Current technology, while offering convenience, often require our continuous engagement. Traditional display systems and instrument panels necessitate that users momentarily divert their gaze and refocus, thereby disrupting their concentration. This shift in attention and alteration of the line of sight introduces considerable safety hazards. Consequently, there is a need for innovative display solutions, such as Head-Up Displays (HUDs), which can effectively incorporate critical information within the user’s primary field of view. By reducing distractions, HUDs significantly improve situational awareness and provide crucial real time data which includes speed, navigation instructions, fuel levels, warning alerts and target locations, presented on either the windshield or the combiner. This allows for faster decision making while enhancing user safety.
The prevailing challenges in developing these AR HUD devices stem from numerous design elements and mechanical interferences, which results in inconsistent image quality. The objective is to display dynamic information with wide field of view (FOV) at a virtual distance that is comfortable for the driver’s line of sight. However, packaging a large FOV optical system into the uniquely shaped and increasingly compact dashboard space of vehicles presents significant challenges. This mechanical constraint results in a sub optimal optical path, necessitating multiple iterations of the CAD design, which prolongs the design phase. Due to windshield curvature and variations, prototypes usually exhibit ghosting or double images, non-uniform colour and image distortion. It is imperative to ensure the HUD is legible and has good contrast under all lighting conditions (ambient light and glare caused by internal reflections).
The solution is to implement a virtual first approach, which can be achieved by leveraging the advanced capabilities of CODE V for optical design and optimization, and LightTools for non-sequential illumination and stray light analysis.
CODE V Capabilities: Optical Design, Packaging and Tolerancing
It is possible to export/import CAD files and use it for both visualization and/or ray tracing in sequential or non-sequential models. It allows engineers to spot clearance issues directly in CODE V, eliminating the need to switch to mechanical design software to see packaging issue.
In terms of optical performance and image quality CODE V offers numerous benefits:
- Design Optimization: Global and local optimization features enable engineers to simultaneously optimize large eye box, virtual image distance and distortions while considering packaging constraints.
- Image quality: aberration analysis and ghost image analysis help predict the anomalies caused by the windshield’s complex geometry and coatings. It allows precise tailoring of internal optics to minimize distortions, eliminate double reflections and ensure superior image quality and uniformity.
- High production variability: CODE V can simulate the impact of manufacturing variations of the HUD system with its comprehensive tolerancing tool. This allows engineers to predict production yields and modify designs, if necessary, in the early stages thus significantly reducing costs.

LightTools Capabilities: Illumination, Stray Light Analysis and Visualization
Employing the non-sequential ray tracing, advance scattering models and virtual prototyping capabilities of LightTools, it is possible to simulate light interactions with every surface including dashboard, trim and windshield coatings. Detailed photometric and radiometric analysis helps achieve uniform brightness and colour distribution of the projected image, essential for driver comfort and information clarity.
LightTools has various utilities to help analyze the HUD system:
- Image Processor: a true colour or greyscale image can be used for spatial apodization of a source (PGU). This recreates the true colour image after ray tracing through the optical system. It generates the perceived HUD image which allows for objective assessment.

- Solar Source: Used for the sun effect analysis, it is possible to simulate sun glare under various environmental conditions by varying the angles and locations. This helps to identify and ensure good contrast and readability under all lighting conditions.
- Parameter Analyzer: allows visualization of HUD image motion as driver moves within the eyebox.

The process of developing HUDs can be enhanced through the utilization of CODE V and LightTools, which facilitates the delivery of products that exhibit superior performance. This approach not only accelerates the time to market but also mitigates manufacturing risks, resulting in substantial cost savings.








