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Diffstat (limited to 'game/addons/zylann.hterrain/shaders/simple4.gdshader')
-rw-r--r-- | game/addons/zylann.hterrain/shaders/simple4.gdshader | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/game/addons/zylann.hterrain/shaders/simple4.gdshader b/game/addons/zylann.hterrain/shaders/simple4.gdshader new file mode 100644 index 0000000..6c28b77 --- /dev/null +++ b/game/addons/zylann.hterrain/shaders/simple4.gdshader @@ -0,0 +1,329 @@ +shader_type spatial; + +// This is the reference shader of the plugin, and has the most features. +// it should be preferred for high-end graphics cards. +// For less features but lower-end targets, see the lite version. + +#include "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; +uniform sampler2D u_terrain_splatmap; +uniform sampler2D u_terrain_globalmap : source_color; +uniform mat4 u_terrain_inverse_transform; +uniform mat3 u_terrain_normal_basis; + +// the reason bump is preferred with albedo is, roughness looks better with normal maps. +// If we want no normal mapping, roughness would only give flat mirror surfaces, +// while bump still allows to do depth-blending for free. +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 sampler2D u_ground_normal_roughness_0; +uniform sampler2D u_ground_normal_roughness_1; +uniform sampler2D u_ground_normal_roughness_2; +uniform sampler2D u_ground_normal_roughness_3; + +// Had to give this uniform a suffix, because it's declared as a simple float +// in other shaders, and its type cannot be inferred by the plugin. +// See https://github.com/godotengine/godot/issues/24488 +uniform vec4 u_ground_uv_scale_per_texture = vec4(20.0, 20.0, 20.0, 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); + +uniform float u_globalmap_blend_start; +uniform float u_globalmap_blend_distance; + +uniform vec4 u_colormap_opacity_per_texture = vec4(1.0, 1.0, 1.0, 1.0); + +varying float v_hole; +varying vec3 v_tint0; +varying vec3 v_tint1; +varying vec3 v_tint2; +varying vec3 v_tint3; +varying vec4 v_splat; +varying vec2 v_ground_uv0; +varying vec2 v_ground_uv1; +varying vec2 v_ground_uv2; +varying vec3 v_ground_uv3; +varying float v_distance_to_camera; + + +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; +} + +vec4 pack_normal(vec3 n, float a) { + n.z *= -1.0; + return vec4((n.xzy + vec3(1.0)) * 0.5, a); +} + +// 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_value, float a_bump, vec4 b_value, float b_bump, float t) { + // https://www.gamasutra.com + // /blogs/AndreyMishkinis/20130716/196339/Advanced_Terrain_Texture_Splatting.php + float d = 0.1; + float ma = max(a_bump + (1.0 - t), b_bump + t) - d; + float ba = max(a_bump + (1.0 - t) - ma, 0.0); + float bb = max(b_bump + t - ma, 0.0); + return (a_value * ba + b_value * bb) / (ba + bb); +} + +vec2 rotate(vec2 v, float cosa, float sina) { + return vec2(cosa * v.x - sina * v.y, sina * v.x + cosa * v.y); +} + +vec4 texture_antitile(sampler2D albedo_tex, sampler2D normal_tex, vec2 uv, out vec4 out_normal) { + 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 = rotate(uv, cosa, sina) * scale; + + vec4 col0 = texture(albedo_tex, uv); + vec4 col1 = texture(albedo_tex, uv2); + vec4 nrm0 = texture(normal_tex, uv); + vec4 nrm1 = texture(normal_tex, uv2); + //col0 = vec4(0.0, 0.5, 0.5, 1.0); // Highlights variations + + // Normals have to be rotated too since we are rotating the texture... + // TODO Probably not the most efficient but understandable for now + vec3 n = unpack_normal(nrm1); + // Had to negate the Y axis for some reason. I never remember the myriad of conventions around + n.xz = rotate(n.xz, cosa, -sina); + nrm1 = pack_normal(n, nrm1.a); + + // Periodically alternate between the two versions using a warped checker pattern + float t = 1.2 + + sin(uv2.x * frequency + sin(uv.x) * 2.0) + * cos(uv2.y * frequency + sin(uv.y) * 2.0); // Result in [0..2] + t = smoothstep(sharpness, 2.0 - sharpness, t); + + // Using depth blend because classic alpha blending smoothes out details. + out_normal = depth_blend2(nrm0, col0.a, nrm1, col1.a, t); + return depth_blend2(col0, col0.a, col1, col1.a, t); +} + +void vertex() { + vec4 wpos = MODEL_MATRIX * vec4(VERTEX, 1); + vec2 cell_coords = (u_terrain_inverse_transform * wpos).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 (#183) + 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; + wpos.y = h; + + vec3 base_ground_uv = vec3(cell_coords.x, h * MODEL_MATRIX[1][1], cell_coords.y); + v_ground_uv0 = base_ground_uv.xz / u_ground_uv_scale_per_texture.x; + v_ground_uv1 = base_ground_uv.xz / u_ground_uv_scale_per_texture.y; + v_ground_uv2 = base_ground_uv.xz / u_ground_uv_scale_per_texture.z; + v_ground_uv3 = base_ground_uv / u_ground_uv_scale_per_texture.w; + + // 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) + vec4 tint = texture(u_terrain_colormap, UV); + v_hole = tint.a; + v_tint0 = mix(vec3(1.0), tint.rgb, u_colormap_opacity_per_texture.x); + v_tint1 = mix(vec3(1.0), tint.rgb, u_colormap_opacity_per_texture.y); + v_tint2 = mix(vec3(1.0), tint.rgb, u_colormap_opacity_per_texture.z); + v_tint3 = mix(vec3(1.0), tint.rgb, u_colormap_opacity_per_texture.w); + 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)); + + v_distance_to_camera = distance(wpos.xyz, CAMERA_POSITION_WORLD); +} + +void fragment() { + if (v_hole < 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); + vec3 normal = terrain_normal_world; + + float globalmap_factor = clamp((v_distance_to_camera - u_globalmap_blend_start) + * u_globalmap_blend_distance, 0.0, 1.0); + globalmap_factor *= globalmap_factor; // slower start, faster transition but far away + vec3 global_albedo = texture(u_terrain_globalmap, UV).rgb; + ALBEDO = global_albedo; + + // Doing this branch allows to spare a bunch of texture fetches for distant pixels. + // Eventually, there could be a split between near and far shaders in the future, + // if relevant on high-end GPUs + if (globalmap_factor < 1.0) { + vec4 ab0, ab1, ab2, ab3; + vec4 nr0, nr1, nr2, nr3; + + 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_uv3, blending); + nr3 = texture_triplanar(u_ground_normal_roughness_3, v_ground_uv3, blending); + + } else { + if (u_tile_reduction[3] > 0.0) { + ab3 = texture_antitile( + u_ground_albedo_bump_3, u_ground_normal_roughness_3, v_ground_uv3.xz, nr3); + } else { + ab3 = texture(u_ground_albedo_bump_3, v_ground_uv3.xz); + nr3 = texture(u_ground_normal_roughness_3, v_ground_uv3.xz); + } + } + + if (u_tile_reduction[0] > 0.0) { + ab0 = texture_antitile( + u_ground_albedo_bump_0, u_ground_normal_roughness_0, v_ground_uv0, nr0); + } else { + ab0 = texture(u_ground_albedo_bump_0, v_ground_uv0); + nr0 = texture(u_ground_normal_roughness_0, v_ground_uv0); + } + if (u_tile_reduction[1] > 0.0) { + ab1 = texture_antitile( + u_ground_albedo_bump_1, u_ground_normal_roughness_1, v_ground_uv1, nr1); + } else { + ab1 = texture(u_ground_albedo_bump_1, v_ground_uv1); + nr1 = texture(u_ground_normal_roughness_1, v_ground_uv1); + } + if (u_tile_reduction[2] > 0.0) { + ab2 = texture_antitile( + u_ground_albedo_bump_2, u_ground_normal_roughness_2, v_ground_uv2, nr2); + } else { + ab2 = texture(u_ground_albedo_bump_2, v_ground_uv2); + nr2 = texture(u_ground_normal_roughness_2, v_ground_uv2); + } + + vec3 col0 = ab0.rgb * v_tint0; + vec3 col1 = ab1.rgb * v_tint1; + vec3 col2 = ab2.rgb * v_tint2; + vec3 col3 = ab3.rgb * v_tint3; + + vec4 rough = vec4(nr0.a, nr1.a, nr2.a, nr3.a); + + vec3 normal0 = unpack_normal(nr0); + vec3 normal1 = unpack_normal(nr1); + vec3 normal2 = unpack_normal(nr2); + vec3 normal3 = unpack_normal(nr3); + + 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 = ( + w.r * col0.rgb + + w.g * col1.rgb + + w.b * col2.rgb + + w.a * col3.rgb) / w_sum; + + ROUGHNESS = ( + w.r * rough.r + + w.g * rough.g + + w.b * rough.b + + w.a * rough.a) / w_sum; + + vec3 ground_normal = /*u_terrain_normal_basis **/ ( + w.r * normal0 + + w.g * normal1 + + w.b * normal2 + + w.a * normal3) / w_sum; + // If no splat textures are defined, normal vectors will default to (1,1,1), + // which is incorrect, and causes the terrain to be shaded wrongly in some directions. + // However, this should not be a problem to fix in the shader, + // because there MUST be at least one splat texture set. + //ground_normal = normalize(ground_normal); + // TODO Make the plugin insert a default normalmap if it's empty + + // Combine terrain normals with detail normals (not sure if correct but looks ok) + normal = normalize(vec3( + terrain_normal_world.x + ground_normal.x, + terrain_normal_world.y, + terrain_normal_world.z + ground_normal.z)); + + normal = mix(normal, terrain_normal_world, globalmap_factor); + + ALBEDO = mix(ALBEDO, global_albedo, globalmap_factor); + ROUGHNESS = mix(ROUGHNESS, 1.0, globalmap_factor); + + // Show splatmap weights + //ALBEDO = w.rgb; + } + // Highlight all pixels undergoing no splatmap at all +// else { +// ALBEDO = vec3(1.0, 0.0, 0.0); +// } + + NORMAL = (VIEW_MATRIX * (vec4(normal, 0.0))).xyz; +} |