How To Get The Closest Point

[nick98]

I wander how to get the closest point on surface about a assign point use MEL.I know there is a node named closestPointOnsurface can do it ,but i need use MEL command.

[kurianos3d]

QUOTE(nick98 @ 04/24/06, 02:42 PM) [snapback]235195[/snapback]
I wander how to get the closest point on surface about a assign point use MEL.I know there is a node named closestPointOnsurface can do it ,but i need use MEL command.

Hi

Maya Bouns Tool you can get a plugin closestPointOnMesh.mll

thorugh that you can do it

[ewerybody]

there is also nearestPointOnMesh.mll delivered with Maya 7 isn't it?

I believe there are two modes you can use the command with:
1. create a nearestPointOnMesh/closestPointOnMesh-node and connect it with your stuff and get the values from the attribute plugs.
2. use it directly via mel with a specified mesh and query the values directly.

[joojaa]

there are many places in maya where a node is used as mel command by making it temporarily then querry and delete the node.

[ewerybody]

Nah more detailed I mean: first you can create such a node and connect the closest point with a locators translation-attributes so you can move the node and interactively see what happens where and when. Know what I mean? Sometimes useful for character rigs and stuff.

On the other hand you can just send the mel command and get the values you want without anything being visually created. You just query something.

Is that 2 ways enough? ;]

[joojaa]

Yes i understand whtat you say but in maya theres sometimes a understandable confusion on wether a command is:

A convininece creator/querryer/editr for a nodetype

A mel equalient of the node

or both

But thing is its allmost allways the first case, so even if it would seem logical form the command reference taht one could use the command to querry the stuff without the node, thats not true. Thats because many times the code operates on those nodes and those nodes alone. THuis having no internal logic to querry stuff. This baceuse the command is paired to the node but not a mel work command.

The 3 most OVIOUS alternative is rare indeed!

[bfx]

Reviving this old thread. It seems like creating a temporary node and sampling it is the way to go.

Here's a bit of python for returning either a list of nodes, or a list of uvVals

You will need a sample surface, an array of points, and a choice between uvVals or nodes.

Select your sample surface and assign it with 'sampleSurface = cmd.ls(sl=True)[0]'

Supply an array of points to sample. Select the objects - locators or whatever, and run this:

points = []
for i in cmd.ls(sl=True):
point = cmd.xform(i, q = True, t = True, ws = True)
points.append(point)

Here is the function to return either values or nodes, depending on what you need

import maya.cmds as cmd
import maya.mel as mel
gA = cmd.getAttr
sA = cmd.setAttr
cA = cmd.connectAttr
cN = cmd.createNode
def getClosestPointsOnSurface(points, sampleSurface, type = 'nodes'):
returnVal = None
cposNodes = []
vals = []
split = sampleSurface.split('_')
surf = cmd.listRelatives(sampleSurface, c = True, ni = True, type = 'nurbsSurface')[0]
if type == 'nodes':
for i in range(len(points)):
cPos = cN('closestPointOnSurface', ss = True, n = '%s_%02d_cPos' % (split[0], i))
cA('%s.worldSpace[0]' % surf, '%s.inputSurface' % cPos)
sA('%s.inPosition' % cPos, points[i][0], points[i][1], points[i][2])
cposNodes.append(cPos)
returnVal = cposNodes
if type == 'vals':
for i in range(len(points)):
cPos = cN('closestPointOnSurface', ss = True)
cA('%s.worldSpace[0]' % surf, '%s.inputSurface' % cPos)
sA('%s.inPosition' % cPos, points[i][0], points[i][1], points[i][2])
u = gA('%s.result.parameterU' % cPos )
v = gA('%s.result.parameterV' % cPos )
vals.append([u,v])
cmd.delete(cPos)
returnVal = vals
return returnVal

Finally, the example command to run

cposNodes = getClosestPointsOnSurface(points, sampleSurface, type = 'nodes')
uvVal = getClosestPointsOnSurface(points, sampleSurface, type = 'vals')

sampleSurface
Result: u'face_def_surf'

points
Result: [[-9.934378258772887e-05, 56.52158927169142, 13.096842334001089],
[-1.2986319080810456, 56.573714757526794, 13.019487214074514],
[-2.3988572845724603, 56.81671021609732, 12.825554268688125],
[-2.887766742811174, 57.28272070017139, 12.744081627653983],
[-2.9564472997142497, 57.50138883790414, 12.769442914295668],
[-2.879458555286166, 57.672685482014, 12.879225548927492],
[-2.192046597368875, 57.79139587725608, 13.341300849584687],
[-1.140138085103556, 57.811148683446966, 13.800117232849214],
[-0.0007878168005395606, 57.81488077210223, 13.925655903295926],
[1.1383058170299245, 57.81117323292432, 13.796743621692903],
[2.191000144083259, 57.79144462951285, 13.339583497622566],
[2.879303203717313, 57.67272400054267, 12.878886599401458],
[2.9563649858235075, 57.50140832665556, 12.769194174384452],
[2.887671243257571, 57.282744486066534, 12.743798227096866],
[2.398733183100953, 56.81673428803417, 12.825116354417371],
[1.2984150038822726, 56.57377235530355, 13.018506756780637]]

uvVal
Result: [[1.0004341542613102, 0.2301692487434747],
[1.2064782285634066, 0.21627448891449497],
[1.3722637684008845, 0.28391258246162415],
[1.509186903505303, 0.3387848920830241],
[1.563309727886676, 0.36916657892685023],
[1.6002270473405233, 0.369506881916711],
[1.6601835924689776, 0.24208844308577132],
[1.7978056591853022, 0.10984749089757448],
[1.9998468370341644, 0.10376750763367472],
[0.20215057952270601, 0.10949474728688213],
[0.33988142055839465, 0.24195245274626373],
[0.39978054787266903, 0.3695019564741386],
[0.4366984973876268, 0.3691695706042126],
[0.4908336188623674, 0.3387896663238795],
[0.6277812551226932, 0.2839743883775245],
[0.7935635789475637, 0.21646212421961572]] #

cposNodes
Result: [u'face_00_cPos',
u'face_01_cPos',
u'face_02_cPos',
u'face_03_cPos',
u'face_04_cPos',
u'face_05_cPos',
u'face_06_cPos',
u'face_07_cPos',
u'face_08_cPos',
u'face_09_cPos',
u'face_10_cPos',
u'face_11_cPos',
u'face_12_cPos',
u'face_13_cPos',
u'face_14_cPos',
u'face_15_cPos'] #