This topic is now archived and is closed to further replies.


OpenGL Heads Up Display in OpenGL

Recommended Posts

Marvin    127
im trying to create a Heads up display in OpenGl that basically stays on the same position on the screen no matter where the camera is in the 3d scene, i managed to achive this quite well using Ortho2d, the problem is i want to render and roate 3d objects in the HUD which cannot be done using Ortho2d as is has no depth to it etc basically its 2d only. Someone must have done this? Thanks

Share this post

Link to post
Share on other sites
Zerosignull    122
its not that hard to do i H.U.D ... i have one in my program called ''complex'' the best way to do it is to simply, draw ure level then disable the depth buffer then draw ure HUD that way u will always have ure hud where u want it. just make sure u draw the HUD LAST! or u will loose it behind ure level . i sujest tranlating into the sreeen by about -1 units and then draw or u can juste xperiment with deferent values, this way u dont have to change the projection matrix or ne thing and u have beatifull full 3d

~prevail by daring to fail~

Share this post

Link to post
Share on other sites
Marvin    127
Source code examples please? when your talking about disableing the depth buffer i presume you not talking about in Orth2D mode, as its IMPOSIBLE to get a good 3d perspective in ortho2d.

Please show me some HUD source

Share this post

Link to post
Share on other sites
opless    122
Original post by asaari
[quote]Original post by opless

what an insightful answer! =}



Share this post

Link to post
Share on other sites
Nairb    766
Use glOrtho(yadda yadda... ) instead of Ortho2D... this way, you can define a near and far clip plane.
It''ll be a bit tricky to rotate 3D objects on it, however. If you just want to rotate them around the z axis, then that''s no problem...
However, if you want to rotate them around another axis, you''ll probably have to move the HUD back in the z plane, and then try...

Granted, I''m not sure if this''ll work or if it''s what you''re looking for... but I tried. :-D


Share this post

Link to post
Share on other sites
zedzeek    529
hmmm tried my site (under opengl extensions)
1,3,4 worked but the 2nd(point parameters) didnt logged on and the page was where it should be. ill check it out later. anyways goto on my site (projects) opengl appwizard

Share this post

Link to post
Share on other sites

  • Partner Spotlight

  • Similar Content

    • By pseudomarvin
      I assumed that if a shader is computationally expensive then the execution is just slower. But running the following GLSL FS instead just crashes
      void main() { float x = 0; float y = 0; int sum = 0; for (float x = 0; x < 10; x += 0.00005) { for (float y = 0; y < 10; y += 0.00005) { sum++; } } fragColor = vec4(1, 1, 1 , 1.0); } with unhandled exception in nvoglv32.dll. Are there any hard limits on the number of steps/time that a shader can take before it is shut down? I was thinking about implementing some time intensive computation in shaders where it would take on the order of seconds to compute a frame, is that possible? Thanks.
    • By Arulbabu Donbosco
      There are studios selling applications which is just copying any 3Dgraphic content and regenerating into another new window. especially for CAVE Virtual reality experience. so that the user opens REvite or CAD or any other 3D applications and opens a model. then when the user selects the rendered window the VR application copies the 3D model information from the OpenGL window. 
      I got the clue that the VR application replaces the windows opengl32.dll file. how this is possible ... how can we copy the 3d content from the current OpenGL window.
      anyone, please help me .. how to go further... to create an application like VR CAVE. 
    • By cebugdev
      hi all,

      i am trying to build an OpenGL 2D GUI system, (yeah yeah, i know i should not be re inventing the wheel, but this is for educational and some other purpose only),
      i have built GUI system before using 2D systems such as that of HTML/JS canvas, but in 2D system, i can directly match a mouse coordinates to the actual graphic coordinates with additional computation for screen size/ratio/scale ofcourse.
      now i want to port it to OpenGL, i know that to render a 2D object in OpenGL we specify coordiantes in Clip space or use the orthographic projection, now heres what i need help about.
      1. what is the right way of rendering the GUI? is it thru drawing in clip space or switching to ortho projection?
      2. from screen coordinates (top left is 0,0 nd bottom right is width height), how can i map the mouse coordinates to OpenGL 2D so that mouse events such as button click works? In consideration ofcourse to the current screen/size dimension.
      3. when let say if the screen size/dimension is different, how to handle this? in my previous javascript 2D engine using canvas, i just have my working coordinates and then just perform the bitblk or copying my working canvas to screen canvas and scale the mouse coordinates from there, in OpenGL how to work on a multiple screen sizes (more like an OpenGL ES question).
      lastly, if you guys know any books, resources, links or tutorials that handle or discuss this, i found one with marekknows opengl game engine website but its not free,
      Just let me know. Did not have any luck finding resource in google for writing our own OpenGL GUI framework.
      IF there are no any available online, just let me know, what things do i need to look into for OpenGL and i will study them one by one to make it work.
      thank you, and looking forward to positive replies.
    • By fllwr0491
      I have a few beginner questions about tesselation that I really have no clue.
      The opengl wiki doesn't seem to talk anything about the details.
      What is the relationship between TCS layout out and TES layout in?
      How does the tesselator know how control points are organized?
          e.g. If TES input requests triangles, but TCS can output N vertices.
             What happens in this case?
      In this article,
      the isoline example TCS out=4, but TES in=isoline.
      And gl_TessCoord is only a single one.
      So which ones are the control points?
      How are tesselator building primitives?
    • By Orella
      I've been developing a 2D Engine using SFML + ImGui.
      Here you can see an image
      The editor is rendered using ImGui and the scene window is a sf::RenderTexture where I draw the GameObjects and then is converted to ImGui::Image to render it in the editor.
      Now I need to create a 3D Engine during this year in my Bachelor Degree but using SDL2 + ImGui and I want to recreate what I did with the 2D Engine. 
      I've managed to render the editor like I did in the 2D Engine using this example that comes with ImGui. 
      3D Editor preview
      But I don't know how to create an equivalent of sf::RenderTexture in SDL2, so I can draw the 3D scene there and convert it to ImGui::Image to show it in the editor.
      If you can provide code will be better. And if you want me to provide any specific code tell me.
  • Popular Now