Files
cup_edit/materials/grid.mat
2025-07-09 10:46:37 +08:00

120 lines
3.3 KiB
Plaintext

material {
name : Grid,
parameters : [
{
type: float,
name: distance
},
{
type: float,
name: lineSize
},
{
type: float3,
name: gridColor
}
],
depthWrite : true,
depthCulling : true,
doubleSided: false,
shadingModel : unlit,
blending : transparent,
variantFilter : [ dynamicLighting, directionalLighting, shadowReceiver, skinning, ssr, stereo ],
culling : none,
instanced : false,
vertexDomain : object
}
vertex {
void materialVertex(inout MaterialVertexInputs material) {
vec3 position = getPosition().xyz;
position.xz *= materialParams.distance;
material.worldPosition.xz = position.xz;
}
}
fragment {
#include "shared.h"
/* the below has been adapted from Blender's overlay_grid_frag.glsl */
#define _1_DIV_SQRTPI 0.5641895835477563
#define RADIUS (_1_DIV_SQRTPI * 1.05)
#define GRID_START (0.5 + RADIUS)
#define GRID_END (0.5 - RADIUS)
#define GRID_STEP(dist) smoothstep(GRID_START, GRID_END, dist)
vec3 getAxes(vec3 point, vec3 fwidthCos, float line_size)
{
vec3 axes_domain = abs(point);
axes_domain /= fwidthCos;
return GRID_STEP(axes_domain - (line_size + materialParams.lineSize));
}
void material(inout MaterialInputs material) {
prepareMaterial(material);
// fade fragments close together
// (i.e. where camera is at a steep angle to the ground plane)
// calculate fragment normal and distance from origin
vec3 V = getWorldPosition().xyz;
float dist = length(V);
V /= dist;
float angle = V.y;
angle = 1.0 - abs(angle);
angle *= angle;
float fade = (1.0 - angle) * 0.5 - smoothstep(0.0, materialParams.distance, dist - materialParams.distance);
// now calculate the distance of the fragment
// to the "grid" line
vec3 P = getWorldPosition().xyz;
vec3 fwidthPos = fwidth(P); // world units covered by 1px in X direction + 1px in Y direction
P += mulMat4x4Float3(getUserWorldFromWorldMatrix(), getWorldCameraPosition()).xyz;
vec2 halfSize = vec2(0.5f, 0.5f);
vec2 gridDomain = abs(mod(P.xz + halfSize, vec2(1,1)) - halfSize);
gridDomain /= fwidthPos.xz;
float lineDist = min(gridDomain.x, gridDomain.y);
float gridAlpha = GRID_STEP(lineDist - materialParams.lineSize);
gridAlpha *= fade;
vec3 planeAxes = vec3(1.0f, 0.0f, 1.0f);
vec3 distanceToAxes = vec3(
dot(P.yz, planeAxes.yz),
0.0f,
dot(P.xy, planeAxes.xy)
);
vec3 dAxes = vec3(
dot(fwidthPos.yz, planeAxes.yz),
0.0f,
dot(fwidthPos.xy, planeAxes.xy)
);
vec3 axes = getAxes(distanceToAxes, dAxes, 0.1);
vec4 color = vec4(
materialParams.gridColor.r,
materialParams.gridColor.g,
materialParams.gridColor.b,
1.0
);
if(axes.x > 1e-8) {
material.baseColor = vec4(AXIS_COLOR_X, 1.0);
} else if(axes.z > 1e-8) {
material.baseColor = vec4(AXIS_COLOR_Z, 1.0);
} else {
material.baseColor = color * gridAlpha;
}
}
}