  High-resolution simulations often rely on the Adaptive Mesh Resolution (AMR)
technique to optimize memory consumption versus attainable precision. While
this technique allows for dramatic improvements in terms of computing
performance, the analysis and visualization of its data outputs remain
challenging. The lack of effective volume renderers for the octree-based AMR
used by the RAMSES simulation program has led to the development of the
solutions presented in this paper. Two custom algorithms are discussed, based
on the splatting and the ray-casting techniques. Their usage is illustrated in
the context of the visualization of a high-resolution, 6000-processor
simulation of a Milky Way-like galaxy. Performance obtained in terms of memory
management and parallelism speedup are presented.
