Question

我正在尝试从单独的VAO中绘制VBO。我的目标是为我的几何体的每个顶点获得不同的颜色。但是我的代码仍然是红色的。

我认为我的错误是这段代码片段。请帮帮我找到它。（我已跳过程序和矩阵设置）

设置

            vao = new int[1];
            buffers = new int[2];

            GL.GenVertexArrays(1, vao);
            GL.GenBuffers(2, buffers);

            GL.BindVertexArray(vao[0]);
            GL.EnableVertexAttribArray(0);

            GL.BindBuffer(BufferTarget.ArrayBuffer, buffers[0]);

            unsafe
            {
                fixed (void* verts = quad_strip3)
                {
                    var prt = new IntPtr(verts);

                    GL.BufferData(BufferTarget.ArrayBuffer, new IntPtr(quad_strip3.Length * sizeof(float)), prt,
                        BufferUsageHint.StaticDraw);

                }
            }

            GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, 0, new IntPtr(0));


            GL.BindBuffer(BufferTarget.ArrayBuffer, buffers[1]);

            var r = new Random();

            var colors = new float[quad_strip3.Length];

            for (int i = 0; i < colors.Length; i++)
            {
                colors[i] = (float)r.NextDouble();
            }


            unsafe
            {
                fixed (void* verts = colors)
                {
                    var prt = new IntPtr(verts);

                    GL.BufferData(BufferTarget.ArrayBuffer, new IntPtr(colors.Length * sizeof(float)), prt,
                        BufferUsageHint.StaticDraw);

                }
            }

            GL.VertexAttribPointer(1, 3, VertexAttribPointerType.Float, false, 0, new IntPtr(0));

绘制代码

    GL.BindVertexArray(vao[0]);
    GL.DrawArrays(PrimitiveType.QuadStrip, 0, 26);

顶点着色器

#version 150 core

in vec3 in_Position;
in vec3 in_color;
out vec3 pass_Color;
uniform mat4 projectionMatrix;
uniform mat4 viewMatrix;
uniform mat4 modelMatrix;

void main(void) {
    gl_Position = projectionMatrix * viewMatrix * modelMatrix * vec4(in_Position, 1.0);
    pass_Color = in_color;
}

片段着色器

#version 150 core
in vec3 pass_Color;
out vec4 out_Color;

void main(void) {
    out_Color = vec4(pass_Color, 1.0);
}

Answer 1

Khm ......解决方案非常简单。我只是错过了EnableVertexAttribArray的颜色。

我插入

        GL.EnableVertexAttribArray(1);

之前

        GL.BindBuffer(BufferTarget.ArrayBuffer, buffers[1]);

一切都变得有效了。

将颜色和位置从单独的VBO传递到着色器

1 个答案: