Switch to GL3+ RenderSystem

[simonschmeisser]

This is WIP and based on #1725

• Find out why it does not find resources.cfg
• Find out how to decide which RenderSystem to use even though the GL version detection is part of the RenderSystem
• PointCloud shaders are plain white currently. Debug with RenderDoc

[simonschmeisser]

Sorry for bothering you once more @paroj, I tried enabling GL3+ rendering system but fail at early steps.

terminate called after throwing an instance of 'Ogre::InvalidStateException'
  what():  InvalidStateException: RenderSystem does not support FixedFunction, but technique of 'Grid0Material' has no Vertex Shader. Use the RTSS or write custom shaders. in SceneManager::_setPass at /home/sis/experimente/debian/ogre-1.12/OgreMain/src/OgreSceneManager.cpp (line 880)

I get this quite often and assume it's because I didn't setup the resource locations properly. I looked at how that is done normally and found this in OgreBites:
https://github.com/OGRECave/ogre/blob/4040a7988e94629bc1de66159b7eb57ddfeeb272/Components/Bites/src/OgreApplicationContextBase.cpp#L424

I think we just want to load the resources.cfg installed by the debian package in /usr/share/OGRE-VERSION/resources.cfg so I can either copy paste that function, get the location from CMake/pkgcfg or possibly create a OgreApplicationContextBase instance.

For simplicity I just copied the RTShaderSystem part and set the path manually for my version of ogre. Do I need to set the cache path? (Does not seem to make a difference and stays empty)

Do I need to change the material files?

[paroj]

you missed the listener
https://github.com/OGRECave/ogre/blob/4040a7988e94629bc1de66159b7eb57ddfeeb272/Components/Bites/src/OgreApplicationContextBase.cpp#L102

also see https://ogrecave.github.io/ogre/api/latest/rtss.html#rtssTech

[simonschmeisser]

Thanks @paroj, I made some little progress. The coordinate grid can now be displayed but other materials and shaders still crash:

terminate called after throwing an instance of 'Ogre::InvalidStateException'
  what():  InvalidStateException: RenderSystem does not support FixedFunction, but technique of 'robot link material' has no Vertex Shader. Use the RTSS or write custom shaders. in SceneManager::_setPass at /home/sis/experimente/debian/ogre-1.12/OgreMain/src/OgreSceneManager.cpp (line 880)

for our typical mesh display as well as for the picking shader ( https://github.com/ros-visualization/rviz/blob/noetic-devel/ogre_media/materials/scripts/default_pick_and_depth.material )

[paroj]

the RTSS will leave techniques that already have shaders alone. Some of your techniques merely have a fragment shader.

[rhaschke]

@simonschmeisser, what is the status of this PR. Obviously, your changes are not yet supported in default Ogre 1.9:

render_system.cpp:274:33: error: ‘RGN_INTERNAL’ is not a member of ‘Ogre’
    274 |                           Ogre::RGN_INTERNAL);

[simonschmeisser]

Well, that's just a string constant so it could be ifdefed or replaced by the actual string. My plan is to first get this to run well on ogre 1.12.13 or newer and then see how it can be made compatible with Ogre 1.9 or maybe enabled conditionally if that turns out not to be possible.

Next riddle to solve is why the RTSS thinks our default materials (for RobotModelDisplay eg) have a partial shader applied and then what VertexShader is required for the picking technique/material

[simonschmeisser]

terminate called after throwing an instance of 'Ogre::InvalidStateException'
  what():  InvalidStateException: RenderSystem does not support FixedFunction, but technique of 'robot link table_base:' has no Vertex Shader. Use the RTSS or write custom shaders. in SceneManager::_setPass at ./OgreMain/src/OgreSceneManager.cpp (line 844)

We have some entities where we create a Material from code without any material script. I tried following the advice in https://forums.ogre3d.org/viewtopic.php?t=96852 and added createShaderBasedTechnique but that does not seem to be sufficient?

[simonschmeisser]

I added a try-catch around ogre_root_->renderOneFrame(); and can now turn on and off plugins without rviz crashing. Interestingly MarkerArrayDisplay is working correctly. It seems to use the ogre default material:

rviz/src/rviz/default_plugin/markers/mesh_resource_marker.cpp

Line 145 in 68ce34b

if (material->getName() != "BaseWhiteNoLighting")