // alter split
+                                                       }
+                                               }
+                                       }
+                                       nr_tris_to_pile = nr_verts-2 ;
+                                       if ( nr_tris_to_pile==1 || nr_tris_to_pile==2 )
+                                       {
+                                               const int indices[] = {offs+0, offs+1, offs+2, offs+0, offs+2, (offs+3)&0x3 };
+                                               int t;
+                                               for ( t=0; t<nr_tris_to_pile; t++ )
+                                               {
+                                                       float f2x_area_uv;
+                                                       float * p0 = verts[indices[t*3+0]];
+                                                       float * p1 = verts[indices[t*3+1]];
+                                                       float * p2 = verts[indices[t*3+2]];
+
+                                                       float edge_t0[2], edge_t1[2];
+                                                       sub_v2_v2v2(edge_t0, tex_coords[indices[t*3+1]], tex_coords[indices[t*3+0]]);
+                                                       sub_v2_v2v2(edge_t1, tex_coords[indices[t*3+2]], tex_coords[indices[t*3+0]]);
+
+                                                       f2x_area_uv = fabsf(edge_t0[0]*edge_t1[1] - edge_t0[1]*edge_t1[0]);
+                                                       if ( f2x_area_uv>FLT_EPSILON )
+                                                       {
+                                                               float norm[3], v0[3], v1[3], f2x_surf_area, fsurf_ratio;
+                                                               sub_v3_v3v3(v0, p1, p0);
+                                                               sub_v3_v3v3(v1, p2, p0);
+                                                               cross_v3_v3v3(norm, v0, v1);
+
+                                                               f2x_surf_area = len_v3(norm);
+                                                               fsurf_ratio = f2x_surf_area/f2x_area_uv;        // tri area divided by texture area
+
+                                                               ++nr_accumulated;
+                                                               dsum += (double)(fsurf_ratio);
+                                                       }
+                                               }
+                                       }
+                               }
+                       }
+               }
+
+               // finalize
+               {
+                       const float avg_area_ratio = (nr_accumulated>0) ? ((float)(dsum / nr_accumulated)) : 1.0f;
+                       const float use_as_render_bump_scale = sqrtf(avg_area_ratio);           // use width of average surface ratio as your bump scale
+                       dm->auto_bump_scale = use_as_render_bump_scale;
+               }
+       }
+       else
+       {
+               dm->auto_bump_scale = 1.0f;
+       }
+}
+
 void DM_vertex_attributes_from_gpu(DerivedMesh *dm, GPUVertexAttribs *gattribs, DMVertexAttribs *attribs)
 {
        CustomData *vdata, *fdata, *tfdata = NULL;
@@ -1851,6 +2005,10 @@ void DM_vertex_attributes_from_gpu(DerivedMesh *dm, GPUVertexAttribs *gattribs,
        else
                tfdata = fdata;
 
+       /* calc auto bump scale if necessary */
+       if(dm->auto_bump_scale<=0.0f)
+               DM_calc_auto_bump_scale(dm);
+
        /* add a tangent layer if necessary */
        for(b = 0; b < gattribs->totlayer; b++)
                if(gattribs->layer[b].type == CD_TANGENT)