What can cause cutMesh to fail without throwing an error?

[ParvGuptaSpCT]

Hello Devs!!

I'm trying to solve a problem where I need to cut a mesh using a specific contour, but the cutMesh method I'm using seems to be failing silently. I'm not getting any error messages or exceptions.

Goal:

1. Project the given point onto the mesh
2. Create OneMeshContour using convertMeshTriPointsToClosedContour
3. Cut mesh using cutMesh

Problem:
when i run the cutMesh method the code fails silently without any error message or exception making things difficult to debug.

I have tried repairing the mesh, which works in some scenarios but not in other scenarios. for reference I am adding the code snippet below with the required mesh and points.

In what scenarios could a cutMesh method fail silently without providing an error message? and how to tackle this situation.

Find mesh here

Scenario 1:
After mesh healing the code works fine (the issue is away from the actual cut area)
points:

[[16.646656036376953, 14.741708755493164, 4.576032638549805], [16.668277740478516, 14.384010314941406, 4.569797039031982], [16.576833724975586, 14.013505935668945, 4.631280422210693], [16.512680053710938, 13.777043342590332, 4.761350631713867], [16.393449783325195, 13.403670310974121, 5.002175331115723], [16.269216537475586, 13.182912826538086, 4.984068393707275], [16.20830726623535, 12.923381805419922, 5.087211608886719], [16.019271850585938, 12.61654281616211, 5.124899387359619], [15.901768684387207, 12.393928527832031, 5.141350269317627], [15.599367141723633, 11.991620063781738, 5.186203479766846], [15.346027374267578, 11.856232643127441, 5.133361339569092], [15.122776985168457, 11.587782859802246, 5.2799072265625], [14.896747589111328, 11.457191467285156, 5.27760124206543], [14.44242000579834, 11.33584213256836, 5.210615158081055], [14.158003807067871, 11.27537727355957, 5.127418041229248], [13.927963256835938, 11.212697982788086, 5.050159454345703], [13.550372123718262, 11.25624942779541, 4.744230270385742], [13.25623607635498, 11.328841209411621, 4.522640228271484], [12.962186813354492, 11.36681079864502, 4.429788589477539], [12.50127124786377, 11.442442893981934, 4.305820465087891], [12.213642120361328, 11.457968711853027, 4.231110095977783], [11.85752010345459, 11.512750625610352, 4.144808769226074], [11.600076675415039, 11.559830665588379, 4.079421520233154], [11.380637168884277, 11.627155303955078, 4.075072765350342], [11.2041015625, 11.732147216796875, 4.11557674407959], [10.953338623046875, 11.926736831665039, 4.119207382202148], [10.775550842285156, 12.123125076293945, 4.145244598388672], [10.579399108886719, 12.36453628540039, 4.070829391479492], [10.366140365600586, 12.652528762817383, 3.969512462615967], [10.104594230651855, 12.992469787597656, 3.762610673904419], [9.880121231079102, 13.277572631835938, 3.82735538482666], [9.755463600158691, 13.438217163085938, 3.615600347518921], [9.634434700012207, 13.586525917053223, 3.772613525390625], [9.578688621520996, 13.792163848876953, 3.745853900909424], [9.63358211517334, 13.962160110473633, 3.622021198272705], [9.598461151123047, 14.14792251586914, 3.712815284729004], [9.445578575134277, 14.692630767822266, 3.8106796741485596], [9.386147499084473, 15.038148880004883, 3.856213331222534], [9.358999252319336, 15.272607803344727, 3.9425511360168457], [9.373270988464355, 15.49432373046875, 4.096502780914307], [9.44054126739502, 15.750584602355957, 4.26950740814209], [9.570919036865234, 15.946880340576172, 4.508244514465332], [9.695297241210938, 16.18453598022461, 4.819686412811279], [9.756144523620605, 16.374073028564453, 5.021803379058838], [9.932418823242188, 16.649078369140625, 5.459493637084961], [10.06308650970459, 16.870826721191406, 5.846014976501465], [10.133369445800781, 17.05019187927246, 6.168216705322266], [10.200089454650879, 17.13922119140625, 6.3963189125061035], [10.443766593933105, 17.394046783447266, 6.872269630432129], [10.489845275878906, 17.576988220214844, 7.130134582519531], [10.669710159301758, 17.64646339416504, 7.41057825088501], [10.847245216369629, 17.73883819580078, 7.574862003326416], [11.175477981567383, 18.049556732177734, 7.834199905395508], [11.45338249206543, 18.18800163269043, 7.889533042907715], [11.785261154174805, 18.449399948120117, 7.917699813842773], [12.034139633178711, 18.77326774597168, 8.052335739135742], [12.46902847290039, 19.03756332397461, 8.006729125976562], [12.735586166381836, 19.1330509185791, 7.992079734802246], [13.232893943786621, 19.22369956970215, 7.839441299438477], [13.671405792236328, 19.314069747924805, 7.692601680755615], [13.939096450805664, 19.317180633544922, 7.387678623199463], [14.2461519241333, 19.32771873474121, 7.188783645629883], [14.346649169921875, 19.243146896362305, 6.962453365325928], [14.43930435180664, 19.180034637451172, 6.725870609283447], [14.55232048034668, 19.061174392700195, 6.513606548309326], [14.754919052124023, 18.869979858398438, 6.117575168609619], [14.958292007446289, 18.679901123046875, 5.797604084014893], [15.207849502563477, 18.439483642578125, 5.531602382659912], [15.463226318359375, 18.18120765686035, 5.2729573249816895], [15.619430541992188, 17.9746036529541, 5.166277885437012], [15.778491973876953, 17.73604965209961, 5.0684685707092285], [16.089250564575195, 17.377046585083008, 4.951489448547363], [16.20867156982422, 17.228174209594727, 4.959184646606445], [16.303564071655273, 17.053085327148438, 4.938669204711914], [16.370065689086914, 16.628320693969727, 4.809776306152344], [16.430513381958008, 16.300386428833008, 4.64534854888916], [16.4838924407959, 15.993921279907227, 4.746840000152588], [16.622291564941406, 15.490939140319824, 4.696885108947754], [16.645891189575195, 15.137458801269531, 4.693760871887207], [16.689334869384766, 15.014436721801758, 4.691181182861328]]

Scenario 2:
Healing mesh is not working
Points:

[[35.147891998291016, 28.379650115966797, 5.6943745613098145], [35.260223388671875, 28.608482360839844, 5.780847072601318], [35.21923828125, 28.88606071472168, 5.956310272216797], [35.265926361083984, 29.187097549438477, 6.062460899353027], [35.24356460571289, 29.457609176635742, 6.171724319458008], [35.31626510620117, 29.69383430480957, 6.302514553070068], [35.61784744262695, 30.089975357055664, 6.494657516479492], [35.75308609008789, 30.300029754638672, 6.656350135803223], [35.871707916259766, 30.545438766479492, 6.975792407989502], [36.033905029296875, 30.704544067382812, 7.204006671905518], [36.356292724609375, 30.985628128051758, 7.575130939483643], [36.82295608520508, 31.281980514526367, 7.857728004455566], [37.01785659790039, 31.35580825805664, 8.032557487487793], [37.363014221191406, 31.515214920043945, 8.354000091552734], [37.635677337646484, 31.534921646118164, 8.40932846069336], [37.889644622802734, 31.480178833007812, 8.281763076782227], [38.175262451171875, 31.517375946044922, 8.487613677978516], [38.43841552734375, 31.559642791748047, 8.566298484802246], [38.81558609008789, 31.516149520874023, 8.610889434814453], [39.22357177734375, 31.554771423339844, 8.725379943847656], [39.65693283081055, 31.54215431213379, 8.923067092895508], [39.91238784790039, 31.519271850585938, 9.05361557006836], [40.37059020996094, 31.455904006958008, 9.068062782287598], [40.62029266357422, 31.41095733642578, 9.137317657470703], [40.96510314941406, 31.39547348022461, 9.1502046585083], [41.23041534423828, 31.336715698242188, 9.143682479858398], [41.60706329345703, 31.265518188476562, 9.137439727783203], [41.70210647583008, 31.338903427124023, 8.899513244628906], [41.83659362792969, 31.44288444519043, 8.650862693786621], [42.02439498901367, 31.66779327392578, 8.214963912963867], [42.118831634521484, 31.754575729370117, 7.968873023986816], [42.243167877197266, 31.79886817932129, 7.655329704284668], [42.564735412597656, 31.72575569152832, 7.640833377838135], [42.82301712036133, 31.681766510009766, 7.427731037139893], [43.21234130859375, 31.60764503479004, 7.177220344543457], [43.48101806640625, 31.586164474487305, 6.773580551147461], [43.813377380371094, 31.4157657623291, 6.702082633972168], [44.04494857788086, 31.185501098632812, 6.613493919372559], [44.27897644042969, 30.960063934326172, 6.596883296966553], [44.52530288696289, 30.67266082763672, 6.723759651184082], [44.710296630859375, 30.438905715942383, 6.674567699432373], [44.91715621948242, 30.27840232849121, 6.154368877410889], [44.95042419433594, 30.02033805847168, 5.701589584350586], [45.17271041870117, 29.85580825805664, 5.983430862426758], [45.34718322753906, 29.568973541259766, 6.050870418548584], [45.443607330322266, 29.30426597595215, 6.020230770111084], [45.63146209716797, 28.953105926513672, 6.258945465087891], [45.74567413330078, 28.764724731445312, 6.412456512451172], [45.797515869140625, 28.3389949798584, 6.428510665893555], [45.982872009277344, 28.13019561767578, 6.237601280212402], [46.273380279541016, 27.827064514160156, 6.433323860168457], [46.42356491088867, 27.436357498168945, 6.326049327850342], [46.586524963378906, 27.128597259521484, 6.482540130615234], [46.78357696533203, 26.614822387695312, 6.754849433898926], [46.5179557800293, 26.317760467529297, 6.7746477127075195], [46.49858856201172, 26.057449340820312, 6.846417427062988], [46.565608978271484, 25.762353897094727, 6.828423976898193], [46.6419792175293, 25.438495635986328, 6.582269668579102], [46.59128189086914, 25.257427215576172, 6.358142375946045], [46.51280212402344, 25.133832931518555, 6.112646102905273], [46.412750244140625, 24.756567001342773, 5.850030899047852], [46.30047607421875, 24.495054244995117, 5.580385684967041], [46.111392974853516, 24.29238510131836, 5.326410293579102], [45.87942886352539, 24.103118896484375, 5.092268466949463], [45.61134338378906, 23.862579345703125, 4.884676456451416], [45.408782958984375, 23.567684173583984, 4.824876308441162], [45.262474060058594, 23.33175277709961, 4.777509689331055], [45.05574035644531, 23.04823875427246, 4.705463409423828], [44.80215835571289, 22.800689697265625, 4.627740383148193], [44.565216064453125, 22.621795654296875, 4.530584335327148], [44.36326217651367, 22.47791862487793, 4.474918842315674], [43.97602462768555, 22.178342819213867, 4.376025199890137], [43.4293327331543, 21.867626190185547, 4.316689968109131], [43.13663101196289, 21.831796646118164, 4.208077430725098], [42.72270965576172, 21.67452049255371, 4.12863826751709], [42.407569885253906, 21.56987190246582, 4.112375736236572], [42.161163330078125, 21.44312858581543, 4.184823513031006], [41.68114471435547, 21.382631301879883, 4.140745639801025], [41.39976501464844, 21.40509796142578, 4.078697681427002], [40.9514274597168, 21.3483943939209, 4.098167419433594], [40.60078430175781, 21.348697662353516, 4.109342575073242], [40.12710189819336, 21.526742935180664, 4.118013381958008], [39.783138275146484, 21.575061798095703, 4.181153774261475], [39.330387115478516, 21.84322166442871, 4.183180332183838], [38.86482620239258, 22.067794799804688, 4.23435115814209], [38.5469856262207, 22.27069091796875, 4.322722434997559], [38.30769348144531, 22.514354705810547, 4.342287540435791], [38.001346588134766, 22.74706268310547, 4.153634071350098], [37.98435592651367, 22.764022827148438, 4.159963607788086], [37.918670654296875, 22.829593658447266, 4.184433937072754], [37.85299301147461, 22.895160675048828, 4.208904266357422], [37.78944778442383, 22.992679595947266, 4.224210262298584], [37.73619079589844, 23.057661056518555, 4.2378926277160645], [37.67376708984375, 23.13129425048828, 4.259226322174072], [37.613319396972656, 23.201810836791992, 4.279483318328857], [37.54632568359375, 23.301544189453125, 4.283626556396484], [37.49256896972656, 23.388198852539062, 4.306225299835205], [37.442874908447266, 23.471363067626953, 4.326519966125488], [37.3922004699707, 23.555850982666016, 4.346835136413574], [37.34211730957031, 23.638858795166016, 4.3667707443237305], [37.29145050048828, 23.72243881225586, 4.387361526489258], [37.24085998535156, 23.806865692138672, 4.405511856079102], [37.19028091430664, 23.89051628112793, 4.426051616668701], [37.13969802856445, 23.974170684814453, 4.446591377258301], [37.0889892578125, 24.059532165527344, 4.467200756072998], [37.03911590576172, 24.14361000061035, 4.487903118133545], [36.98950958251953, 24.227142333984375, 4.507479190826416], [36.93875503540039, 24.312091827392578, 4.528470039367676], [36.889068603515625, 24.396461486816406, 4.5490617752075195], [36.839717864990234, 24.479520797729492, 4.571089744567871], [36.78953552246094, 24.56427764892578, 4.591963291168213], [36.739437103271484, 24.649869918823242, 4.612731456756592], [36.69049072265625, 24.734233856201172, 4.632213592529297], [36.64117431640625, 24.81863784790039, 4.653031826019287], [36.59185791015625, 24.903045654296875, 4.673852920532227], [36.542724609375, 24.98680305480957, 4.694864273071289], [36.49291229248047, 25.071693420410156, 4.715660095214844], [36.4436149597168, 25.156112670898438, 4.736481666564941], [36.39426040649414, 25.24029541015625, 4.7576003074646], [36.345420837402344, 25.324127197265625, 4.7775468826293945], [36.29560852050781, 25.4089412689209, 4.799206733703613], [36.24665069580078, 25.49110221862793, 4.821274757385254], [36.19688415527344, 25.574026107788086, 4.841944694519043], [36.14678192138672, 25.65669822692871, 4.862542629241943], [36.09574890136719, 25.74173355102539, 4.884191513061523], [36.04551696777344, 25.825721740722656, 4.904939651489258], [35.99518966674805, 25.909866333007812, 4.926119804382324], [35.945159912109375, 25.99384117126465, 4.946828842163086], [35.89513397216797, 26.077816009521484, 4.967538356781006], [35.84507369995117, 26.16152000427246, 4.988636493682861], [35.79494857788086, 26.245424270629883, 5.009631156921387], [35.74464416503906, 26.329959869384766, 5.030070781707764], [35.69355010986328, 26.416217803955078, 5.052435874938965], [35.64507293701172, 26.497028350830078, 5.074923038482666], [35.59498596191406, 26.581424713134766, 5.095579147338867], [35.545291900634766, 26.663331985473633, 5.120943069458008], [35.493873596191406, 26.74982452392578, 5.141292572021484], [35.44404220581055, 26.835111618041992, 5.164130687713623], [35.395320892333984, 26.918380737304688, 5.18536376953125], [35.346492767333984, 27.001827239990234, 5.20465087890625], [35.28406524658203, 27.14556312561035, 5.321690559387207], [35.25822830200195, 27.23788833618164, 5.3397674560546875], [35.23724365234375, 27.35265350341797, 5.372889518737793], [35.219818115234375, 27.44564437866211, 5.3873186111450195], [35.21764373779297, 27.582275390625, 5.421695709228516], [35.208152770996094, 27.650714874267578, 5.398820400238037], [35.20105743408203, 27.740615844726562, 5.415236949920654], [35.18647003173828, 27.823379516601562, 5.430356025695801], [35.168460845947266, 27.915355682373047, 5.4492950439453125], [35.15044403076172, 28.00733184814453, 5.468233108520508]]

Code snippet:

snappingPoints = list()
for pointData in circlePoints:
    point = mm.Vector3f(pointData[0], pointData[1], pointData[2])
    snappingPoints.append(mm.findProjection(point, mesh).mtp)

pathSearchSettings = mm.SearchPathSettings()
pathSearchSettings.geodesicPathApprox = mm.GeodesicPathApprox(1)
pathSearchSettings.maxReduceIters = 5

cutContours = list()
cutContours.append(
    mm.convertMeshTriPointsToClosedContour(mesh, snappingPoints, pathSearchSettings)
)

cutMesh = mm.cutMesh(mesh, cutContours)

components = list()
leftPart = mm.fillContourLeft(mesh.topology, cutMesh.resultCut)
components.append(leftPart)
rightPart = mesh.topology.getValidFaces() - leftPart
components.append(rightPart)

code reference: 3992

Thanks

[Grantim]

Hello!

It seems like a bug on our side, thanks for reporting, we will investigate and fix it, and get back to you

[Grantim]

The bug will be fixed with #5049. It will be available in next release, for now you can use such code:

def cutMeshSimple(mesh:mm.Mesh,circlePoints):
    points = mm.Contour3f()
    points.resize(int(len(circlePoints)/2)+1) # +1 to make it closed
    for i in range(int(len(circlePoints)/2)): 
        points[i] = mm.Vector3f(circlePoints[i*2][0],circlePoints[i*2][1],circlePoints[i*2][2]) # take each second point to avoid the bug
    points[len(points)-1] = points[0] # last equals first to indicate first
    return mm.cutMeshByContour(mesh,points)

components = list()
components.append(cutMeshSimple(inMesh, inPoints))
components.append(inMesh.topology.getValidFaces() - components[0])

• simplify general cutMesh usage
• use each second point of initial set to avoid the bug