# cannot use log scale due to opengl texture problem
**URL:** https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848
**Category:** ParaView Support
**Created:** [November 5, 2018, 3:57pm UTC](https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848 "2018-11-05T15:57:26Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@bradley](https://discourse.paraview.org/u/bradley)
#### Post date: [November 5, 2018, 3:57pm UTC](https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848/1 "2018-11-05T15:57:26Z")
I am using Paraview 5.2.0 on Fedora 25 with an NVidia GT 440 graphics card. I want to do volume rendering. My data covers several orders of magnitude, so I need to use a log scale for the color map. However, when I click the checkbox for using a log scale, a warning window opens up, which contains essentially the same message that is echoed to the terminal window:
Warning: In /builddir/build/BUILD/ParaView-v5.2.0/VTK/Rendering/VolumeOpenGL2/vtkOpenGLVolumeRGBTable.h, line 143
vtkObject (0x55b80a9ab090): This OpenGL implementation does not support the required texture size of 4194304, falling back to maximum allowed, 16384.This may cause an incorrect color table mapping.
Indeed, the color mapping doesn’t work, as changes I make to the color map aren’t reflected in the rendering.
Is this a graphics driver problem? I’m using the nouveau graphics driver that comes with Fedora rather than a native nvidia driver (according to nvidia, their own driver may not actually work as well as 3rd party drivers for this card!). Since changing the driver could mess up a lot of software that I use, I’d rather not risk changing it if it is not likely to be the source of the problem.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [October 23, 2019, 6:15am UTC](https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848/2 "2019-10-23T06:15:29Z")
> [@bradley](#):
>
> NVidia GT 440
Your GPU is quite old with only 1Gb of memory. You may want to use a CPU based solution for volume rendering. Switch the volume rendering mode to RayCast or OSPray.
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### Author:  [@Gwang-Jin\_Lee](https://discourse.paraview.org/u/Gwang-Jin_Lee)
#### Post date: [May 22, 2020, 1:54am UTC](https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848/3 "2020-05-22T01:54:12Z")
I am undergoing the same problem with 4 [NVIDIA Quadro GP100 GPU](http://images.nvidia.com/content/pdf/quadro/data-sheets/302049-NV-DS-Quadro-Pascal-GP100-US-NV-Fnl-WEB.pdf) 16GB:
> This OpenGL implementation does not support the required texture size of 1048576, falling back to maximum allowed, 32768.This may cause an incorrect color table mapping.
Is it related with the memory of GPU?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [May 22, 2020, 2:44am UTC](https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848/4 "2020-05-22T02:44:01Z")
Looks more like a driver issue here.
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### Author:  [@Gwang-Jin\_Lee](https://discourse.paraview.org/u/Gwang-Jin_Lee)
#### Post date: [May 25, 2020, 6:16pm UTC](https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848/5 "2020-05-25T18:16:17Z")
Dear Mathieu,
I attached my example which is resampled to image and it gives reproduction of the color mapping error:
1. Load the attached VTK.
2. Select variable ‘s’ with volume
3. Use the log scale
When I tested in my macbook pro, linux server(Quadro GP100) and windows desktop(GTX 1650), I got the same results.
Incorrect color table mapping occured.
Best regards,
Gwang-Jin
[Resample.vtk](https://discourse.paraview.org/uploads/short-url/j7PqDDx9HDxRhocPShR5ncSNZtN.vtk) (847.7 KB)
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [May 26, 2020, 1:44am UTC](https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848/6 "2020-05-26T01:44:45Z")
@martink : FYI
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### Author:  [@Gwang-Jin\_Lee](https://discourse.paraview.org/u/Gwang-Jin_Lee)
#### Post date: [June 3, 2020, 2:07am UTC](https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848/7 "2020-06-03T02:07:48Z")
When I used a linear scales with color transfer function values:
[1.0e-6, 2.0e-6, … , 1],
I got the same error message. Is there any workaround to solve the problem?
Thank you.
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### Author:  [@Gwang-Jin\_Lee](https://discourse.paraview.org/u/Gwang-Jin_Lee)
#### Post date: [January 19, 2021, 4:41am UTC](https://discourse.paraview.org/t/cannot-use-log-scale-due-to-opengl-texture-problem/848/8 "2021-01-19T04:41:45Z")
From Palas Kumar Farsoiya, I got to know a workaround to avoid the dark colormap.
This is changing the representation from volume to NVIDIA IndeX.
Thank Palas for informing.