Contemporary challenges in the production of digital planetarium shows include real-time rendering realism as well as the creation of authentic content. While interactive, live performance is a standard feature of professional digital-dome planetarium software today, support for physically correct rendering of astrophysical phenomena is still often limited. Similarly, the tools currently available for planetarium show production do not offer much assistance towards creating scientifically accurate models of astronomical objects. Our paper presents recent results from computer graphics research, offering solutions to contemporary challenges in digital planetarium rendering and modeling. Incorporating these algorithms into the next generation of dome display software and production tools will help advance digital planetariums toward make full use of their potential. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image

Contemporary challenges in the production of digital planetarium shows include real-time rendering realism as well as the creation of authentic content. While interactive, live performance is a standard feature of professional digital-dome planetarium software today, support for physically correct rendering of astrophysical phenomena is still often limited. Similarly, the tools currently available for planetarium show production do not offer much assistance towards creating scientifically accurate models of astronomical objects. Our paper presents recent results from computer graphics research, offering solutions to contemporary challenges in digital planetarium rendering and modeling. Incorporating these algorithms into the next generation of dome display software and production tools will help advance digital planetariums toward make full use of their potential. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Picture/Image

Abstract — Interactive visualization and simulation of astrophysical phenomena enable digital planetariums and television documentaries to take their spectators on a journey into deep space and explore the astronomical wonders of our universe in 3D. When thinking about astronomical objects, the first thing that comes to mind is probably stars. Interstellar space, however, is also full of other fascinating phenomena: among the most popular ones are nova and supernova remnants as well as emission and reflection nebulae. What makes these objects so attractive is their intriguingly complex, intricate, and often colorful structure. Observing and investigating them is not only an aesthetic pleasure but helps physicists and astronomers deduct information about our universe and its laws of nature, for example by exploring cosmological effects from the theory of special [13] and general [12] relativity. With the advent of the Hubble Space Telescope (HST), high-quality imagery of many distant objects has become available and popular. Unhindered by the Earth’s atmosphere, the HST is able to capture images of unprecedented resolution. Through the use of filters, objects can be observed at distinct wavelengths, such as the emission lines of various ions outlining the distribution of different elements in the gaseous cloud of astronomical nebulae. Combining multiple such photographs produces the colorful, yet typically falsely-colored images we know from NASA and HST press releases

Fig. 1. The planetary nebula M2-9 is a typical example of a bipolar nebula. Its quasi-symmetric twin lobes of ionized material emanate from a binary star system in its center. Assuming axial symmetry, our reconstruction algorithm uses a single input image (a) to produce a high-resolution 3D visualization that closely resembles the original image when rendered from the same viewpoint (b). From a novel vantage point, the emission along the principal axis of the nebula accumulates and creates a luminous halo (c). As the vantage point approaches the symmetry axis, the received intensity further increases and the perceived shape of the nebula changes toward two entangled rings (d). The resolution of the reconstructed volume is 512 3 voxels. Original image: Bruce Balick (University of Washington), Vincent Icke (Leiden University, The Netherlands), Garrelt Mellema (Stockholm University), and NASA. Abstract—The 3D visualization of astronomical nebulae is a challenging problem since only a single 2D projection is observable from our fixed vantage point on Earth. We attempt to generate plausible and realistic looking volumetric visualizations via a tomographic approach that exploits the spherical or axial symmetry prevalent in some relevant types of nebulae. Different types of symmetry can be implemented by using different randomized distributions of virtual cameras. Our approach is based on an iterative compressed sensing reconstruction algorithm that we extend with support for position-dependent volumetric regularization and linear equality constraints. We present a distributed multi-GPU implementation that is capable of reconstructing high-resolution datasets from arbitrary projections. Its robustness and scalability are demonstrated for astronomical imagery from the Hubble Space Telescope. The resulting volumetric data is visualized using direct volume rendering. Compared to previous approaches, our method preserves a much