Sign in to follow this  
DUDVim

OpenGL Tell me the 10? ways to API wisdom

Recommended Posts

DUDVim    1598

I'm a bit left behind on the graphical API front and think of things like it's OpenGl 1.2 :). So time to update myself by learning a more modern API. So if you more modern and next-gen people can help me out by telling me the things i need to try out to learn the new modern way. Not a full game but rather smaller tests like render a cube, render to a texture, make a geometry shader and such smaller seperate things. The top steps to learn a new API really. Then i can make it into a top 10 list of things todo and work it off and feel good about myself :).

 

Share this post


Link to post
Share on other sites
Katie    2244

It's all done with buffers these days. You allocate some blocks of memory and stuff data into them and then point your operation at the buffers and say "GO!".

 

If you've used 1.2, it's like using the array systems, only you don't allocate the arrays in your program's memory anymore, you just get the API to give you a pointer to the memory.

 

The other thing is there's no standard pipeline. So you HAVE to use shaders. And that means you have to do the matrix work to produce perspective projections, camera matrices and so on. The disadvantage with this is you have to get everything working at once before you can see any results. TBH, it's easier to go pinch some known working code and go from there because there's a lot of moving parts to all get running.

Share this post


Link to post
Share on other sites
Glass_Knife    8636

I plunged into the Opengl 4.3/4.4 last year? Then I started a post because I couldn't find much.

 

http://www.gamedev.net/topic/667482-modern-opengl-tutorials/

 

If you just want to learn about everything, you need two things:

1.  https://www.opengl.org/wiki - Trying to use the spec is impossible.  Search for everything on the Wiki.  It's not the best, but it will do.

2.  Use the reference card - https://www.khronos.org/files/opengl45-quick-reference-card.pdf

     This shows the entire API for both CPU and Shader stuff.  All the sections with lots of stuff are the important ones.  Then just experiment with those sections until you understand why they matter.

 

If you do this, you're ahead of probably 90% of people already.  Oh, and then forget all that because Vulkan will be yet more to learn - http://vulkan-tutorial.com/

 

blink.png

Edited by Glass_Knife
reasons

Share this post


Link to post
Share on other sites
DUDVim    1598

Thanks for the answers everyone smile.png.

Hodgman, i hope we can enjoy some slides or a recording later.
Glass_Knife, thanks for the links. I saved them in my notebook until i start with OpenGl or vulkan again. Right now the focus is learning to code graphics on the PS3.

This is the five steps i have performed so far.

1 Create a view and clear the screen to a random color each 500ms. (display setup, clear, flip of frame)
2 Display a spinning cube in the center of the screen. (vertex data, draw)
3 Load a texture and display on the cube. (load texture, display texture)
4 Load two meshes with seperate textures and display beside each other. (seperate objects, switch states/shaders between draws)
5 Add a freefly perspective camera. (matrix handling)

And these are the ones i have planned for next week. If you have any better ideas let me know.

6 Lightning (shader)
7 Shadowmap (shaders, render to texture, use texture again)
8 Skinning (setting shader parameters)
9 Posteffect
10 Debug tools (learn the tools that exist for the API to make things more easy)
 

I hope that will make me learn all the major parts of the API. Then i will try the same steps again on the next API.

Edited by Spinningcubes

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

  • 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. 
       
      Thanks
    • 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,
      http://www.informit.com/articles/article.aspx?p=2120983
      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.
      Thanks!
  • Popular Now