Ogre 13 User Survey Results

During the period of Jan 10. – February 10. we received 54 replies. At the same time the ogre 13.2.4 Windows SDK alone was downloaded 2188 times. So while the results are insightful, they are probably not representative.

When it comes to RenderSystems, we finally see a significant drop for the legacy systems (D3D9, GL). This will allow us to focus on new features only supported on modern APIs. However, I doubt the numbers for Vulkan, given how recent the Vulkan addition was.

The most relevant result for further development is likely the question of target audience. Here, we see an increase of the enthusiast portion at the cost of the Enterprise one. I take it as we can sacrifice some API stability to gain modern rendering techniques when moving forward.

The following one is also interesting, as the HLMS was dropped with Ogre 13 and the inclusion in the poll is a copy/ paste error. I guess that any component with less than 18 votes is not actually used, but people were merely ticking every option.

As always statistics are lies though, so better take a look at the actual numbers yourself.

Specific replies

Following the #MeanTweets idea I also wrote some short replies to the criticism, that you can read below:

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Ogre 13.3 released

Ogre 13.3.0 was just released. This release contains some significant feature additions, which we will discuss in more detail below.

For a full overview of the changes, see the changelog.

PBR Material support

The most significant addition is probably built-in PBR support via the RTSS.

To enable the PBR pipeline via material scripts, specify

rtshader_system
{
   lighting_stage metal_roughness texture Default_metalRoughness.jpg
}

The parameters are expected to be in the green and blue channels (as per glTF2.0) and lighting will be done according to the Filament equations.
Alternatively, you can use material-wide settings, by omitting the texture part like:

rtshader_system
{
   lighting_stage metal_roughness
}

Here, metalness is read from specular[0] and roughness from specular[1].

Furthermore, the Assimp Plugin will automatically use the PBR pipeline, if it encounters any PBR maps. This in turn allows correctly loading and displaying glTF2 meshes – as shown in the ogre-meshviewer screenshot above.

Improved Gamepad Support

The Gamepad Support in OgreBites (via SDL2) has been improved. Now the according events are correctly delegated to ImGui, so you can control the UI with your gamepad.

Also additional gamepad mappings can be specified by placing a gamecontroller.txt in the working directory.

Ogre 13 User Survey 2022

Those of you who have been around Ogre for some time might remember that back in 2020, we conducted a survey about our user base. The results of which can be found here.

For the Ogre 13 development cycle we would like to assess to correctly emphasize the development on the most used features.

So for the next four weeks until the 10th of February, you have the chance to participate and help us to get an impression about our user base, how Ogre is used and share some wishes for the future. Simply follow the link and make your way through the 14 questions. It should not take up much time since most of the questions are simple checkbox or radio button questions.

We want to thank you all upfront for helping us to develop Ogre further and getting some valuable insight information about the people using the engine!

PS: We would be glad if you could spread the word about the survey via all available channels to all potential Ogre users, because: The more participants, the more accurate are the results of course.

Ogre 13.2 released

Ogre 13.2.0 was just released. This “holiday release” contains mostly bugfixes, however there are also some notable additions.

Vulkan RenderSystem

The elephant in the Room is likely the addition of the Vulkan Rendersystem – as was announced earlier. Contrary to my expectation, progress was quite smooth though. This means that all basic features are already in place and the RTSS and Terrain Components support Vulkan too. Therefore, the Vulkan RenderSystem is now tagged [BETA] instead of [EXPERIMENTAL]. Still, some more advanced features are currently missing.

Fresnel Sample Running on Vulkan

Depending on your usage, you might be able to already port your application – at least you can already start familiarizing with it. There are two caveats though..

Buffer updates

Currently Ogre does not try to hide the asynchronicity of Vulkan from the user and rather lets you run into rendering glitches.
The general idea of Vulkan is that you have multiple images in flight to keep the GPU busy. This means that we submit the work for the next frame without waiting for the current frame to finish.
This part hits you as soon as try to update vertex data. If the GPU is not yet done processing it, you will get rendering glitches. Particularly, your rendering will be broken if you update the data each frame.
The solution here is to either implement triple-buffering yourself or discard the buffer contents on update, which will give you new memory on Vulkan. The Ogre internals have been updated accordingly and ideally also improve performance on all other rendersystems.

Rendering interruption

Closely related to the above is rendering interruption. This means that after the first Renderable was submitted for the current frame (i.e. RenderSystem::_render has been called), you decide to load another Texture or update a buffer.

As we dont know whether the update affects the current Frame, we would need to interrupt the rendering, do the upload and continue where we left off. While certainly possible, we just throw an exception right now. Typically, it is much easier to just schedule your buffer updates before rendering kicks off, than ordering things mid-flight. And this is faster too.

Using GLSLang with GL3+

As the RTSS was extended to generate SPIRV compatible GLSL for Vulkan, it was natural to enable this path for GL3+ as well. If the gl_spirv profile is supported, you can now call

mShaderGenerator->setTargetLanguage("glslang");

to use the glslang reference compiler instead of whatever your GL driver would do.

HiDPi support in Overlays

Some dangling threads in Overlays were fixed and you can now call

Ogre::OverlayManager::getSingleton().setPixelRatio(appContext.getDisplayDPI()/96);

which will scale up the UI appropriately and generate higher resolution Fonts. The magic 96 means 96 DPI which is the common setting of all Monitors up to FullHD.

Depth of Field Sample

I have updated the dormant DoF compositor code we had in Ogre to actually do something.

The sample builds upon the code of DWORD flying around the forums and implements the following technique by Thorsten Scheuermann.

The Depth of Field compositor in action

Vulkan RenderSystem in Ogre 13

The Vulkan RenderSystem backport from Ogre-next, now has landed in the master branch and will be available with Ogre 13.2. See the screenshot below for the SampleBrowser running on Vulkan

The code was simplified during backporting, which shows by the size reduction from ~33k loc in Ogre-Next to ~9k loc that are now in Ogre.

The current implementation pretends to have Fixed Function capabilities, which allows operating with one default shader – similarly to what I did for Metal. This shader only supports using a single 2D texture without lighting. E.g. vertex color is not supported. This is why the text is white instead of black in the screenshot above.
Nevertheless, it already runs on Linux, Windows and Android.

Proper lighting and texturing support, will require some adaptations to the GLSL writer in the RTSS, as Vulkan GLSL is slightly different to OpenGL GLSL. This, and the other currently missing features will hopefully come together during the 13.x development cycle. If you are particularly keen on using Vulkan, consider giving a hand.
Right now, the main goal is to get Vulkan feature-complete first, so dont expect it to outperform any of the other RenderSystems. Due to being incomplete, the Vulkan RenderSystem is tagged EXPERIMENTAL.