View‐Dependent Realtime Rendering of Procedural Facades with High Geometric Detail

Abstract

We present an algorithm for realtime rendering of large-scale city models with procedurally generated facades. By using highly detailed assets like windows, doors, and decoration such city models can provide an extremely high geometric level of detail but on the downside they also consist of billions of polygons which makes it infeasible to even store them as explicit polygonal meshes. Moreover, when rendering urban scenes usually only a very small fraction of the city is actually visible which calls for effective culling mechanisms. For procedural textures there are efficient screen space techniques that evaluate, e.g., a split grammar on a per-pixel basis in the fragment shader and thus render a textured facade in a view dependent manner. We take this idea further by introducing 3D geometric detail in addition to flat textures. Our approach is a two-pass procedure that first renders a flat procedural facade. During rasterization the fragment shader triggers the instantiation of a detailed asset whenever a geometric facade element is potentially visible. The set of instantiated detail models are then rendered in a second pass. The major challenges arise from the fact that geometric details belonging to a facade can be visible even if the base polygon of the facade itself is not visible. Hence we propose measures to conservatively estimate visibility without introducing excessive redundancy. We further extend our technique by a simple level of detail mechanism that switches to baked textures (of the assets) depending on the distance to the camera. We demonstrate that our technique achieves realtime frame rates for large-scale city models with massive detail on current commodity graphics hardware.

Multi-Scale Procedural Animations of Microtubule Dynamics Based on Measured Data

“…The computational effort increases with the size and complexity of the modeled structure. A frequently used way to reduce the computation is to only generate what is currently visible in the viewing frustum of the camera [23].…”

A Survey of Algorithmic Shapes

“…Parallel generation is especially useful in an urban context, with scenes with high complexity and detail. The work of LARS KRECKLAU et al used GPU-accelerated generation in the context of generating and rendering highly detailed building facades [45]; the work of ZHENGZHENG KUANG et al proposes a memory-efficient procedural representation of urban buildings for real-time visualization [46].…”

Built by Algorithms – State of the Art Report on Procedural Modeling –

“…Parallel generation is especially useful in an urban context, with scenes with high complexity and detail. The work of LARS KRECKLAU et al (2013) used gpu accelerated generation in the context of generating and rendering high detailed building façades; the work of ZHENGZHENG KUANG et al (2013) proposes a memory-efficient procedural representation of urban buildings for real-time visualization.…”