#version 330
layout(location = 0) in vec3 vertexPos;

uniform mat4 matTotal;
uniform mat4 matModel;

const int MAX_BONES = 100;
uniform mat4 gBones[MAX_BONES];

out vec4 WorldPos;

void main () {
        WorldPos = matModel * vec4(vertexPos, 1.0);
        gl_Position = matTotal * WorldPos;
        ...
}

#version 330

in vec4 WorldPos;

layout(location = 0) out vec4 position;

...

void main() {
    position = WorldPos;
    ...
}