How to generate a normal map from a height map?
If you need the normal at a particular point on a triangle (other than one of the vertices), you can interpolate by weighing the normals of the three vertices by the barycentric coordinates of your point. This is how graphics rasterizers treat the normal for shading.
What are the grayscales of a heightmap?
A heightmap consists of grayscales between 0 (black) and 255 (white). With this tool it is easy to select the different grayscales. Additionally you can enter the highest point of your map into the text field on the right side. The tool then calculates which grayscale relates to which height.
How are polygons generated in a map generator?
I generated maps with polygons, then rasterized them into tile maps that looked like this: Most procedural map generators, including some of my own previous projects, use noise functions (simplex noise, midpoint displacement, fractal, diamond-square, perlin noise, etc.) to generate a height map. I did not do that here.
What to consider when writing a map generator?
When writing your own map generator, think about what which aspects of your map are set by the design and which can vary from map to map. Each of the ideas on this page can be used separately or together in your own map generator project.
Do you need a height map for parallax mapping?
For some rendering techniques, like parallax mapping, it is the height map which is needed. In addition, having the height map is beneficial for editing the normal map. A height map and its normal map, used in the samples below. Recovering the height map boils down to integrating the normal map.
How to calculate the normal of an interior point?
Once you have three different normals (say na, nb, nc), then the normal at any interior point can be computed via barycentric coordinates. Let the vertices be va, vb, vc and the interior point’s barycentric coords be α and β. Then, the interior point v and its normal n are given by: This interpolated normal (n) should be used for Gouraud shading.
Do you have to interpolate surface normal across interior of triangle?
The assumption in that case, is that the entire triangle is flat. This is called flat shading. If, on the other hand, you wish to interpolate the surface normal across the interior of a triangle (used in Gouraud shading ), then you need to have three different normals at the three vertices to begin with.