This work was possible because user Hotshot5000 took my branch, forked it, and advanced it further. The Vulkan port was a daunting, overwhelming task and his contributions greatly helped me figure out the way to make it work.
It also saved me a lot of time. Even though around 40% of his code couldn’t make it into the final version, it was still very important as a proof of concept or as a reference implementation to base from, or as a way to compare new non-working code against a working reference.
Existing applications may need to perform additional work to get Vulkan running (e.g. port shaders to Vulkan). While this isn’t difficult, there is no guide written yet.
The 2.3 preparations ticket has a list of things that have changed that may require a dev’s attention when porting from 2.2 to 2.3
This list is updated at irregular intervals; and once 2.3 is out this page is probably going to be moved somewhere else (in fact it is a draft for the News post whenever we release 2.3). But for the time being that ticket is our hub for checking 2.2 -> 2.3 changes.
Ogre 1.12.9 was just released. Typically we do not write a specific announcement for minor updates, however this one contains some major new features that warrant this one.
Multi Language GPU Programs
As noted in the last progress report, even when using OgreUnifiedShader.h one had to duplicate the GpuProgram definitions in the Ogre .material files. This has been fixed in master by allowing multi-language programs to be defined like
The separate ogre-assimp project was merged into the main repository as the Codec_Assimp Plugin, which allows loading arbitrary meshes and runtime and the OgreAssimpConverter Tool for converting meshes to the Ogre .mesh format offline (which improves loading time).
Especially the introduction of Codec_Assimp is notable, as mesh loading now goes through the same Codec dispatching as image formats.
On the application side, you can then just call sceneManager->createEntity("Bike.obj") like I did in OgreMeshViewer below:
so simply loading Codec_Assimp turned that into a general-purpose mesh-viewer.
Descriptive Hardware Buffer Usage
Did you ever wonder whether your buffer usage is rather static or rather dynamic? Well at least I did as these rather abstract names do not tell you much what it means in terms of memory allocation – but wonder no more! There are now new, actually descriptive, aliases:
New descriptive alias
So while previously you were told to use HBU_STATIC_WRITE_ONLY, you now immediately see that the buffer will end up in GPU memory. Likewise, if you use the DYNAMIC variant, the buffer will be optimized for recurrent CPU writes.
I came up with those when planning the Vulkan RenderSystem backport and those are actually borrowed from the Vulkan Memory Allocator library. There you can also find all the subtleties regarding Vulkan, that I did not bother copying to the Ogre manual.
While these flags were named with Vulkan in mind, they map surprisingly well to the Ogre ones and, most importantly, to the actual Ogre usage. After refining the meaning, it allowed dropping several superficial copies and readbacks in the D3D11 & D3D9 RenderSystems. Yes, these even map well to D3D9.
Super-fast debug drawing
Debug drawing in Ogre has been refactored and is now abstracted by the DebugDrawer API with a DefaultDebugDrawer implementation.
One advantage of this is that debug drawing code will not be sprayed across core classes. At least with 1.13 – for now we keep things as is not to break any obscure use-cases.
The main advantage however is, that debug drawing is now properly batched – whereas there was one draw-call per WireBox previously, there is now one draw-call for all wireboxes in the scene. This is also true for coordinate crosses and camera frustums.
Ogre can now be built using the latest Emscripten SDK, thaks to a contribution by Gustavo Branco
The Config dialog on Windows & Linux was updated to use the new Ogre logo
While revising the depth-texture implementation, I noticed that we would take advantage of that feature for performance instead of quality. With depth-textures the GPU can perform bilinear interpolation of the depth-test, so a single sample (tap) roughly corresponds to a classical 4-tap PCF in the shader. So what we did was just doing a 1 sample instead of 4. However for hardware capable of depth-textures, performance is typically not an issue, so we should rather improve quality.
The images below show crops from the ShaderSystem sample at 200%. On the left, you see the old setting, while the new setting is in the middle. On the right, you see the 4-tap shader fallback used when depth-textures are not available i.e. on D3D9 and GLES2.
Yeah, so the other news is that D3D11 finally got depth-texture (PF_DEPTH) support as well.
But what if you need to support RenderSystems without PF_DEPTH or you are on GLES2 where PF_DEPTH support is not guaranteed. Well, Ogre will now gracefully fall back to the closeset non-depth format: e.g. PF_DEPTH16 > PF_L16 and the RTSS will then deal with the differences.
While at it, I also updated the default shadow material settings to be more robust as in shadow aliasing artefacts:
I took another look at the documentation and added a CI test to detect docstring inconsistencies like undocumented or superficial parameters. This should help improving the documentation quality of external and my own pull-requests.While at it I also added doxygen groups to several large classes. These allow tying related methods together. See e.g. the Material class:
Next, it kind of bothered me that one has to write so verbose code, when using the Python bindings, so I tried to take advantage of Python protocols:
# Now, instead of specifying the type as before
vp.setBackgroundColour(Ogre.ColourValue(.3, .3, .3))
# you can do
vp.setBackgroundColour((.3, .3, .3))
# or even
Also, bytes objects are now supported where raw pointers are expected in the API:
# so you can do
arr = np.zeros((256, 256, 3), dtype=np.uint8)
ogre_img.loadDynamicImage(arr, 256, 256, Ogre.PF_BYTE_RGB)
OgreUnifiedShader as a Cg replacement
In an effort to provide an modern alternative for Cg and to reduce the maintenance overhead of the Ogre internal shaders, I created the OgreUnifiedShader.h that allows writing cross-platform shaders. It is greatly inspired by the shiny library for Ogre and the shaderc tool of bgfx. However, in contrast to the latter this header is fully self-contained. All you need to do is #include it – no need to run an additional tool. It also has the advantage that you can run your shader through the standard c preprocessor (cpp) to see what the transformed shader looks like.
Just as bgfx, I opted for GLSL as the least common denominator between the shader languages. That is with some preprocessor based abstractions on top:
Declare Samplers with SAMPLER2D/3D/CUBE/.. macros instead of sampler2D/3D/Cube/..
Use the HLSL style mul(x, y) for matrix multiplication
Use mtxFromRows to construct matrices
Declare parameters with IN/ OUT macros instead of attribute/ varying
Use the MAIN_PARAMETERS & MAIN_DECLARATION macros instead of void main()
Here, I tried to maintain compatibility with bgfx where possible.
For an example of usage, see this PR, where I converted the Light Shafts Demo from Cg to HLSL & GLSL. As you can see there is still some room for improvements on the Ogre Material side.
Anyway, this allowed to drop 1800 lines (#1663) of shader code from the RTSS and we now have arrived at a single, GLSL based, shader library. When I joined Ogre there were 4 RTSS implementations (GLSL, GLSLES, HLSL, Cg) – with individual, subtle, bugs.
blender2ogre for Blender 2.8x
Thanks to a contribution by “Grodou” blender2ogre gained back the ability to export textures with Blender 2.8x, which is notable as we need to read from the node-based shaders for this. Together with some additional fixes by yours truly and the initial porting done by Paul Gerke, this brings exporting with Blender 2.8x roughly at the same level as with Blender 2.7x.
However, we can now take advantage of the texture semantics one gets from the Cycles materials. Thereofore, blender2ogre is able to correctly export emissive textures and, notably, normal maps.
The difference in appearance that you see above is due to the missing gamma handling. Also, to fully match what you see in Blender, we need add support for metalness and roughness maps.
The 1.12.7 point release kept its focus on integration. Notably, it ships the new Metal RenderSystem, that was discussed in a previous post. Also there are the following notable changes:
Improved Terrain Rendering: The lighting computation was pretty messed up before, which I could fix. See the following screens for comparison. Also, now vertex compression (60% less data per vertex) is used with OpenGL, too.
Filament shader support: Thanks to a contribution of SNiLD, I could extend the existing PBR sample to showcase the usage of Filament PBR shaders. The images below also show the existing glTF2 based material and how far you get by only using plain ogre materials.
New stable CSM Sample: I found another interesting Demo on the Forums and added it as a Sample to the Sample Browser. This time it is “Cascaded Shadow Mapping” which resembles the implementation you get in the CryEngine. This is a different take on the PSSM Shadow Mapping Algorithm, which is best explained by visualizing it
Debug view in the PSSM RTShader: While working on the CSM Sample, I found the debug split view particularly useful. Therefore, you can now visualize how the PSSM Shadow splits are placed in your scene – check out the updated ShaderSystem Sample.
OgreMeshViewer: LOD preview
If your mesh contains LOD levels, Meshviewer will now display a new tab, highlighting the currently active level
If you would like to know how to automatically generate LOD for your meshes, see the updated Ogre Tutorial.