# Enable opacity mapping for surfaces using a different array than for color mapping
**URL:** https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646
**Category:** Feature Requests
**Created:** [July 19, 2021, 5:01pm UTC](https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646 "2021-07-19T17:01:02Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@bievreg](https://discourse.paraview.org/u/bievreg)
#### Post date: [July 19, 2021, 5:01pm UTC](https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646/1 "2021-07-19T17:01:02Z")
Hi Paraview team and many thanks for this awesome software.
I use vtk files containing several arrays.
I really would love a feature that would allow to map the opacity of surface rendering using a different array than the one used for coloring the surface (with arrays contained in the same vtk file).
Thanks in advance,
greg
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [August 3, 2021, 8:34am UTC](https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646/2 "2021-08-03T08:34:25Z")
Not supported by the surface mapper sadly.
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### Author:  [@wascott](https://discourse.paraview.org/u/wascott)
#### Post date: [August 3, 2021, 4:12pm UTC](https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646/3 "2021-08-03T16:12:44Z")
@cory.quammen @utkarsh.ayachit @Kenneth_Moreland @mwestphal Thoughts? How hard would this be, and how useful would it be?
I’m on the fence. Seems like a useful feature, but I have never had a user ask for it…
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### Author:  [@cory.quammen](https://discourse.paraview.org/u/cory.quammen)
#### Post date: [August 3, 2021, 6:29pm UTC](https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646/4 "2021-08-03T18:29:32Z")
We support this in the volume rendering. I don’t think it would be too hard to support for surface data.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [August 4, 2021, 7:17am UTC](https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646/5 "2021-08-04T07:17:17Z")
I definitely agree.
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### Author:  [@bievreg](https://discourse.paraview.org/u/bievreg)
#### Post date: [August 5, 2021, 9:21am UTC](https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646/6 "2021-08-05T09:21:35Z")
Dear all,
Thanks for your answers. To illustrate a little bit, it can be used e.g. in geophysics. For instance, we retrieve the spatial distribution of physical parameters undeground. This imaging is achieved using inversion, which encompasses error/uncertainty. This error can be represented by opacity blending superimposed to the array of the geophysical parameter of interest.
Below is an example of an electical resistivity image (2D distribution of resistivity) with an opacity mapping using the error/uncertainty (the lower the opacity the higher the uncertainty, and vice-versa).
Regards,
Greg
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### Author:  [@wascott](https://discourse.paraview.org/u/wascott)
#### Post date: [October 7, 2021, 10:31pm UTC](https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646/7 "2021-10-07T22:31:48Z")
[https://gitlab.kitware.com/paraview/paraview/-/issues/21015](https://gitlab.kitware.com/paraview/paraview/-/issues/21015). Sandia picked this one up. Scheduled for 5.11.
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### Author:  [@louisgag](https://discourse.paraview.org/u/louisgag)
#### Post date: [November 16, 2022, 2:12pm UTC](https://discourse.paraview.org/t/enable-opacity-mapping-for-surfaces-using-a-different-array-than-for-color-mapping/7646/8 "2022-11-16T14:12:56Z")
would it be hard to achieve this with the python console in the meantime?