shader_type spatial; // This is a shader with less textures, in case the main one doesn't run on your GPU. // It's mostly a big copy/paste, because Godot doesn't support #include or #ifdef... #include "res://addons/zylann.hterrain/shaders/include/heightmap.gdshaderinc" uniform sampler2D u_terrain_heightmap; uniform sampler2D u_terrain_normalmap; // I had to remove `hint_albedo` from colormap in Godot 3 because it makes sRGB conversion kick in, // which snowballs to black when doing GPU painting on that texture... uniform sampler2D u_terrain_colormap;// : hint_albedo; uniform sampler2D u_terrain_splatmap; uniform mat4 u_terrain_inverse_transform; uniform mat3 u_terrain_normal_basis; uniform sampler2D u_ground_albedo_bump_0 : source_color; uniform sampler2D u_ground_albedo_bump_1 : source_color; uniform sampler2D u_ground_albedo_bump_2 : source_color; uniform sampler2D u_ground_albedo_bump_3 : source_color; uniform float u_ground_uv_scale = 20.0; uniform bool u_depth_blending = true; uniform bool u_triplanar = false; // Each component corresponds to a ground texture. Set greater than zero to enable. uniform vec4 u_tile_reduction = vec4(0.0, 0.0, 0.0, 0.0); varying vec4 v_tint; varying vec4 v_splat; varying vec3 v_ground_uv; vec3 unpack_normal(vec4 rgba) { vec3 n = rgba.xzy * 2.0 - vec3(1.0); // Had to negate Z because it comes from Y in the normal map, // and OpenGL-style normal maps are Y-up. n.z *= -1.0; return n; } // Blends weights according to the bump of detail textures, // so for example it allows to have sand fill the gaps between pebbles vec4 get_depth_blended_weights(vec4 splat, vec4 bumps) { float dh = 0.2; vec4 h = bumps + splat; // TODO Keep improving multilayer blending, there are still some edge cases... // Mitigation: nullify layers with near-zero splat h *= smoothstep(0, 0.05, splat); vec4 d = h + dh; d.r -= max(h.g, max(h.b, h.a)); d.g -= max(h.r, max(h.b, h.a)); d.b -= max(h.g, max(h.r, h.a)); d.a -= max(h.g, max(h.b, h.r)); return clamp(d, 0, 1); } vec3 get_triplanar_blend(vec3 world_normal) { vec3 blending = abs(world_normal); blending = normalize(max(blending, vec3(0.00001))); // Force weights to sum to 1.0 float b = blending.x + blending.y + blending.z; return blending / vec3(b, b, b); } vec4 texture_triplanar(sampler2D tex, vec3 world_pos, vec3 blend) { vec4 xaxis = texture(tex, world_pos.yz); vec4 yaxis = texture(tex, world_pos.xz); vec4 zaxis = texture(tex, world_pos.xy); // blend the results of the 3 planar projections. return xaxis * blend.x + yaxis * blend.y + zaxis * blend.z; } vec4 depth_blend2(vec4 a, vec4 b, float t) { // https://www.gamasutra.com // /blogs/AndreyMishkinis/20130716/196339/Advanced_Terrain_Texture_Splatting.php float d = 0.1; float ma = max(a.a + (1.0 - t), b.a + t) - d; float ba = max(a.a + (1.0 - t) - ma, 0.0); float bb = max(b.a + t - ma, 0.0); return (a * ba + b * bb) / (ba + bb); } vec4 texture_antitile(sampler2D tex, vec2 uv) { float frequency = 2.0; float scale = 1.3; float sharpness = 0.7; // Rotate and scale UV float rot = 3.14 * 0.6; float cosa = cos(rot); float sina = sin(rot); vec2 uv2 = vec2(cosa * uv.x - sina * uv.y, sina * uv.x + cosa * uv.y) * scale; vec4 col0 = texture(tex, uv); vec4 col1 = texture(tex, uv2); //col0 = vec4(0.0, 0.0, 1.0, 1.0); // Periodically alternate between the two versions using a warped checker pattern float t = 0.5 + 0.5 * sin(uv2.x * frequency + sin(uv.x) * 2.0) * cos(uv2.y * frequency + sin(uv.y) * 2.0); // Using depth blend because classic alpha blending smoothes out details return depth_blend2(col0, col1, smoothstep(0.5 * sharpness, 1.0 - 0.5 * sharpness, t)); } void vertex() { vec2 cell_coords = (u_terrain_inverse_transform * MODEL_MATRIX * vec4(VERTEX, 1)).xz; // Must add a half-offset so that we sample the center of pixels, // otherwise bilinear filtering of the textures will give us mixed results. cell_coords += vec2(0.5); // Normalized UV UV = cell_coords / vec2(textureSize(u_terrain_heightmap, 0)); // Height displacement float h = sample_heightmap(u_terrain_heightmap, UV); VERTEX.y = h; v_ground_uv = vec3(cell_coords.x, h * MODEL_MATRIX[1][1], cell_coords.y) / u_ground_uv_scale; // Putting this in vertex saves 2 fetches from the fragment shader, // which is good for performance at a negligible quality cost, // provided that geometry is a regular grid that decimates with LOD. // (downside is LOD will also decimate tint and splat, but it's not bad overall) v_tint = texture(u_terrain_colormap, UV); v_splat = texture(u_terrain_splatmap, UV); // Need to use u_terrain_normal_basis to handle scaling. NORMAL = u_terrain_normal_basis * unpack_normal(texture(u_terrain_normalmap, UV)); } void fragment() { if (v_tint.a < 0.5) { // TODO Add option to use vertex discarding instead, using NaNs discard; } vec3 terrain_normal_world = u_terrain_normal_basis * unpack_normal(texture(u_terrain_normalmap, UV)); terrain_normal_world = normalize(terrain_normal_world); // TODO Detail should only be rasterized on nearby chunks (needs proximity management to switch shaders) vec2 ground_uv = v_ground_uv.xz; vec4 ab0, ab1, ab2, ab3; if (u_triplanar) { // Only do triplanar on one texture slot, // because otherwise it would be very expensive and cost many more ifs. // I chose the last slot because first slot is the default on new splatmaps, // and that's a feature used for cliffs, which are usually designed later. vec3 blending = get_triplanar_blend(terrain_normal_world); ab3 = texture_triplanar(u_ground_albedo_bump_3, v_ground_uv, blending); } else { if (u_tile_reduction[3] > 0.0) { ab3 = texture(u_ground_albedo_bump_3, ground_uv); } else { ab3 = texture_antitile(u_ground_albedo_bump_3, ground_uv); } } if (u_tile_reduction[0] > 0.0) { ab0 = texture_antitile(u_ground_albedo_bump_0, ground_uv); } else { ab0 = texture(u_ground_albedo_bump_0, ground_uv); } if (u_tile_reduction[1] > 0.0) { ab1 = texture_antitile(u_ground_albedo_bump_1, ground_uv); } else { ab1 = texture(u_ground_albedo_bump_1, ground_uv); } if (u_tile_reduction[2] > 0.0) { ab2 = texture_antitile(u_ground_albedo_bump_2, ground_uv); } else { ab2 = texture(u_ground_albedo_bump_2, ground_uv); } vec3 col0 = ab0.rgb; vec3 col1 = ab1.rgb; vec3 col2 = ab2.rgb; vec3 col3 = ab3.rgb; vec4 w; // TODO An #ifdef macro would be nice! Or copy/paste everything in a different shader... if (u_depth_blending) { w = get_depth_blended_weights(v_splat, vec4(ab0.a, ab1.a, ab2.a, ab3.a)); } else { w = v_splat.rgba; } float w_sum = (w.r + w.g + w.b + w.a); ALBEDO = v_tint.rgb * ( w.r * col0.rgb + w.g * col1.rgb + w.b * col2.rgb + w.a * col3.rgb) / w_sum; ROUGHNESS = 1.0; NORMAL = (VIEW_MATRIX * (vec4(terrain_normal_world, 0.0))).xyz; //ALBEDO = w.rgb; //ALBEDO = v_ground_uv.xyz; }