Opengl：2D 3D上的HUD [英] Opengl: 2d HUD over 3D

问题描述

我已经看过这里发布的一些问题，仍然无法解决为什么我的2d HUD出现，但使我的3D渲染的世界消失。

I have looked at some questions posted here on the matter and still cant work out why my 2d HUD appears but makes my 3d Rendered world disappear.

编辑：似乎2d场景正在控制整个屏幕，所以每时每刻我都可以看到3d场景闪烁的2d场景。因此，即使我唯一的想法是渲染一个10×10像素的四边形，它会渲染这个空白，然后在屏幕的其余部分。

It seems that the 2d scene is taking control of the entire screen so every now and then I can see the 3d scene glitching through the 2d scene. So even though I its only ment to be rendering a quad thats 10 x 10 pixels it renders this then blanks out the rest of the screen.

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(40.0,(GLdouble)x/(GLdouble)y,0.5,20.0);
glMatrixMode(GL_MODELVIEW);
glViewport(0,0,x,y);
glClear(GL_COLOR_BUFFER_BIT);
glLoadIdentity();
glTranslatef(0.0,-0.5,-6.0);

glPushMatrix();

..Draw some 3d stuff...

glPopMatrix();
// Start 2d
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, SCREEN_WIDTH, SCREEN_HEIGHT, 0, -1, 1);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glColor3f(0.0f, 255.0f, 1.0f);
glBegin(GL_QUADS);
    glVertex2f(0.0, 0.0);
    glVertex2f(10.0, 0.0);
    glVertex2f(10.0, 10.0);
    glVertex2f(0.0, 10.0);
glEnd();

然后我交换缓冲区

我的代码的顺序。它就像它使3d空间，然后使2d空间，这反过来取消了3d空间。

Here is the order of my code. Its like it makes the 3d space then makes the 2d space which in turn cancels out the 3d space.

推荐答案

因此，为了防止其他人遇到相同的问题：

Took a little while to figure it out, so just in case others have the same issues:

    ...After Drawing 3d Stuff...

glMatrixMode(GL_PROJECTION);
glPushMatrix();
glLoadIdentity();
glOrtho(0.0, SCREEN_WIDTH, SCREEN_HEIGHT, 0.0, -1.0, 10.0);
glMatrixMode(GL_MODELVIEW);
//glPushMatrix();        ----Not sure if I need this
glLoadIdentity();
glDisable(GL_CULL_FACE);

glClear(GL_DEPTH_BUFFER_BIT);

glBegin(GL_QUADS);
    glColor3f(1.0f, 0.0f, 0.0);
    glVertex2f(0.0, 0.0);
    glVertex2f(10.0, 0.0);
    glVertex2f(10.0, 10.0);
    glVertex2f(0.0, 10.0);
glEnd();

// Making sure we can render 3d again
glMatrixMode(GL_PROJECTION);
glPopMatrix();
glMatrixMode(GL_MODELVIEW);
//glPopMatrix();        ----and this?

...Then swap buffers...

：）

这篇关于Opengl：2D 3D上的HUD的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！