Article 1 of 7 in our Content series: Cruden’s Dennis Marcus introduces a new series of blog articles on content for real-time simulators.
Whether a driver-in-the-loop (DIL) simulator is being driven by a professional racing driver or by a pool of non-expert drivers in an ADAS study, achieving the highest level of immersion is key to invoking natural driving behavior and extracting the most meaningful results from the test.
Visual feedback is the most important feedback that we can provide to a human driver or passenger in the simulator. For the 3D simulator graphics, that means there is a continuous compromise between database size (how large a virtual world is needed?), frame rate, resolution and the level of detail that can be reproduced.
Too low a frame rate, and the driver does not see a continuous, natural image. Too much detail, and the graphics file becomes too large to render in real time.
That’s critical, because the graphics must be presented to the simulator occupants with the lowest possible latency and the highest possible framerate. In a driving simulator, there must be an excellent correlation between control input and the ‘out of the window’ view. If the driver, for instance, rotates the steering wheel, the image should follow fluently and without any simulator-induced delay.
To create realistic content and achieve the highest level of immersion in a driving simulator, it is important to have experienced 3D artists creating the graphics. Cruden has been designing 3D graphics for its simulators for almost 20 years and employs a team of seven people dedicated to the design of 3D content for automotive and motorsport customers.
These experts know how to manage the trade-offs, and where to put the detail. Track barriers that are close to the driver or key reference points are designed at a higher level of detail than a building or mountain in the far distance, for example.
Cruden has built up a library of virtual public roads, test routes real and imaginary, and race tracks from around the world, and it continues to create bespoke environments for its clients. These usually begin with a full LiDAR scan of both the scenery and, crucially, its surface, which is the key input to the virtual vehicle’s tire model. This enables the DIL simulator to be used as a valuable engineering tool – a world away from a video game, however immersive it may be.
One advantage of Cruden building its content in-house is that the 3D graphics artists work closely with the software developers who build the simulation software that does the rendering. Not all of the companies who create 3D content, also build driving simulators.
To achieve the high quality of simulation that our customers expect, it is essential that the visual system is properly integrated with the other elements of the driving simulator, such as the motion system and the force feedback that you feel on the steering wheel. Cruden does this integration work on a daily basis, which enables us to build the 3D content and rendering software in a better way than companies who focus only on visuals.
As driving simulators have increasingly become used for testing ADAS and autonomous driving technology, the quality of 3D content has become increasingly relevant in the automotive industry. The content that Cruden provides always has a high level of detail, making it ideal for the types of test that have a large group of participants and where the level of immersion is important. For the lower level of detail that is acceptable when engineers create their own road layouts for sensor simulation, for example, Cruden works with third-party software such as Vector Zero, which automates the process.
In a series of articles over the coming months, we’ll further discuss the differences between content for sensor simulation and DIL simulation, reveal how we build our detailed 3D graphics, and explore that vital compromise between details, resolution, frame rate and area extent.
We’ll also go in-depth on how our simulators integrate with content generated by third-party software, including Vector Zero, and see how developments in render technology from the Unity graphics engine are benefiting Cruden simulation.
Whether you’re in race engineering, vehicle dynamics, ADAS development or management, we hope you’ll find the articles entertaining and informative. Stay tuned!
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Other articles in the series:
Article 2: Building 3D tracks and road environments
Links to subsequent articles will be added below as they are published.