![]() ![]() Transform the view direction from world space to tangent spaceįloat3 worldVertexPos = mul(unity_ObjectToWorld, i.vertex).xyz įloat3 worldViewDir = worldVertexPos - _WorldSpaceCameraPos Void vert(inout appdata_full i, out Input o) _NoiseTex("Noise texture", 2D) = "white" Parallax occlusion mapping shader that creates a landscape in a quad Google the mountain and grass textures, but you can use this seamless noise texture: What you need is just a qaud, a noise texture, a mountain texture, and a grass texture. If you are making a game where you are looking out of an aircraft window, then it's unnecessary to build the exact ground geometry with meshes, so you might as well just use a quad and parallax mapping. What we are going to do here is to simulate a landscape. If you are lost, maybe this image might explain it better: This will most likely not be the exact answer, so you might have to change the step size to get a more accurate answer. When the ray is below the geometry, then we need to find the intersection point by using a weighted average of the last point on the ray, which was above the surface.So we have to fire a ray with constant step size and each step we have to check if the ray is below the geometry. We can't do that here because the geometry is described with a grayscale texture. In the previous tutorials we used simple ray/geometry intersections to find where the ray has hit something.If you haven't heard about tangent space, you can say that two of the axis in tangent space are aligned with the u and v coordinates and the third axis is the normal to the surface. ![]() We are going to fire the rays not in global space, not in object space, but in tangent space.Like in the previous tutorials we are going to fire rays to simulate geometry where there is none.But I am going to tell you the basic idea: I'm not going to repeat what's already written, so if you want to read long articles about parallax mapping you can for example read this one: Learn OpenGL - Parallax Mapping. Parallax mapping is a shader technique where you need to be able to write shaders on your own because you can't attach a parallax mapping shader made for bricks to simulate a landscape because you have to really tweak each shader to achive the best result. This is a comparison between bricks with parallax mapping and bricks without parallax mapping: Another solution is to use parallax mapping. But what are you going to do if you for example have a brick wall and want to make those bricks more realistic and can't add more triangles? One solution is to add a normal map, but the result is still kinda flat. When making a game it's really important to use as few triangles as possible. ![]()
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