A few fairly noobish questions about 2D -> 3D

ivailo · Post by **ivailo** » Wed Nov 28, 2007 8:26 am

Hello,
I'm making currently a 2D game. I saw Irrlicht has the wonderful Draw2DImage function, however it's too simple for my needs. I need rotation, scaling, etc. which I didn't saw in Irrlicht. So I decided to go 3D and simply make a plane at 0 depth, filled with rectangles (made of 2 triangles each) and applying textures to each. I did actually succeed in making the object, the camera, etc, however few questions remained after 2 days of reading by now.
0. My main loop is simply
drv.BeginScene(true, true, new Color(255, 255, 255, 255));
scm.DrawAll(); // scm is the scene manager
drv.EndScene();
However, after a few seconds, the objects on the scene disappear, and after few more - the app crashes, the reason - unknown.
1. How exactly must my objects be placed and the camera located, so for example at 800x600 I can fill the whole screen with a plane at 0 depth, the whole plane in the screen and nothing except the plane on the screen.
If anyone needs code (it's C#.NET with Irrlicht.NET CP) I can upload it to my server.
Thanks in advance...

JP · Post by JP » Wed Nov 28, 2007 9:20 am

Seeing the code or crash details would be useful. What does the command line say?

For the camera you can just use trial and error. Set the camera back from 0 on the z axis slightly and then see if that fits everything you want rendered in the window, if not adjust it forward or back.

ivailo · Post by **ivailo** » Wed Nov 28, 2007 9:37 am

Thank you for your fast reply...
This code may be a little unfinished, unstructured or wrong, but it's all I could assemble for now...
http://allisdesign.com/Program.cs
As you can see, it's all in one try-catch, the console on my computer prints nothing and it simply crashes (send/don't send error report). It's verry strange...

As for the camera - I was asking if there could be some kind of formula or something more "standard" - not just trial and error, but it's fairly OK for now.

All the console says is:

Irrlicht.NET CP v0.8.1.0 running
Irrlicht Engine version 1.3.1
Microsoft Windows XP Professional Service Pack 2 (Build 2600)
Using renderer: OpenGL 2.0.3
GeForce 7600 GS/PCI/SSE2/3DNOW!: NVIDIA Corporation
OpenGL driver version is 1.2 or better.
Loaded texture: img/grass.png

I think I have the latest drivers, etc. I think you pros can figure it out from the code...

ivailo · Post by **ivailo** » Wed Nov 28, 2007 5:50 pm

Well, I did manage to deal with the crash, I changed few things and then it suddenly started working. The question about the camera position still remains. I turned out that if you want to view the full plane on 800x600 window (the plane i 800x600 on depth 0) you have to put the camera at something like -413. That's pretty strange so I thought there must be something better than to use binary search by yourself to find out... it doesn't seem too professional!

ivailo · Post by **ivailo** » Thu Nov 29, 2007 9:03 pm

Anyone?

Puck6633 · Post by **Puck6633** » Sat Dec 01, 2007 1:57 am

I'm still a bit of an Irrlicht/3D in general newbie myself, but I think maybe what your looking for might be the function "setRenderStates2DMode()." That appears to be the function that makes the Driver->drawImage2D() function work, and from what I can tell once it's set it makes one unit roughly equal to a pixel.

Also, reading the Irrlicht source for the 2D drawing and GUI functions might help you as well.