The OctaneRender Team is please to announce the betas 2.55 test release.
EDIT: Added linux and mac downloads
IMPORTANT NOTE: Due to many internal changes, you need to resave your default scene when you first run this new version. When it's started, Click on the top left File menu, then 'Save as Default'. If you do not do this, you might have a different tonemapping response curve or other incorrect defaults.
New features since beta 2.52
There have been a lot of changes since beta 2.52, these are the most important ones:
- We have made a few large scale changes in how geometry is stored in the engine, which are a part of our in progress rewrite of OctaneRender's geometry system to allow for instancing and object transform editing, coming in a next release soon.
These are invisible to the end-user, but could produce errors or artifacts on geometry and changes in render speed and memory use for a given amount of geometry.
Although we have done numerous tests, we specifically like to see what the community thinks and if the speed is better or worse (this could be dependent of the type of scene/geometry),
the differences in stored geometry size on the GPU, and possible artifacts on geometry rendered. - A new node medium node type that can be connected to transmitting materials, being the diffuse material (for diffuse transmission) and the specular material.
There are 2 medium types provided in this release:
- absorption: this is a medium with absorption using beer's law.
This was present in earlier releases as 2 parameters on the specular material, but these are now moved into a medium type node.
NOTE: We have changed the way the absorption node handles the colour to be absorbed.
It now works in a substractive way (as do most other unbiased engines), so you need to configure the inverted colour instead to get an absorption colour desired.
Note that this is not backwards compatible, any OCS projects saved with OctaneRender 2.52 or earlier with absorption configured on a specular material using the old system,
will lose the absorption colour, and it will have to be reconfigured with the new medium node system instead.
Absorption (and SSS) now also allows the use of 3D procedural textures to define the absorption for true volumetric 3D procedural media. - scattering: This is a medium with single-scattering SSS, and also absorption.
You can use it to create true unbiased SSS (although not multiple-scattering yet), using various parameters, including scattering texture, emission texture and various other parameters.
Note that this is single-scattering SSS, not multiple-scattering. It's much faster than the latter, and much more practical, although it does not allow a few things such as volumetric caustics.
We are planning to add a multiple-scattering SSS medium node in the near future, but we think the single-scattering model is much better for all practical scenes.
NOTE: To use a medium for SSS or absorption on a diffuse transmission material, you must first connect a value or colour to your diffuse material's transmission input pin, to turn it into a diffuse transmitter. - absorption: this is a medium with absorption using beer's law.
- IOR (Index of reflection) input on the glossy material.
OctaneRender 2.52 and before provided a slider called 'specular' to define the specular reflection amount on a glossy material.
We have now added a new parameter called 'index' which allows you to use an IOR (index of reflection) value instead, to accurately define the glossyness of a material from a reference measured value.
To keep backwards compatibility, it is switched off by default (the index parameter is set to value '0')
When the value is 0, the glossy material behaves exactly like before and you load existing scenes and make glossy materials using the familiar specular colour method.
If you want to use the IOR system to define specular reflection instead, simply set the specular slider to 1.0 (maximum) and then set a value for the index parameter (usually something between 1.0 and 3.0)
As this release does not include instancing support yet (which was meant for 2.6), we decided to version it as 2.55, being somewhere in the middle

Driver Requirements
This release was built with CUDA 4.0, which means that you should install the latest graphics driver (http://www.nvidia.com/page/drivers.html).
For Linux and Mac OS you also need to install the CUDA Toolkit 4.0 (http://developer.nvidia.com/cuda-toolkit-40).
For Mac OS you also need the latest CUDA 4.0 driver (http://www.nvidia.com/object/mac-driver-archive.html).
Bug fixes & Minor new features
- Corruption of macro input nodes that are linked to the wrong input pin after deleting a macro input node.
- Embedding of HDR images in OCM files.
- Crash with bool inputs for macro nodes.
- Fixed the problem of saving the same frame twice with turntable / daylight animation.
Known issues
- Normal Maps are broken, this will be fixed in the upcoming beta 1.026 releases.
- On Linux the PMC kernel doesn't work on pre-Fermi GPUs (i.e compute model 1.1 - 1.3) - we couldn't find the problem yet, which seems to be a compiler bug.
Download
Due to this being a Test Release, we are only providing zip/tgz archives, no installers.
Windows 64bit: http://www.refractivesoftware.com/rcdow ... in_x64.zip
Windows 32bit: http://www.refractivesoftware.com/rcdow ... _win32.zip
MacOS X 32bit: http://www.refractivesoftware.com/rcdow ... osx_32.zip
GNU/Linux 64bit: http://www.refractivesoftware.com/rcdow ... ux_x64.tgz
Yours,
The OctaneRender® Team.