Hi All, Having seen some recent screenshots from X-Plane 10, I've been thinking about ways to improve our random scenery, in particular buildings.
At present, we have random building scattered over the scenery, based on .ac models, plus the Urban shader. The former are limited in that performance suffers significantly as density increases, and there is little control over their placement. The Urban shader provides an good impression of a complex city-scape, but the sides of the buildings are rather gray, and the visuals suffer at low viewing angles. It also has a significant performance impact. I'm wondering whether there is any mileage in using a variant on the scheme we use for random vegetation to create a cityscape. As you may be aware, the random vetegation uses a small number of geomerties instantiated all over the terrain, and uses a vertex shader (which is much cheaper than a fragment or geometry shader) to provide height, width and texture information. Of course, there's no point at all in doing this unless it provides better performance than the urban shader. The Default materials.xml tree density is 4000m^2, or a tree per 63mx63m square (ish). The trees themselves have similar geometric complexity to a cuboid (same number of vertices), but buildings don't generally have any alpha blending requirements. So to a first level of approximation, we should be able to populate the urban area with textured cubeoids at the same density as the trees for a similar cost performance-wise. To provide more interesting buildings, I'm anticipating using a cuboid per floor, plus a modified cuboid for the roof, so probably ~ 4x the complexity of trees geometrically for a 3 storey building. Obviously there would be XML controls in materials.xml (or a linked XML file) for the length, width, number of floors, textures, and roof. At the same time, I'm anticipating aligning the buildings with the texture, and probably using a second texture as a mask to indicate where buildings may, or may not, be placed. This latter technique may also have applications for the trees, so that trees only appear a the edges of fields, or in the "rough" of golf courses. I'm interested in peoples opinions on this, and in particular what their view is of the current forest and urban shader performance. It may be that my system is unique in that one is cheap and the other expensive, and this is all pointless! Thanks, -Stuart ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
