# hardware accelerated headless rendering in version 6.0
**URL:** https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685
**Category:** ParaView Support
**Created:** [May 21, 2025, 9:08am UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685 "2025-05-21T09:08:12Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 9:08am UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/1 "2025-05-21T09:08:12Z")
We have ParaView-v6.0.0-RC1 compiled on a Grace Hopper cluster with the standard cmake options -DVTK\_OPENGL\_HAS\_EGL:BOOL=ON -DVTK\_USE\_X:BOOL=OFF
According to the release notes, the variable VTK\_DEFAULT\_OPENGL\_WINDOW can be used to force a specific backend
We set it to vtkEGLRenderWindow, and expects pvbatch to report the same output which we have with version v5.13 also compiled with the same options and the same compiler. Our baseline (v5.13) reports:
Vendor: NVIDIA Corporation
Version: 4.6.0 NVIDIA 550.54.15
Renderer: NVIDIA GH200 120GB/PCIe
whereas v6.0 reports:
Vendor: Mesa/X.org
Version: 3.3 (Core Profile) Mesa 22.3.5
Renderer: softpipe
our observation is that our distribution includes two different libEGL\*so version, namely, /usr/lib64/libEGL\_mesa.so, /usr/lib64/libEGL.so
and v6.0 seems to pick us the _mesa_ version, independently of our forcing it to use the NVIDIA version.
Are there tips on debugging this issue?
TIA
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [May 21, 2025, 9:37am UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/2 "2025-05-21T09:37:02Z")
I think the dynamic loading must find the libEGL\_mesa.so for some reason ?
What happens if you move it temporarly ?
FYI @jaswantp
---
### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 11:43am UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/3 "2025-05-21T11:43:14Z")
I cannot move it. This is a production system. I have no system rights.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [May 21, 2025, 11:46am UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/4 "2025-05-21T11:46:25Z")
does using LD\_PRELOAD has an effect ?
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### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 11:52am UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/5 "2025-05-21T11:52:50Z")
> [@mwestphal](#):
>
> LD\_PRELOAD
LD\_PRELOAD=/usr/lib64/libEGL.so ./bin/pvbatch -m paraview.info
OpenGL Vendor : Mesa/X.org
OpenGL Version : 3.3 (Core Profile) Mesa 22.3.5
OpenGL Renderer : softpipe
OpenGL Window Backend : OSMesa
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [May 21, 2025, 11:59am UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/6 "2025-05-21T11:59:54Z")
I’m out of ideas, but maybe @jaswantp will have another one.
In short we rely on `gladLoaderLoadEGL` to load the lib.
---
### Author:  [@jaswantp](https://discourse.paraview.org/u/jaswantp)
#### Post date: [May 21, 2025, 1:11pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/7 "2025-05-21T13:11:24Z")
> [@jfavre](#):
>
> and v6.0 seems to pick us the _mesa_ version, independently of our forcing it to use the NVIDIA version.
> [@mwestphal](#):
>
> I think the dynamic loading must find the libEGL\_mesa.so for some reason ?
Not possible, the EGL libraries that glad searches for [are](https://gitlab.kitware.com/vtk/vtk/-/blob/master/ThirdParty/glad/vtkglad/src/egl.c#L1140):
```c++
static const char *NAMES[] = {"libEGL.so.1", "libEGL.so"};
```
Moreover, `pvbatch -m paraview.info` printed “OpenGL Window Backend : OSMesa” so this is unlikely. In short, it used `vtkOSOpenGLRenderWindow` after realizing that `vtkEGLRenderWindow` failed to initialize.
@jfavre have you tried [`eglinfo`](https://github.com/dv1/eglinfo)?
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [May 21, 2025, 1:20pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/8 "2025-05-21T13:20:08Z")
> [@jaswantp](#):
>
> “OpenGL Window Backend : OSMesa”
I missed that.
---
### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 1:28pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/9 "2025-05-21T13:28:31Z")
there is no eglinfo installed on my system
I have tried
./bin/vtkProbeOpenGLVersion-pv6.0
2025-05-21 15:26:52.888 ( 0.020s) [FFFFA35AB370]vtkOpenGLRenderWindow.c:286 WARN| GL Message: id=1 source=SOURCE\_API(0x8246) type=ERROR(0x824c) severity=HIGH(0x9146) message=GL\_INVALID\_ENUM in glGetIntegerv(pname=GL\_MAX\_TESS\_GEN\_LEVEL)
Class: vtkOSOpenGLRenderWindow succeeded in finding a working OpenGL
OpenGL vendor string: Mesa/X.org
OpenGL renderer string: softpipe
OpenGL version string: 3.3 (Core Profile) Mesa 22.3.5
---
### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 1:30pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/10 "2025-05-21T13:30:38Z")
to compare with our v5.13 version:
./bin/vtkProbeOpenGLVersion-pv5.13
Class: vtkEGLRenderWindow succeeded in finding a working OpenGL
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: NVIDIA GH200 120GB/PCIe
OpenGL version string: 4.6.0 NVIDIA 550.54.15
---
### Author:  [@jaswantp](https://discourse.paraview.org/u/jaswantp)
#### Post date: [May 21, 2025, 1:36pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/11 "2025-05-21T13:36:58Z")
Can you try setting `VTK_DEFAULT_EGL_DEVICE_INDEX` to 1 or 2? It might be that it needs to try different device.
what happens if you did not set `VTK_DEFAULT_OPENGL_WINDOW` environment variable and just ran `./bin/vtkProbeOpenGLVersion-pv6.0`?
Btw, the default value for `VTK_OPENGL_HAS_EGL` is `ON` on UNIX platform.
---
### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 1:45pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/12 "2025-05-21T13:45:29Z")
I have 4 GPUs available, and can set VTK\_DEFAULT\_EGL\_DEVICE\_INDEX to 0,1,2 or 3 and the answer is always the same
the results is also independent of setting/unsetting `VTK_DEFAULT_OPENGL_WINDOW`
---
### Author:  [@jaswantp](https://discourse.paraview.org/u/jaswantp)
#### Post date: [May 21, 2025, 1:52pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/13 "2025-05-21T13:52:51Z")
Okay. It should atleast report some warnings if `vtkEGLRenderWindow` fails to find a device.
I expected to see atleast one of these warning messages:
1. from vtkEGLRenderWindow: "Getting the number of devices (graphics cards) on a system require "
“EGL\_EXT\_device\_base, EGL\_EXT\_platform\_device and EGL\_EXT\_platform\_base extensions”
2. from vtkEGLRenderWindow: “EGL device index: 0 could not be initialized. Trying other devices…”
3. from vtkEGLRenderWindow: “Could not initialize a device. Exiting…”
4. from vtkEGLRenderWindow: "Only EGL 1.4 and greater allows OpenGL as client API. "
“See eglBindAPI for more information.”
5. from vtkOpenGLRenderWindow: “Failed to initialize OpenGL functions!”
I’m surprised it doesn’t report a single warning besides that GL\_MAX\_TESS\_GEN\_LEVEL. This could only mean that `vtkEGLRenderWindow` was not compiled at all?
What are the contents of `$buildDir/VTK/Rendering/OpenGL2/vtkRenderingOpenGLConfigure.h`? This file also exists in the install directory. Does it have a `#define VTK_OPENGL_HAS_EGL`? Is there a `vtkEGLRenderWindow.cxx.o` object in your build dir?
---
### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 1:57pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/14 "2025-05-21T13:57:52Z")
more vtkRenderingOpenGLConfigure.h
// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
#ifndef vtkRenderingOpenGLConfigure\_h
#define vtkRenderingOpenGLConfigure\_h
/\* This header contains build settings for the vtkRenderingOpenGL2 module. _/
/_ It provides some compatibility with the vtkRenderingOpenGL module. \*/
#ifndef VTK\_OPENGL2
#define VTK\_OPENGL2
#endif
/\* Whether VTK was built to support Cocoa on the Mac. _/
/_ #undef VTK\_USE\_COCOA \*/
/_--------------------------------------------------------------------------_/
/\* Rendering Configuration _/
/_ #undef VTK\_USE\_X _/
#define VTK\_USE\_OPENGL\_LIBRARY
#define VTK\_OPENGL\_HAS\_EGL
/_ #undef VTK\_DEFAULT\_RENDER\_WINDOW\_OFFSCREEN _/
/_ #undef VTK\_OPENGL\_ENABLE\_STREAM\_ANNOTATIONS \*/
// for legacy codes (don’t use these in new codes)
#ifdef VTK\_DEFAULT\_RENDER\_WINDOW\_OFFSCREEN
# define VTK\_USE\_OFFSCREEN
#endif
/\* Options for GPUInfo _/
/_ #undef VTK\_USE\_DIRECTX _/
/_ #undef VTK\_USE\_CORE\_GRAPHICS _/
/_ #undef VTK\_USE\_NVCONTROL \*/
/_--------------------------------------------------------------------------_/
/\* Setup VTK based on platform features and configuration. \*/
/\* OGLR _/
/_ OGLR is for GLX. It can be on Unix, Mac or Windows \*/
#if ((defined(VTK\_USE\_OPENGL\_LIBRARY) && defined(VTK\_USE\_X) &&
!defined(\_WIN32)) ||
(defined(VTK\_USE\_X) && defined(\_WIN32))) &&
!defined(VTK\_USE\_COCOA)
# define VTK\_USE\_OGLR
#endif
#endif
find . -name vtkEGLRenderWindow.cxx.o
./CMakeFiles/RenderingOpenGL2.dir/vtkEGLRenderWindow.cxx.o
---
### Author:  [@jaswantp](https://discourse.paraview.org/u/jaswantp)
#### Post date: [May 21, 2025, 2:06pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/15 "2025-05-21T14:06:10Z")
Okay, thanks for sharing. That confirms its part of the build.
Is this a debug build? or a release build?
If it’s release, can you apply this patch in VTK subdir and rebuild?
```diff
diff --git a/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx b/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx
index 435d7d439a..aaf3f657bb 100644
--- a/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx
+++ b/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx
@@ -644,6 +644,7 @@ vtkOpenGLRenderWindow* vtkOpenGLRenderWindow::New()
#if defined(VTK_OPENGL_HAS_EGL)
if ((backend == nullptr) || (std::string(backend) == "vtkEGLRenderWindow"))
{
+ vtkLogF(INFO, "VTK_OPENGL_HAS_EGL is defined, trying gladLoaderLoadEGL");
// Load core egl functions.
if (!gladLoaderLoadEGL(EGL_NO_DISPLAY))
{
@@ -652,12 +653,17 @@ vtkOpenGLRenderWindow* vtkOpenGLRenderWindow::New()
}
else
{
+ vtkLogF(INFO, "gladLoaderLoadEGL succeeded");
vtkNew eglRenderWindow;
eglRenderWindow->Initialize();
if (eglRenderWindow->Initialized)
{
return eglRenderWindow->NewInstance();
}
+ else
+ {
+ vtkLogF(INFO, "eglRenderWindow->Initialize() failed, trying vtkOSOpenGLRenderWindow");
+ }
}
}
#endif
```
---
### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 2:59pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/16 "2025-05-21T14:59:28Z")
Did I misunderstand you? I have a Release build, but I don’t see any other log messages. Do I need an extra env variable?
[daint][jfavre@nid006325 ParaView-v6.0.0-RC1Build-EGL]$ ./bin/pvbatch -m paraview.info
ParaView Version : 6.0.0
VTK Version : 9.4.20250513
MPI Enabled : True
MPI Rank : 0
MPI Size : 1
Python Library Path : /user-environment/linux-sles15-neoverse\_v2/gcc-13.3.0/python-3.12.5-tiwaj3tabjlxhozzutmhoxawzy6pmm5s/lib/python3.12
Python Library Version : 3.12.5 (main, Jan 1 1980, 12:01:00) [GCC 13.3.0]
OpenGL Vendor : Mesa/X.org
OpenGL Version : 3.3 (Core Profile) Mesa 22.3.5
OpenGL Renderer : softpipe
OpenGL Window Backend : OSMesa
Disable Registry : False
HostName : nid006325
Client HostName : localhost
=====================================================
btw, I am not sure your paraview.info can be trusted at 100%. Here is why:
I did not enable MPI:
grep PARAVIEW\_USE\_MPI CMakeCache.txt
PARAVIEW\_USE\_MPI:BOOL=OFF
Yet, the paraview.info module reports “MPI Enabled : True” (see above)
---
### Author:  [@jaswantp](https://discourse.paraview.org/u/jaswantp)
#### Post date: [May 21, 2025, 3:05pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/17 "2025-05-21T15:05:04Z")
So the warnings should appear even on release builds. The reason I asked if it is a release build is because it’s easier to debug with print statements instead of stepping through in a debugger. Have you applied the patch I shared and rebuilt? Does it print the sentences in `vtkLog` from the patch file?
> [@jfavre](#):
>
> =====================================================
> btw, I am not sure your paraview.info can be trusted at 100%. Here is why:
> I did not enable MPI:
> grep PARAVIEW\_USE\_MPI CMakeCache.txt
> PARAVIEW\_USE\_MPI:BOOL=OFF
>
> Yet, the paraview.info module reports “MPI Enabled : True” (see above)
Very strange indeed!
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### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 4:35pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/18 "2025-05-21T16:35:03Z")
yes, I have applied the patch, and cannot get any log message printed.
I am making another build in Debug mode
---
### Author:  [@jaswantp](https://discourse.paraview.org/u/jaswantp)
#### Post date: [May 21, 2025, 4:38pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/19 "2025-05-21T16:38:07Z")
Okay. In debug mode, i would be interested if you can break at `vtkOpenGLRenderWindow::New` if it ever gets there that is.
---
### Author:  [@jfavre](https://discourse.paraview.org/u/jfavre)
#### Post date: [May 21, 2025, 5:16pm UTC](https://discourse.paraview.org/t/hardware-accelerated-headless-rendering-in-version-6-0/16685/20 "2025-05-21T17:16:04Z")
> [@jaswantp](#):
>
> vtkOpenGLRenderWindow::New
I am not getting there. I put a breakpoint in vtkOpenGLMessageHandler and this is how I got there:
199 std::string messageType;
Missing separate debuginfos, use: zypper install Mesa-libglapi0-debuginfo-22.3.5-150500.75.2.aarch64 libOSMesa8-debuginfo-22.3.5-150500.75.2.aarch64
(gdb) where
#0 vtkOpenGLMessageHandler (source=33350, type=33356, id=1, severity=37190,
message=0xffffffffb3e8 “GL\_INVALID\_ENUM in glGetIntegerv(pname=GL\_MAX\_TESS\_GEN\_LEVEL)”)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/VTK/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx:199
#1 0x0000ffffd32fcc1c in ?? () from /usr/lib64/libOSMesa.so.8
#2 0x0000ffffd348199c in ?? () from /usr/lib64/libOSMesa.so.8
#3 0x0000ffffd3483a9c in ?? () from /usr/lib64/libOSMesa.so.8
#4 0x0000ffffe9c4e4a8 in vtkOpenGLState::Initialize (this=0xa3ae50)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/VTK/Rendering/OpenGL2/vtkOpenGLState.cxx:1602
#5 0x0000ffffe9c0fffc in vtkOpenGLRenderWindow::OpenGLInitState (this=0xa3a270)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/VTK/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx:837
#6 0x0000ffffe9c0ffb0 in vtkOpenGLRenderWindow::OpenGLInit (this=0xa3a270)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/VTK/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx:825
#7 0x0000ffffe9c92f58 in vtkOSOpenGLRenderWindow::CreateOffScreenWindow (this=0xa3a270,
width=300, height=300)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/VTK/Rendering/OpenGL2/vtkOSOpenGLRenderWindow.cxx:322
#8 0x0000ffffe9c931b8 in vtkOSOpenGLRenderWindow::Initialize (this=0xa3a270)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/VTK/Rendering/OpenGL2/vtkOSOpenGLRenderWindow.cxx:393
#9 0x0000ffffe9c14ef0 in vtkOpenGLRenderWindow::Start (this=0xa3a270)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/VTK/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx:1913
#10 0x0000ffffe7c784d4 in vtkRenderWindow::Render (this=0xa3a270)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/VTK/Rendering/Core/vtkRenderWindow.cxx:450
#11 0x0000ffffe9c18ae4 in vtkOpenGLRenderWindow::Render (this=0xa3a270)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/VTK/Rendering/OpenGL2/vtkOpenGLRenderWindow.cxx:3064
#12 0x0000fffff01ea540 in vtkPVOpenGLInformation::CopyFromObject (this=0xa3a0e0, obj=0x0)
at /capstor/scratch/cscs/jfavre/ParaView/ParaView-v6.0.0-RC1/Remoting/Views/vtkPVOpenGLInformation.cxx:55
is discourse still the best way to communicate about this issue? feel free to engage in discussion with me in another channel.
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