Hello,
I am new to Mathematica. I trying do a interactive application.
I need to move some points with mouse, update them positions and draw them and update the position of another points that depend by them.
I have problem with my function drawSystemReference that should draw some arrows at the update coordinate positions.
I post the full code of my application.
(* create vertex list *)
CreatePointList := (
ph1 = Table[{t, 0}, {t, 0, 1,
0.1}]; (* (0,0) -> (1,
0) *)
ph2 = Table[{1, t}, {t, 0, 0.3,
0.1}]; (* (1,0) -> (1,
0.3) *)
ph3 = Table[{1 - t, 0.3}, {t, 0, 1,
0.1}]; (* (1,0.3) -> (0,0.3) *)
ph4 = Table[{0, 0.3 - t}, {t, 0, 0.3,
0.1}]; (* (0,0.3) -> (0,0) *)
l = Join[ph1, ph2, ph3, ph4]; l)
listVertex = CreatePointList;
(* create bones list initial position *)
listBonesRest = {{0.1, 0.15}, {0.35, 0.15}, {0.65, 0.15}, {0.9, 0.15} }
(* create bones list *)
listBones = {{0.1, 0.15}, {0.35, 0.15}, {0.65, 0.15}, {0.9, 0.15} }
(* matrici identità world space per i bones *)
matrix1 = {{1, 0}, {0, 1}};
lmatrixBones = {matrix1, matrix1, matrix1, matrix1};
NearPoint[list_, mpos_ ] :=
Nearest[list -> Range[Length[list]],
mpos]; (* trova l'indice del punto della lista list piu' vicino a \
mpos *)
(* trova gli indici dei k elementi della lista piu' vicini *)
NearestK[list_, k_, pos_] :=
Nearest[list -> Range[Length[list]], pos, k];
CreateVertexAttribute[listV_, listB_, k_] := Module[{l = {}},
Do[
x = listV[[i]];
nearP = NearestK[listB, k, x];
sumDist = 0;
Table[
sumDist += Norm[ x - listB[ [ nearP[[j]] ]] ], {j, 1,
Length[nearP]}];
l = Append[l,
Table[{nearP[[j]],
Norm[ x - listB[ [ nearP[[j]] ]] ]/sumDist}, {j, 1,
Length[nearP]} ]],
{i, 1, Length[listV]}
]; l];
vGraph = CreateVertexAttribute[listVertex, listBones, 2];
Attributes[calculateNewVertexPositions] = {HoldAll};
calculateNewVertexPositions[listV_, listB_, listBRest_, graph_] :=
Module[{l = {}},
Do[
x = listV[[i]];
vpos = {0, 0};
Table[wi := graph[[i, j, 2]] ; ibone := graph[[i, j, 1]];
vpos += wi*x - listBRest[[ibone]] + listB[[ibone]], {j, 1,
Length[ graph[[i]] ]}];
l = Append[l, vpos],
{i, 1, Length[listV]}
]; l];
Attributes[drawSystemReference] = {HoldAll};
drawSystemReference[listDerivedPos_, listMatrix_] := (
Table[ {
Arrow[ { listDerivedPos[[i]],
listDerivedPos[[i]] + listMatrix[[i]].{0.1, 0} } ] ,
Arrow[ { listDerivedPos[[i]],
listDerivedPos[[i]] +
listMatrix[[i]].{0.0, 0.1} } ] }, {i, 1,
Length[listDerivedPos]}]);
(* this is ok, I draw the reference system *)
Graphics[drawSystemReference[listBones, lmatrixBones]]
(* it's a wrong result... *)
Graphics[drawSystemReference[Dynamic[listBones],
Dynamic[lmatrixBones]]]
Attributes[updatePointList] = {HoldFirst};
updatePointList[list_, mpos_] := (index = NearPoint[list, mpos][[1]];
list[[index]] =
mpos) (* aggiorna l'elemento della lista piu' vicino a mpos con \
mpos *)
(* my main program *)
drawNode[pt_] := ({PointSize[Large], Point[pt]});
DynamicModule[{ lv = listVertex, lvr = listVertex, lb = listBones,
lbr = listBonesRest, vg = vGraph, lmb = lmatrixBones},
Graphics[{EventHandler[{drawSystemReference[Dynamic[lb],
Dynamic[lmb]], drawNode[Dynamic[lb]], PointSize[Large], Red,
Point[Dynamic[lv]],
Line[Dynamic[lv]]}, ImageSize -> Large,
"MouseClicked" :> (updatePointList[lb, MousePosition["Graphics"]]),
"MouseDragged" :> (updatePointList[lb, MousePosition["Graphics"]];
lv = calculateNewVertexPositions[lvr, lb, lbr, vg])]}]]
I have problem with the function drawSystemReference. if I run this command in Mathematica
Graphics[drawSystemReference[listBones, lmatrixBones]]
I get the expected result, while if I run this command
Graphics[drawSystemReference[Dynamic[listBones], Dynamic[lmatrixBones]]]
I did not understand
why I get a different result. I would like call drawSystemReference every time the listBones and lmatrixBones are changed. How can do it?
Thanks in advance.
Daniel.
