To control the amount of displacement, a scale property has been added to the displacementTexture object scheme: The latter will cause problems because it is still possible for a triangle to be visible even if all its corners are outside the view.) To account for displacement, I also tested the same vertices with maximum displacement applied. (This is not the same as testing if any control point is inside the camera frustum, as I have seen suggested elsewhere. I solved this by testing if all control vertices lie outside one edge of the camera frustum. For convenience, a similar command has been added to the model class, which will apply the settings to all meshes in the model.Īnother problem is culling offscreen polygons so the GPU doesn't have to process millions of extra vertices. This command gives you the ability to set properties that will give a roughly equal distribution of polygons in screen space. Default is 1.0 meters.įarrange: the distance below which tessellation starts increasing. Nearrange: the distance below which tessellation stops increasing. Void Mesh :: SetTessellation ( const float detail, const float nearrange, const float farrange )ĭetail: the higher the detail, the more the polygons are split up. But for tessellation parameters, that is exactly what we need, because the density of the mesh polygons gives us an idea of how detailed the tessellation should be. In fact, the material is the only parameter meshes contained other than vertex or indice data. A mesh object in Turbo is like a surface object in Leadwerks. In Turbo Game Engine, a model contains one of more LODs, and each LOD can have one or more meshes. Each surface has a vertex array, indice array, and a material. Note: In Leadwerks Game Engine, a model is an entity with one or more surfaces. I solved this with some per-mesh setting for tessellation parameters. The reason for this is that cracks will appear when you apply displacement if you try to use a different tessellation level for each polygon. Tessellation should use a single detail level per set of primitives being drawn. The first problem is deciding how much to tessellate an object. I think this is because there are several problems to solve before this technical feature can really be made practical. While there are a ton of examples out there showing how to split a triangle up into smaller triangles, useful discussion and techniques of in-game tessellation is much more rare. I want tessellation to be an every day feature in the new engine, so I decided to work out a useful implementation of it. Before starting voxel ray tracing, another hard problem, I decided to work one some *relatively* easier things for a few days. Now that I have all the Vulkan knowledge I need, and most work is being done with GLSL shader code, development is moving faster.
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