# From Google Earth Studio to Hologram: A Pipeline for Architectural Visualization
## 4 Discussion  
Our results validate the feasibility and visual quality of the proposed pipeline, which converts photogrammetrically derived 3D imagery from Google Earth Studio into immersive holographic stereograms without requiring on-site scanning or modeling. We demonstrated the feasibility of leveraging the photogrammetrically reconstructed urban environments of Google Earth Studio to create high-quality full-color digital holographic stereograms using the CHIMERA printing system. Our method addressed several critical limitations of traditional 3D data-acquisition techniques, such as the time- and labor-intensive nature of LiDAR scanning, drone photogrammetry, and manual 3D modeling.  
By defining a 120\({}^{\circ}\) capture arc centered on the frontal axis of each building and sampling 13 key camera positions, we generated a sufficient number of parallax-rich perspective images for effective holographic printing. Each image was rendered in Earth Studio at a resolution suitable for holographic display, and the resulting 721-frame sequence was processed using custom software to generate the hogel data. Further, the use of Ultimate U04 isopachromatic plates combined with an RGB SLM-based CHIMERA system yielded holograms with excellent color fidelity, sharpness, and parallax response. The 250 um hogel resolution ensured that the hogel grid was imperceptible to the naked eye, contributing to a seamless visual experience. Upon reconstruction with RGB LEDs, the resulting holograms exhibited vivid 3D depth cues and realistic rendering of architectural forms, as confirmed by qualitative evaluation of both the Basilica de la Sagrada Familia and the Arc de Triomphe.  
A key innovation in this pipeline is the use of freely accessible global 3D datasets to produce high-resolution holograms without requiring physical data capture. Despite the original intent of Earth Studio as a cinematographic tool, its ability to lock camera targets and export frame sequences with consistent focal lengths and angular precision has proven critical for hologram generation. Furthermore, the external computation of precise camera positions using geospatial data enabled us to overcome the native limitations of  
Figure 8: Full-color CHIMERA holograms of (**a**) Sagrada Familia and (**b**) Arc de Triomphe. Holograms were printed on 15 \(\times\) 20 cm U04 plates under illumination of an RGB LED.  
Earth Studio in terms of angular control, thereby creating a reliable pipeline for consistent data acquisition.  
However, certain limitations must be acknowledged. The current method only describes half-parallax holography because the camera trajectory is confined to a horizontal arc. Additional vertical viewpoints are required for full-parallax holograms. Moreover, reliance on the accuracy and completeness of photogrammetric data in Google Earth Studio implies that certain urban scenes with occlusions or incomplete geometries may lead to reduced visual quality.  
In real-world scenarios, many buildings are obstructed by surrounding structures, vegetation, or urban infrastructure, which may hinder the completeness of perspective data and impact the quality of holographic reconstructions. While our method is optimized for open-sight conditions and iconic landmarks, which are typically located in areas with preserved visual access, it is not universally applicable to all urban contexts.  
While the method proves particularly effective for prominent landmarks with unobstructed views, its broader applicability is constrained by the quality and completeness of publicly available 3D datasets. In dense urban environments or areas with limited visibility, issues such as occlusions, simplified geometry, or outdated textures can compromise the fidelity of the resulting holograms. To mitigate these limitations, future work should explore hybrid strategies that combine Earth Studio imagery with Supplementary Datasets or AI-assisted scene completion, aiming to extend the utility of the workflow to more complex or partially inaccessible architectural contexts.