Issues on disabling map scalars

Tao_Tian · August 8, 2025, 12:56am

I was trying to open a 3D image of which the suffix is .tif in paraview.

The original image is in RGB color, however paraview automatically applied color mapping on my image, that is, my image is changed to a scalar image with only 1 number per pixel, instead of 3 per pixel.

I checked paraview tutorial. It tells me to disable “MapScalar” in “Display” section, but I was unable to find it. I also checked FAQs in this forum but the answers are dated.

Could anyone tell me how to disable Mapscalar via the user interface, so that my tif image is presented in RGB color?

I also noticed that there is something called pvpython, is it feasible to disable Mapscalar via pvpython? Or maybe is there any other solutions?

Thank you very much.

Best regards,

P.S. I am a new user of paraview, so could you also kindly tell me how to run pvpython in paraview, if your solution include anything that relates to pypthon?

mwestphal · August 8, 2025, 8:38am

Tao_Tian · August 11, 2025, 2:23am

Thank you for your response!

While I did successfully disable map scalars by opening the advanced settings, there was an error shown in “Output Messages” tab saying “the data must have either 2 or 4 components”.

So I checked further about map scalars, and I found this section on paraview tutorial

The tutorial said data array can be deemed as color if it is an unsigned char with 3 components.

However my data, while satisfying this condition, still triggers an error. My data is an unsigned char containing 3 components ranging from 0 to 255.

Does this means to disable map scaler needs an RGBA format image, that is, should a column of data containing the opacity of each pixel be added? Or is there other ways to navigate through this problem?

Thank you again for your patient response!

Best regards,

mwestphal · August 25, 2025, 8:39am

Please share your data