java - Opengl 渲染 - z 范围 -1 到 1 之外的任何内容都不会出现？

Question

我在 1 到 -1 范围(z 范围)之外渲染的任何内容都不会出现在屏幕上。我一直在尝试一切，包括使用不同的矩阵来尝试将 1 到 -1 之外的顶点转换到这个范围内，但似乎没有任何效果。

我将把我的代码放在下面。它由一个存储数据的模型类、一个着色器程序(我不会包含它 - 它非常简单)和一个主类组成。

顶点着色器

#version 330 core

in vec4 in_Position;
in vec4 in_Color;

out vec4 pass_Color;

void main(void) {

gl_Position = in_Position;
pass_Color = in_Color;

}

片段着色器

#version 330 core

in vec4 pass_Color;

out vec4 out_Color;

void main(void) {
out_Color = pass_Color;
}

模型类

package util;

import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL15.*;
import static org.lwjgl.opengl.GL30.*;
import static org.lwjgl.opengl.GL20.*;

import java.nio.ByteBuffer;
import java.nio.FloatBuffer;


public class Model {

// Vertex Array ID
int vaoID;
// VBO ID's
int vboVertexID, vboColorID, vboIndexID;
// Vertex Count
int numVertices, numIndices;

public Model(FloatBuffer vertexData, int vertexCount, FloatBuffer colorData, int colorCount, ByteBuffer indexData, int indexCount) {
    // Create the vertex array
    vaoID = glGenVertexArrays();
    // Select the vertex array
    bind();
    // Attach vertex data
    attachVertexData(vertexData, vertexCount);
    // Attach Color data
    attachColorData(colorData, colorCount);
    // Deselect the vertex array
    unbind();
    // Indice attachment
    attachIndexArray(indexData);

    // Set the vertex count
    numVertices = vertexCount;
    numIndices = indexCount;
}

/**
 * Attach some vertex data
 */
public void attachVertexData(FloatBuffer vertexData, int vertexCount) {
    // Create the buffer
    vboVertexID = glGenBuffers();
    // Bind the new buffer
    glBindBuffer(GL_ARRAY_BUFFER, vboVertexID);
    // Give the data to the GPU
    glBufferData(GL_ARRAY_BUFFER, vertexData, GL_STATIC_DRAW);
    // Set the location of the data within the vertex array
    glVertexAttribPointer(0, vertexCount, GL_FLOAT, false, 0, 0);
    // Deselect this buffer
    glBindBuffer(GL_ARRAY_BUFFER, 0);
}

/**
 * Attach some color data
 */
public void attachColorData(FloatBuffer colorData, int colorCount) {
    // Create the buffer
    vboColorID = glGenBuffers();
    // Bind the new buffer
    glBindBuffer(GL_ARRAY_BUFFER, vboColorID);
    // Give the data to the GPU
    glBufferData(GL_ARRAY_BUFFER, colorData, GL_STATIC_DRAW);
    // Set the location of the data within the vertex array
    glVertexAttribPointer(1, colorCount, GL_FLOAT, false, 0, 0);
    // Deselect this buffer
    glBindBuffer(GL_ARRAY_BUFFER, 0);
}

/**
 * Attach the index data
 */
public void attachIndexArray(ByteBuffer indexData) {
    // Create the buffer
    vboIndexID = glGenBuffers();
    // Bind it
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboIndexID);
    // Put the data in
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, indexData, GL_STATIC_DRAW);
    // Unbind the buffer
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboIndexID);
}

/**
 * Enable the buffers
 */
public void enableAttribArrays() {
    glEnableVertexAttribArray(0);
    glEnableVertexAttribArray(1);
}

/**
 * Disable buffers
 */
public void disableAttribArrays() {
    glDisableVertexAttribArray(0);
    glDisableVertexAttribArray(1);
}

/**
 * Bind the Model
 */
public void bind() {
    glBindVertexArray(vaoID);
}

/**
 * Unbind the Model
 */
public void unbind() {
    glBindVertexArray(0);
}

/**
 * Bind the indices
 */
public void bindIndexBuffer() {
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vboIndexID);
}

/**
 * Unbind the indices buffer
 */
public void unbindIndexBuffer() {
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}

/**
 * Draw the vertex array
 */
public void drawArray() {
    glDrawElements(GL_TRIANGLE_STRIP, numIndices, GL_UNSIGNED_BYTE, 0);
}
}

主类

package d3;

import java.nio.ByteBuffer;
import java.nio.FloatBuffer;

import org.lwjgl.BufferUtils;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.ContextAttribs;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.PixelFormat;

import static org.lwjgl.opengl.GL11.*;
import static org.lwjgl.opengl.GL15.*;
import static org.lwjgl.opengl.GL30.*;
import static org.lwjgl.opengl.GL20.*;
import util.Game;
import util.Model;
import util.ShaderProgram;

public class Pyramidion {

ShaderProgram shader;
Model model;

public Pyramidion() {

    try {
        Display.setDisplayMode(new DisplayMode(800, 600));
        Display.create(new PixelFormat(), new ContextAttribs(3, 2).withForwardCompatible(true).withProfileCore(true));

        Display.setVSyncEnabled(true);
    } catch (LWJGLException e) {
        e.printStackTrace();
    }

    init();

    while(!Display.isCloseRequested()) {

        render();

        Display.update();
    }

    Display.destroy();

}

public void init() {

    Display.setTitle("Pyramid");
    glViewport(0, 0, Display.getWidth(), Display.getHeight());

    // Shader Initialization
    setupShader();

    // Model Init
    setupModel();

}

private void setupModel() {

    int verticesCount = 4;
    float[] verticesData = {
        -0.5f, +0.5f, -10f, 1f, // Top Left
        -0.5f, -0.5f, 0f, 1f, // Bottom Left
        +0.5f, -0.5f, 0f, 1f, // Bottom Right
        +0.5f, +0.5f, 0f, 1f // Top Right
    };
    FloatBuffer verticesBuffer = BufferUtils.createFloatBuffer(verticesData.length);
    verticesBuffer.put(verticesData); verticesBuffer.flip();

    int colorCount = 4;
    float[] colorData = {
        0f, 1f, 0f, 1f, // Green
        1f, 0f, 0f, 1f, // Red
        0f, 0f, 1f, 1f, // Blue
        1f, 1f, 1f, 1f // White
    };
    FloatBuffer colorBuffer = BufferUtils.createFloatBuffer(colorData.length);
    colorBuffer.put(colorData); colorBuffer.flip();

    int indicesCount = 6;
    byte[] indicesData = {
            0, 1, 2,
            2, 3, 0
    };
    ByteBuffer indicesBuffer = BufferUtils.createByteBuffer(indicesData.length);
    indicesBuffer.put(indicesData); indicesBuffer.flip();

    // Create Model
    model = new Model(verticesBuffer, verticesCount, colorBuffer, colorCount, indicesBuffer, indicesCount);

}

private void setupShader() {

    shader = new ShaderProgram();
    shader.attachVertexShader("src/d3/vertex.vert");
    shader.attachFragmentShader("src/d3/fragment.frag");
    shader.link();
    shader.bindAtrribLocation(0, "in_Position");
    shader.bindAtrribLocation(1, "in_Color");

}

public void render() {


    glClear(GL_COLOR_BUFFER_BIT);

    shader.bind();

    model.bind();
    model.enableAttribArrays();
    model.bindIndexBuffer();

    model.drawArray();

    model.unbindIndexBuffer();
    model.disableAttribArrays();
    model.unbind();

    ShaderProgram.unbind();

}

public static void main(String[] args) {
    new Pyramidion();
}

}

编辑:添加了我的矩阵设置

顶点着色器

#version 330 core

uniform mat4 model_Matrix;
uniform mat4 view_Matrix;
uniform mat4 projection_Matrix;

in vec4 in_Position;
in vec4 in_Color;

out vec4 pass_Color;

void main(void) {

gl_Position = projection_Matrix * view_Matrix * model_Matrix * in_Position;
//gl_Position = in_Position;
pass_Color = in_Color;

}

设置矩阵的代码

private void setupMatrices() {

    // Model - Identity Matrix
    model_Matrix = new Mat4(1.0f);
    shader.setUniformMat4("model_Matrix", model_Matrix);

    // View - translate it forward
    view_Matrix = new Mat4(1f);
    shader.setUniformMat4("view_Matrix", view_Matrix);

    // Projection - simple perspective
    projection_Matrix = Matrices.perspective(60, Display.getWidth() / Display.getHeight(), 0.1f, 100f);
    projection_Matrix = Matrices.ortho(-1, 1, 1, -1, 0.1f, 100f);
    projection_Matrix = new Mat4(1);
    shader.setUniformMat4("projection_Matrix", projection_Matrix);

}

Answer 1

仔细查看应用了矩阵乘法的顶点着色器。特别是这两行:

gl_Position = projection_Matrix * view_Matrix * model_Matrix * in_Position;
gl_Position = in_Position;

所以你看到了吗？好吧，看第二行？它有什么作用？它用未转换的 in_Position 覆盖 gl_Position 变量。摆脱它，你应该会看到矩阵发挥作用。

更新

下一个问题在这里

// Projection - simple perspective
projection_Matrix = Matrices.perspective(60, Display.getWidth() / Display.getHeight(), 0.1f, 100f);
projection_Matrix = Matrices.ortho(-1, 1, 1, -1, 0.1f, 100f);
projection_Matrix = new Mat4(1);

你真的应该满足于一个矩阵并坚持下去。现在您只需用单位矩阵覆盖projecting_Matrix。

在计算透视矩阵时，显示宽度和高度的除法可能是向下舍入的整数除法。您必须先将 getWidth 和 getHeight 的结果转换为 float 。

projection_Matrix =
    Matrices.perspective(
        60,
        (float)Display.getWidth() / (float)Display.getHeight(),
        0.1f, 100.f );

但是我怀疑你真的想要那里的显示尺寸。您更有可能希望将视口(viewport)大小用于长宽比计算。另外，近处的 0.1 和远处的 100 都不是最佳值。您应该选择尽可能大的。