Hello, thanks for the reply.
I'll show you a simple example of the Python code I'm currently writing.
```
from maya.api import OpenMaya
DIRECTION_VEC = [OpenMaya.MFloatVector(0, 1, 0), OpenMaya.MFloatVector(0,
-1, 0), OpenMaya.MFloatVector(1, 0, 0), OpenMaya.MFloatVector(-1, 0, 0)]
mesh = "pCube1" # Deformed
selectionList = OpenMaya.MGlobal.getSelectionListByName(mesh)
mDagPath = selectionList.getDagPath(0)
meshFn = OpenMaya.MFnMesh(mDagPath)
def isIntersectPoints(meshFn, point):
sourcePt = OpenMaya.MFloatPoint(list(point))
for directionVec in DIRECTION_VEC:
if not meshFn.anyIntersection(sourcePt, directionVec,
OpenMaya.MSpace.kWorld, 9999, False):
return False;
return True
idsList = []
index = 0
for point in positions: # positions e.g) [(0, 0, 0), (0.5, 0.5, 0.5) ... ]
count : 10,000
if isIntersectPoints(meshFn, point):
idsList.append(index)
index += 1
```
Thank you.
2022년 9월 23일 금요일 오후 3시 50분 3초 UTC+9에 Marcus Ottosson님이 작성:
> Hello! I can shed some light on these.
>
> I tried to work the Python Loop part with C++ MPxCommand, but I couldn’t
> find a way to return data by executing the Arguments in the form of
> Float3Array (Point Positions) and the corresponding command. (Return :
> IntArray)
>
> If you are certain that looping isn’t going to be fast enough in Python,
> which I don't doubt, then yes this is what I would do. You won’t be able to
> return data outside of simple types like integers, floats and strings. But
> what you can do is serialise the data into e.g. JSON and output a string,
> and then deserialise it from Python. This is what I normally do. At a
> certain point, deserialising can become a bottleneck, at which point you
> have a JSON deserialiser in PySide2 which may be faster.
>
> It is said that the part can be written in C++ using PyBind, but I know
> that the For Loop speed is limited due to the same GIL issue. Is there any
> way to solve it??
>
> This point was what prompted me to reply - don’t do it! :D
>
> Both MPxCommand and PyBind can work outside of any GIL - they are both
> called outside of Python - and while PyBind *can* return more complex
> types like vectors and even Python objects it is terribly inconvenient to
> work with in Maya. Because Maya - and Python in general - cannot reload or
> unload a binary Python module. Yes, you read that right. Once you import
> myBinaryModule you cannot unload it. At all. The only recourse is
> restarting Maya.
>
> Other than that, if that isn’t a problem, then PyBind is a good option for
> this. You can even pass a NumPy data structure, which would bypass Python
> even further and keep all data - especially heavy data - in C++ and be as
> fast as it can be.
>
> It seems that there is no way to increase the speed of the current Python
> Loop by raising the speed of the loop as much as possible.
>
> Hard to say without having an example. Loops in Python shouldn’t be a
> bottleneck in general; but it’s possible the repeated access to a Maya API
> class could. Are you able to share a small reproducible? Would be curious
> to see what the problem may be.
>
> Best,
> Marcus
>
> On Fri, 23 Sept 2022 at 07:20, daeseok chae <cds...@gmail.com> wrote:
>
>> Hello,
>>
>> I am writing a script that extracts a Point located in a mesh using
>> anyIntersection of MFnMesh.
>>
>> However, there are too many points, so the performance does not come out
>> while looping.
>>
>> So I'm trying to find another way, but it's not easy to find example code.
>> Here's the method I've tried:
>>
>> 1. I tried to work the Python Loop part with C++ MPxCommand, but I
>> couldn't find a way to return data by executing the Arguments in the form
>> of Float3Array (Point Positions) and the corresponding command. (Return :
>> IntArray)
>> 2. It is said that the part can be written in C++ using PyBind, but I
>> know that the For Loop speed is limited due to the same GIL issue. Is there
>> any way to solve it??
>> 3. It seems that there is no way to increase the speed of the current
>> Python Loop by raising the speed of the loop as much as possible.
>>
>> Loop Count : 1,000,0000 Under
>> anyIntersection: 4 Direction (Up, Left, Right, Down)
>>
>> thank you
>>
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>>
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