Ogre 1.12.11 was just released. This is the last scheduled release for the 1.12 series and contains many bugfixes and new features. The smaller ones are:

• Gamepad Support in OgreBites
• Restructured GPU Program Script documentation
• Added Camera::setSortMode to account for rendering 2D layers instead of 3D geometry (as with 2D games)

The more notable new features will be presented in more detail in the following

Table of Contents

• Support for animated particles
• Software RenderSystem
• Transparent headless mode on Linux
• Improved Bullet-Ogre integration

Support for animated particles

Support for animating particles via Sprite-sheet textures was added. This enables a whole new class of effects with vanilla Ogre that previously required using particle-universe.

On the screenshots above, you see the Smoke demo, that was updated to showcase the new feature. However, the screenshots do not do full justice to the feature. If you are interested, it is best to download the SampleBrowser build and see the effect in action.

See this post (targeting blender) for an overview of the general technique.

For running the animation, the new TextureAnimator Affector was added.

While at it, I fixed several bugs deep in Ogre that prevented ParticleSystems to be properly treated as shadow casters. Now you can call setCastShadows as with any other entity and things will just work (see last image).

Software RenderSystem

Did you ever want to launch a Python Interpreter from your Shader or make HTTP requests per-pixel? Well, the wait is finally over – with the new TinyRenderSystem in Ogre 1.12.11 you can.

This render-system is based on the tinyrenderer project, which implements a full software-rasterizer in ~500 loc. If you are curious on how OpenGL works internally, I highly recommend taking a closer look.
For Ogre this had to be doubled to about ~1350 loc, but compared to the Vulkan RenderSystem from 2.x at ~24000 loc it is still tiny (note that this is already after stripping down the v2.3 implementation).

So what do we gain by having that RenderSystem? First it is a nice stress-test for Ogre, as this is a backend implemented in Ogre itself; each Buffer uses the DefaultBuffer implementation and each Texture and RenderWindow is backed by an Ogre::Image.
This makes it also a great fit for offline conversion tools, that want full access to the resources, without needing to actually access the GPU.

Next, this is really useful if you want to Unit-Test a Ogre-based application. Typically, you would need to set-up a headless rendering server (more on that below) to merely check whether your triangle is centered correctly in the frame. This is super easy now.

The screenshots on top, taken from the SampleBrowser, show you how far you can actually get with the RenderSystem. Note that there is no alpha blending, no mipmapping, no user-provided shaders and generally no advanced configuration of the rasterization. So if you are after full-featured software rasterization, you are better off with OpenGL on MESA/llvmpipe.

However, if you want to experiment with the rendering pipeline without being bound by the OpenGL API, this is the way to go. You actually can do the HTTP requests per pixel ;). Also, for creating a new RenderSystem, this is the least amount of reference code to read.

Transparent headless mode on Linux

Rendering on a remote machine over ssh just got easier! Previously ogre required a running X11 instance, which can be a hassle to come by on a machine without any monitors attached (e.g. a GPU server).

Instead of bailing out, Ogre will now merely issue a warning and transparently fall-back to a PBuffer based offscreen window. See this for the technical background.

To be able to do so Ogre must be using EGL instead of GLX, to do so it must be compiled with OGRE_GLSUPPORT_USE_EGL=1. With 1.13, we will be using EGL instead of GLX by default.

Compared with the EGL support recently added in v2.2.5, the implementation is much simpler and does provide any configuration options – but on the plus side the flag above is the only switch to toggle to get it running.

Improved Bullet-Ogre integration

I added a simplified API to the btogre project.

https://github.com/OGRECave/btogre

If you want to have physics on top of your rendering, it is now as simple as:

auto mDynWorld = new BtOgre::DynamicsWorld(gravity_vec);<br>mDynWorld->addRigidBody(weight, yourEntity, BtOgre::CT_SPHERE);

where (as in Bullet) a weight of 0 means static object. Now you can call

mDynWorld->getBtWorld()->stepSimulation(evt.timeSinceLastFrame);

and your objects will interact with each other. Of course if you need more control, the unterlying bullet types are still fully exposed.

Oh, and python bindings are now available too.

As a small Christmas present, I want to show you how easy it has become to make Augmented Reality yourself thanks to Ogre and OpenCV. You should know that my other interest, besides graphics, lies with Computer Vision.
The demo will not rely on proprietary solutions like ARCore or ARKit – all will be done with open-source code that you can inspect an learn from. But lets start with a teaser:

This demo can be put together in less than 50 lines of code, thanks to the OpenCV ovis module that glues Ogre and OpenCV together. Next, I will briefly walk you through the steps that are needed:

First, we have to capture some images to get by the Reality part in AR. Here, OpenCV provides us an unified API that you can use for your Webcam, Industrial Cameras or a pre-recorded video:

import cv2 as cv

imsize = (1280, 720) # the resolution to use
cap = cv.VideoCapture(0)
cap.set(cv.CAP_PROP_FRAME_WIDTH, imsize[0])
cap.set(cv.CAP_PROP_FRAME_HEIGHT, imsize[1])

img = cap.read()[1] # grab an image

then, we have to set up the most crucial part in AR: camera tracking. For this, we will use the ArUco markers – the QR-like quads that surround Sinbad. To no surprise, OpenCV comes with this vision algorithm:

adict = cv.aruco.Dictionary_get(cv.aruco.DICT_4X4_50)
# extract 2D marker-corners from image
corners, ids = cv.aruco.detectMarkers(img, adict)[:2]
# convert corners to 3D transformations [R|t]
rvecs, tvecs = cv.aruco.estimatePoseSingleMarkers(corners, 5, K, None)[:2]

If you look closely, you see that we are using a undefined variable "K" – this is the intrinsic matrix specific for your camera. If you want precise results, you should calibrate your camera to measure those. For instance using the web-service at calibdb.net, which will also just give you the parameters, if your camera is already known.

However, if you just want to continue, you can use the following values that should roughly match any webcam at 1280x720px

import numpy as np
K = np.array(((1000, 0, 640), (0, 1000, 360), (0, 0, 1.)))

So now we have the image and the according 3D transformation for the camera – only the Augmented part is missing. This is where Ogre/ ovis come into play:

# reference the 3D mesh resources
cv.ovis.addResourceLocation("packs/Sinbad.zip")
# create an Ogre window for rendering
win = cv.ovis.createWindow("OgreWindow", imsize, flags=cv.ovis.WINDOW_SCENE_AA)
win.setBackground(img)
# make Ogre renderings match your camera images
win.setCameraIntrinsics(K, imsize)
# create the virtual scene, consisting of Sinbad and a light
win.createEntity("figure", "Sinbad.mesh", tvec=(0, 0, 5), rot=(1.57, 0, 0))
win.createLightEntity("sun", tvec=(0, 0, 100))
# position the camera according to the first marker detected
win.setCameraPose(tvecs[0].ravel(), rvecs[0].ravel(), invert=True)

• You can find the full source-code for the above steps, nicely combined into a main-loop over at OpenCV.
• Alternatively, see this Ogre Sample which works with both Ogre and OpenCV installed via pip

To record the results, you can use win.getScreenshot() and dump it into a cv.VideoWriter – contrary to the name, this works in real-time.

Extending the above code to use cv.aruco.GridBoard as done in the teaser video is left as an exercise for the reader as this is more on the OpenCV side.

Also, If you rather want to use ARCore on Android, there is a Sample how to use the SurfaceTexture with Ogre. Using this, you should be able to modify the hello_ar_java sample from the arcore-sdk to use Ogre.

Ogre 1.12.10 was just released. This “holiday release” contains mostly bugfixes, however there are also some notable additions.

But first, we want thank everyone for their support, as we reached 2000 stars on github.

Table of Contents

• Native GLES2 RenderSystem on Windows
• Improved RenderToVertexBuffer
• Improved ParticleSystem
• Easy 3D Text – aka MovableText out of the box

Native GLES2 RenderSystem on Windows

Due to some work on WGL, you can now build and use the GLES2 RenderSystem on windows without any glue libraries like ANGLE. Consequently it is included in the SDK, so it is easy to try. If you are on NVIDA/ Intel that is – AMD does not support the respective extension. There are no screenshots here, as they would look almost exactly like on GL3+.

Improved RenderToVertexBuffer

Shaders bound to RenderToVertexBuffer (aka. Transform Feedback/ Stream Output) can now use auto parameters (param_named_auto) as in any other stage.

Furthermore the D3D11 implementation was updated and the GPU particles samples now also runs on D3D11 too.

Improved ParticleSystem

The ParticleSystem and the default BillboardParticleRenderer received some optimization regarding Colour and bounds related computations.

Notably, Ogre now uniformly samples the Particle direction, where it would previously incorrectly bias towards the poles:

Easy 3D Text – aka MovableText out of the box

While working on the Particles I got the idea that one could re-purpose the existing BillboardSet for 3D text rendering, and indeed it fits perfectly as you see above. No more snippets from the Wiki needed and everything integrates with the existing API as:

auto font = FontManager::getSingleton().getByName("SdkTrays/Caption");
auto bbs = mSceneMgr->createBillboardSet();

font->putText(bbs, "OGRE\n ...", 10);

Furthermore, I fixed the glyph packing code which now correctly aligns the font-atlas elements, thus obsoleting the character_spacer tuning option.

following the last post about what is going on around Ogre, here is another update. With the Ogre 1.12.8 release, mainly the usability of Ogre was improved with the following additions.

Table of Contents

• Nicer shadows
• Improved Documentation
• Better Python integration
• OgreUnifiedShader as a Cg replacement
• blender2ogre for Blender 2.8x

Nicer shadows

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:

Thanks to an additional round of fixes to the emscripten GLES2 backend, you can also try out the shadow improvements in a WebGL2 capable browser.

Improved Documentation

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:

• before: https://ogrecave.github.io/ogre/api/1.11/class_ogre_1_1_material.html
• after: https://ogrecave.github.io/ogre/api/1.12/class_ogre_1_1_material.html

Speaking of Materials.. did you ever wonder how they work exactly? Well, now you can take a look at

• The Material equations
• The Lighting equations

Better Python integration

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
vp.setBackgroundColour(numpy.zeros(3))
# or even
vp.setBackgroundColour(range(3))

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.