playcanvas/build/playcanvas/src/scene/shader-lib/glsl/chunks/gsplat/vert/gsplatSogsData.js

PlayCanvas WebGL game engine

var gsplatSogsDataVS = `
uniform highp usampler2D packedTexture;
uniform vec3 means_mins;
uniform vec3 means_maxs;
uniform vec3 scales_mins;
uniform vec3 scales_maxs;
vec4 unpackU32(uint v) {
	return vec4(
		float((v >> 24u) & 0xFFu) / 255.0,
		float((v >> 16u) & 0xFFu) / 255.0,
		float((v >> 8u) & 0xFFu) / 255.0,
		float(v & 0xFFu) / 255.0
	);
}
uvec4 packedSample;
vec3 readCenter(SplatSource source) {
	packedSample = texelFetch(packedTexture, source.uv, 0);
	vec3 l = unpackU32(packedSample.x).xyz;
	vec3 u = unpackU32(packedSample.y).xyz;
	vec3 n = (l * 255.0 + u * 255.0 * 256.0) / 65535.0;
	vec3 v = mix(means_mins, means_maxs, n);
	return sign(v) * (exp(abs(v)) - 1.0);
}
const float norm = 2.0 / sqrt(2.0);
void readCovariance(in SplatSource source, out vec3 covA, out vec3 covB) {
	vec4 qdata = unpackU32(packedSample.z);
	vec3 sdata = unpackU32(packedSample.w).xyz;
	vec3 abc = (qdata.xyz - 0.5) * norm;
	float d = sqrt(max(0.0, 1.0 - dot(abc, abc)));
	uint mode = uint(qdata.w * 255.0 + 0.5) - 252u;
	vec4 quat = (mode == 0u) ? vec4(d, abc) :
				((mode == 1u) ? vec4(abc.x, d, abc.yz) :
				((mode == 2u) ? vec4(abc.xy, d, abc.z) : vec4(abc, d)));
	mat3 rot = quatToMat3(quat);
	vec3 scale = exp(mix(scales_mins, scales_maxs, sdata));
	mat3 M = transpose(mat3(
		scale.x * rot[0],
		scale.y * rot[1],
		scale.z * rot[2]
	));
	covA = vec3(dot(M[0], M[0]), dot(M[0], M[1]), dot(M[0], M[2]));
	covB = vec3(dot(M[1], M[1]), dot(M[1], M[2]), dot(M[2], M[2]));
}
`;

export { gsplatSogsDataVS as default };