Maya2020Python Can't get the number of mel.eval('uvTkDoGetTexelDensity')

[243202504]

I used Maya’s script editor to write the code, and I encountered a problem in it. I want to get the pixel density of my selected part. This function is available in Maya’s UV toolkit. Click the Get button as shown in the figure below. Get a number in the back box, but I don't know how to get this number through code. Including me, I can't get the 512 after the Map Size below.

The code I use is

mel.eval('uvTkDoGetTexelDensity')

当我打印它，我得到没有。也许此功能不会返回值，但会将获得的值给 UI 界面后面的框。

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我使用的代码是

mel.eval('uvTkDoGetTexelDensity')

打印打印可能这个功能没有返回值，而是把得到的值给了UI界面后面的方框里。

[243202504]

There are errors in the Chinese part above, just read English.

[243202504]

When I print its value, I get None. Maybe this function will not return a return value, but will give the obtained value to the UI box later. I need your help and tell me how to get the average pixel density calculated in the box below.

[zewt · Accepted solution]

uvTkDoGetTexelDensity is a callback for updating a UI field, it doesn't return a value.  It just takes the texture size and calls texGetTexelDensity:

map_size = cmds.optionVar('polyUVTexelDensityMapSize', q=True)

density = mel.eval('texGetTexelDensity(%i)' % map_size)

map_size is the texture size set in the options box.  The polyUVTexelDensityMapSize optionVar won't exist if the user hasn't used that options box before.  texGetTexelDensity will also raise an error if there's no object selected to query density for.

[243202504]

Thanks for ur reply!

"map_size is the texture size set in the options box. The polyUVTexelDensityMapSize optionVar won't exist if the user hasn't used that options box before."

I don't know how to set texture size, I give a number in 'Map Size:' box (512). script editor raise 'uvTkTexelDensityChangeCB', and then I run 

import maya.cmds as cmds
 
map_size = cmds.optionVar('polyUVTexelDensityMapSize', q=True)
print map_size

it raise 

# Error: Object polyUVTexelDensityMapSize is invalid
# Traceback (most recent call last):
#   File "<maya console>", line 3, in <module>
# TypeError: Object polyUVTexelDensityMapSize is invalid # 

[243202504]

ok i found a way ,

map_size = cmds.optionVar(q='polyUVTexelDensityMapSize')

and then i got print 512.

[zewt]

FYI, that's just the last-used setting in the options box (and it won't exist if that options box has never been used).

[243202504]

yeah,and i create a value,then it will be created.

i use it at my code first line like this

# coding=utf-8
import maya.cmds as cmds
from maya import mel
from functools import wraps

map_size = cmds.optionVar(q='polyUVTexelDensityMapSize')

and then it will be created.

[243202504]

btw,i have a new quesion now,,, i can query the value of map_size,but i found,optionVar is undoable, queryable, and NOT editable. so if i want change the valuse of ui box, set size as 512 or 1024 ,how can i do ,what commnd should i use? ty!

[243202504]

texCalculateTexelDensity

density = mel.eval('texGetTexelDensity(%i)' % map_size)

This line of code takes too long. Is there any other way? If I get the vertices of the face, the UV ratio and the texture size to calculate the accuracy, or if I don’t need to call mel, but directly use python to speed it up. This Lines of code take up more than 90% of the time consumed by my entire tool. I want to optimize it.