opengl - 在顶点着色器opengl中更新顶点位置

Question

我有一个具有以下顶点属性的 VBO：

3 floats for x,y,z
3 floats for r,g,b
2 floats for velocity_x,velocity_y

我想将给定顶点的速度应用到它的位置，在顶点着色器中并且到目前为止已经做到了，但它似乎没有应用任何更改：

                    "#version 330 core\n"
                    "layout (location = 0) in vec3 vertexPos;\n"
                    "layout (location = 1) in vec3 vertexColor;\n"
                    "layout (location = 2) in vec2 vertexVelocity;\n"

                    "vec3 newPosition;\n"
                    "out vec3 vertexColorRes;\n"

                    "uniform mat4 viewMatrix;\n"
                    "uniform mat4 projectionMatrix;\n"

                    "void main()\n"
                    "{\n"
                    "   newPosition = vertexPos + vec3(vertexVelocity, 1.0);\n"
                    "   gl_Position = projectionMatrix * viewMatrix * vec4(newPosition, 1.0);\n"
                    "   vertexColorRes = vertexColor;\n"
                    "}\0"));

似乎是什么问题？