The 1.12.6 point release kept its focus on integration. Notably, it ships the Qt OgreBites implementation, that was discussed in the previous post. Also there are the following notable changes:
The OSX & iOS support was vastly improved. If you had any issues with using Ogre in these enviroments, please try again with Ogre 1.12.6. The improvements include scaling the input events along the window content scaling and corrected library resolution from inside an .app bundle. I also started backporting the Metal RenderSystem to the 1.x series. See the metal-wip branch. Help is welcome.
Also Ogre 1.12 is now available in Debian sid & unstable. Notably, this also covers the python bindings and imgui. So prototyping a 3D application is only a apt install python3-ogre-1.12 away. Also this is a major step forward from the previous Ogre 1.9 package and allows 3rd party apps like ROS relying on it. These packges are also availble in the latest Ubuntu 20.04 release, which is based off Debian unstable.
Next, the MSVC SDK was refined: it now properly packages and compiles the C# ibindings. You no longer have to compile any Ogre C# sources yourself. As for C++, the pdb files are finally included, which allows you using the SDK for debugging (note that the build type still is RelWithDebInfo and not Debug).
The refined “Fixed Pipeline Enabled” RenderSystem option allows you to bring the legacy GL & D3D9 RenderSystems into a programmable pipeline only mode. Setting it to false is the first step, if you consider porting to GL3+ & D3D11 as it will enable the RTSS shader generation, while keeping everything else the same. It also allows you toggling forth and back between shader based and fixed pipeline to compare rendering, instead of having to pull the plug once and for all.
Probably the biggest strength of Ogre 1.x is the legacy of content creation tools and addons. Here, I resurrected the following tools beneath the OGRECave umbrella:
The meshmagick CLI .mesh optimization and manipulation tool. It allows you to conveniently change the coordinate system or merge all sub-meshes into one buffer.
The shiny shader meta-compiler & management library. In the mid-term we want to extend the RTSS by similar features and generally recommend to prefer the RTSS. However, there are some existing projects relying on this library, and this allows them to upgrade to recent Ogre releases.
The ogre-gpgpu toolkit. This is a collection of many Computer Vision and Augmented Reality related tools built around Ogre. So far, I only brought back the Ogre-CUDA bridge. When it is ready, this probably will be moved into the core repository. Therefore, this project can be considered as a staging area.
While there have been snippets to provide Ogre integration with Qt for a long time, there is now an officially provided version in master and scheduled for Ogre 1.12.6.
This integration requires Qt5 and builds upon the ApplicationContext abstraction living in OgreBites which already handles SDL2 windowing and Activities on Android. In contrast to previous attempts this means that it does not follow the “QtOgreWidget approach”. This might sound less convenient, but is necessary to properly handle multiple Ogre Windows or Ogre Views. Also it should be familiar for everybody who is using the QApplication API.
The implementation lives in a separate libOgreBitesQt.so library which is only created when Qt is detected when building – so if you do not use it, you do not have to care about Qt dependencies.
The API is designed to be a drop-in replacement for ApplicationContext. This means that you can just take the setup tutorial, but use the ApplicationContextQt instead and your app will be Qt5 based. Also, because of the Input event abstraction we did for Ogre 1.11.0, the CameraMan and Trays code will continue working – just like the Event forwarding to ImGui.
Furthermore, I have ensured that the API also fits when the Qt Event loop is used and adapts to existing projects. For this, I have ported ogitor and spacescape to the new API. Notably, with spacescape the Ogre view is now only redrawn on-demand when things change (e.g. settings, window resize).
The exposed API is QWindow based making it lightweight as only the QtGui module is required. Also this should allow extending it for QtQuick in the future, which is also QWindow based.
During the period of Feb 29. – March 31. we received 47 replies. At the same time the ogre 1.12.5 Windows SDK alone was downloaded 437 times. So while the results are significant, they are probably not representative.
The most interesting result is probably this
When considering the boosted votes of the patreon supporters, the enterprise and enthusiasts parts increase. Still, the enterprise fraction remains dominant.
Those of you who have been around Ogre for some time might remember that back in 2018, we conducted a survey about our user base. The results of which can be found here.
For the 1.13 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 29th of March, 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 13 questions. It should not take up much time since most of the questions are simple checkbox or radio button questions.
OGRE scripts offer a way to define materials at an abstraction level similar to D3D Effects and CgFX where you can define alternative techniques, each consisting of one or multiple passes. Here, each pass defines a render pipeline state by defining blend modes and referencing shaders. The main difference in OGRE is that you cannot write inline shaders in the script file as we support different render systems with different shading languages.
Traditionally, OGRE allows to use fixed function pipeline (FFP) functionality where you do not have to write any shaders, as long as Phong shading and a fixed set of texture operations is enough for your use case.
However, modern Render Systems like D3D11 or GL3 no longer include FFP parts to reflect that modern hardware does not either and is rather based on unified programmable SIMT pipelines.
To abstract form this difference, OGRE therefore offers the Real Time Shader System (RTSS) component, that generates shaders that seamlessly replace the absent FFP functionality. In most cases OGRE is able to produce pixel-perfect results.
However, as the RTSS generates shaders internally, you can customize the rendering in much more detail then was possible with the FFP. Here, you do not have to write your own shaders but can keep the high abstraction that OGRE scripts offer and just use the rtshader_system section to declare the features you want. Still this, gives you a large amount of control how things are rendered.
The most simple thing to do is enabling per pixel lighting (which is default in 1.12 anyway) or make the shading respect the physical energy conservation rule as described here.
However, the RTSS also enables you to create complex custom render pipelines via OGRE scripts as it offers the following features (the emphasized parts require OGRE 1.12.5)
Depth texture shadows
Below are some examples how this might look like:
The first screenshot shows the instancing sample, where the RTSS extended the vertex shader to read from the instance buffer as well as the fragment shader to apply depth based shadows. If you switch to the PF_DEPTH format for the depth texture, it will automatically use hardware PCF as it does not incur any performance penalty.
The second screenshot shows integrated offset mapping with multiple lights. As this is handled by the RTSS as well, it can be combined with hardware skinning and instancing – all you need is to add a single line in your material. No need to touch any shader code, while being compatible to all supported render systems.
See the respective Samples on how to integrate this in your own projects.
Deprecation of the HLMS backport
If you are familiar with OGRE, you probably also know that there is the High Level Material System Component in OGRE1. Actually this Component is a backport of the respective core element of OGRE-next (2.1+), where it handles shader variations and thus has a similar goal of the RTSS.
However, it got only little love in OGRE1 after the initial backport, so even as of today there is no way to use it form OGRE scripts. Also I am not aware of any users, as there was not a single bug-report regarding the HLMS. To reflect that the RTSS is in all cases the preferred alternative, the HLMS is therefore deprecated in OGRE1 and will be removed with the next release, if nobody steps up to object.