Khronos Celebrates 20 Years
August 8, 2012, Siggraph, Los Angeles—We talked with Barthold Lichtenbelt from Nvidia and Khronos at their 20th anniversary celebration. In addition to looking at their accomplishments in the past two decades, they continue to drive open standards into the industry.
The latest releases include OpenGL ES 3.0, OpenGL 4.3, texture compression for both Open GL and OpenGL ES, CLU utility start up reduction, Collada importer/exporter, and new working groups for vision acceleration and sensor fusion. The various open standards define APIs for various graphics, video, and sensor processing. The organization has grown to over a hundred member companies.
For example, the Open GL ES started as a working group in ’02 and about every three years they release a new revision. This standard addresses graphic and video on mobile platforms, and last year, high-end 3-D content became possible for mobile devices through the OpenGL ES interfaces. Open GL ES is used in Android, iOS, and other mobile and embedded OS, except for Windows. It has about a 90 percent share of the mobile market.
The goals for the next revision include incorporating more of the feature set from Open GL 3.3/4.0 to reduce the need for extensions. It will be back compatible with previous versions, but will have tighter requirements for supported features. These changes will reduce implementation variability. The working group includes GPU designers, SoC vendors, OS vendors, tools and game engine developers, and other hardware and software makers. The complete list of enhancements and changes are available at the website.
In addition to the new features, the working groups will work to unify the Open GL and Open GL ES functions and calls and will converge the APIs where needed. New debug functions and failure isolation are some of the envisioned additions. Texture compression as one of the keys to improved interoperability. ETC2/EAC is required for the current versions and ASTC is shipping as an extension. These texture compression functions will be integrated into the core Open GL/ ES code.
To confirm the quality and reproducibility, a Kishonti GL benchmark 3.0 is also being released. It includes occlusion query, deferred rendering using multiple render targets and depth textures, and instanced drawings. As a result, the details and realism should be much higher without needing a complete replacement of your mobile device.
Open GL 4.3 enables further improvements in 3-D, from early fixed functions, to vertex and fragment shaders, to geometry shaders. Now the hardware and software can move from surface realism to shape realism with tessellation and compute functions in the latest release. This brings advanced 3-D functionality to the desktop.
The latest release enables higher fidelity rendering, compute shaders to move more graphics tasks to the GPU and freeing up more MIPS in the CPU for other functions. It also enables mobile applications to run on the desktop. The changes and new functions will provide more texture functionality and better image processing. New “view” functions allow texture storage in multiple ways and enable conceptual split of texture objects.
New buffers enable all shader stages to read and write to arbitrarily to very large buffers. Other buffer functions apply controls on access and bindings. New tools are available to support the new functions in Open GL 4.2 including GLView, GLEW, and GLIntercept. Other documentation and support are at the website. (also see www.opengl-tutorial.org/)
Moving from the graphics, OpenCL now has CLU, an API for OpenCL prototyping. This framework is made to encourage heterogeneous computing and highly parallel programs. The framework includes a number of APIs for setting up and controlling multiple compute devices of arbitrary types, both CPUs and GPUs. The tools include high-level model and intermediate-level language representations.
The efforts to create a framework for development in parallel processors is trying to address the many challenges of migrating from linear to parallel processing. CLU simplifies program initialization, source code compilation, and calling kernels with their arguments. It doesn’t provide same source development, nor does it act as a wrapper or extend the kernel language. It also doesn’t provide an intermediate representation, but that is coming from the OpecCL-SPIR group.
Collada is an XML database schema for 3-d assets. The tools are being used in many production environments, and is in process to become an ISO standard for CAD. The OpenCollada importer and exporter and test suites are now available on github.
https://github.com/khronosGroup/OpenCOLLADA and https://github.com/KhronosGroup/COLLADA-CTS The database interfaces to JSON and WebGL.
The database aspect exposes the need for a 3-D transport standard. The codecs and compression requirements do not exist yet. In audio, the standard is MP3, video is h.264, images use png or jpeg. The data density of 3-D calls for high-level compression and load on demand textures and geometry.
Finally, the organization is working on standards for vision and sensing. Visual-based augmented reality will need vision and other sensors to add data to the local landscape. OpenVL will provide access to the Open CV libraries and enable hardware acceleration of algorithms. The specification is planning for a draft specification by the end of the year.
The sensor fusion group is aiming for a standard API for sensors. StreamInput will take sensor data to minimize or reject anomalies and increase accuracy. Current activities include semantics and taxonomy, defining node interfaces, and stating point proposals. The first pass specification is expected in spring ’13.
