extrudesurf and s2m about iso2mesh HOT 4 CLOSED

hi @praveenvenky, it would be a lot easier for me to understand the problem if you can attach some sample images or script/data.

generally speaking, after meshcheckrepair, you will unlikely to get the same number of nodes/element because the repairing is performed independently on both the top/bottom surfaces.

from iso2mesh.

hi @fangq , please see the below script
My problem is to get the bottom part with same number of nodes and elements as Top part.
But without using meshcheckrepair i cannot get the result to s2m.
Also, if I use meshcheckrepair, it gives different number of elements as you said.
Is there a possibility for me to get same number of elements?

%%
load('elements_TP.mat'); % elements of top part

load('nodes_TP.mat') % nodes of TP

%% Extract all the triangular faces of top part.
[openface,elemid]=volface(elements_TP(:,2:5));
openface(:,4) = elemid;
node=nodes_TP(:,2:4)
% surfExt_Top(openface, node)
%% Extracting the neg-Z surface of the top part
% here I have used normals to take only the bottom elements and nodes of TP.
% then I have to extrude it dowwnwards to get the bottom part.
t=4.5;
extrude_vector=[0 0 -t];
keepratio= 1;
maxvol=15;
ISO2MESH_TETGENOPT='-A -q1.1a'
[Neg_zface,node,Neg_z_node_numbers,Neg_z_node_coords] = negZ_top(openface, nodes_TP(:,2:4));% node_coords=nodes_TP(:,2:4)

difference= Neg_z_node_numbers-find(Neg_z_node_numbers)
triangularelements=Neg_zface;
% these below 5 lines are just to get uniform numbering of node and not to bother much abt it
for i=1:length(Neg_zface)
triangularelements(i,1)=Neg_zface(i,1) - difference(Neg_z_node_numbers(:,1)==Neg_zface(i,1));
triangularelements(i,2)=Neg_zface(i,2) - difference(Neg_z_node_numbers(:,1)==Neg_zface(i,2));
triangularelements(i,3)=Neg_zface(i,3) - difference(Neg_z_node_numbers(:,1)==Neg_zface(i,3));
end
plotmesh(Neg_z_node_coords,triangularelements)
%% Giving offset value as a parametric value(for cohesive layer)
offset= 0.3;
Neg_z_node_coords(:,3)=Neg_z_node_coords(:,3)-offset;

%%
[extrude_node,extrude_face] = extrudesurf(Neg_z_node_coords,triangularelements,extrude_vector);
[extrude_node,extrude_elem]=meshcheckrepair(extrude_node,extrude_face,'meshfix');
plotmesh(extrude_node,extrude_elem)
[bottom_part_nodes,bottom_part_elem,bottom_part_faces] = s2m(extrude_node,extrude_elem,keepratio,maxvol);
plotmesh(bottom_part_nodes,bottom_part_elem)

node=bottom_part_nodes;
elem=bottom_part_elem;

from iso2mesh.

@praveenvenky, unfortunately meshcheckrepair (more specifically, meshfix) does not have the capability to correlate two surface patches.

the only way to do this is perhaps recreating the bottom (or top part) from the other part by projecting one to another (or projecting to a plane). It is going to be complicated.

from iso2mesh.

from iso2mesh.