playcanvas/build/playcanvas/src/scene/shader-lib/glsl/chunks/common/vert/skin.js

PlayCanvas WebGL game engine

var skinVS = `
attribute vec4 vertex_boneWeights;
attribute vec4 vertex_boneIndices;
uniform highp sampler2D texture_poseMap;
void getBoneMatrix(const in int width, const in int index, out vec4 v1, out vec4 v2, out vec4 v3) {
	int v = index / width;
	int u = index % width;
	v1 = texelFetch(texture_poseMap, ivec2(u + 0, v), 0);
	v2 = texelFetch(texture_poseMap, ivec2(u + 1, v), 0);
	v3 = texelFetch(texture_poseMap, ivec2(u + 2, v), 0);
}
mat4 getSkinMatrix(const in vec4 indicesFloat, const in vec4 weights) {
	int width = textureSize(texture_poseMap, 0).x;
	ivec4 indices = ivec4(indicesFloat + 0.5) * 3;
	vec4 a1, a2, a3;
	getBoneMatrix(width, indices.x, a1, a2, a3);
	vec4 b1, b2, b3;
	getBoneMatrix(width, indices.y, b1, b2, b3);
	vec4 c1, c2, c3;
	getBoneMatrix(width, indices.z, c1, c2, c3);
	vec4 d1, d2, d3;
	getBoneMatrix(width, indices.w, d1, d2, d3);
	vec4 v1 = a1 * weights.x + b1 * weights.y + c1 * weights.z + d1 * weights.w;
	vec4 v2 = a2 * weights.x + b2 * weights.y + c2 * weights.z + d2 * weights.w;
	vec4 v3 = a3 * weights.x + b3 * weights.y + c3 * weights.z + d3 * weights.w;
	float one = dot(weights, vec4(1.0));
	return mat4(
		v1.x, v2.x, v3.x, 0,
		v1.y, v2.y, v3.y, 0,
		v1.z, v2.z, v3.z, 0,
		v1.w, v2.w, v3.w, one
	);
}
`;

export { skinVS as default };