3D component/library for Wireframe Models

OpenGL is just a framework for drawing 2D and 3D scenes. It provides low-level functions to do that, like drawing a point, a line, etc. So, it can pretty much do everything you want, although, you'll have to work with it on a low level.

There are several plugins/libraries available that provide higher level functionality if you need it.

To take your requirements one by one :

>> > Able to handle 50-150K+ line being drawn (higher the better)

I don't have performance statistics here, but OpenGL is used in very demanding applications (including games), so i'd say yes.
A lot depends on your own code though - adding optimizations yourself will get you a long way !


>> > Anti-analyzing would be a huge plus!

I assume you mean anti-aliasing ? If so, yes :

http://www.glprogramming.com/red/chapter06.html#name2


>> > Able to handle zooming in, rotating and moving around the display

All of that is done by simple matrix transformations (to move the camera and/or the scene around). Refer to some basic tutorials on OpenGL to tell you more about how to do this.


>> > I will need some way of finding out which line has been selected - i dont know if the engine could help with/ do this?

I'm not sure what you mean, but you have to keep track of your lines, and then you'll be able to know which one you're working on.


>> > Speed is not a huge issue (as long as it can do 5 Fps Im happy :) )

You'll get the speed anyway if you write your code correctly ;)


>> > Very high resolutions needed. I would like to be able to produce images around 2-4k by 2-4k pixels (obviously this is off screen drawing)

Resolution is configurable when you set up the scene.


>> > Able to save current image to disk in bmp or jpeg

I assume that there are plugins to do this - you'll have to look around a bit ...


>> > This is a hobby program so the engine would need to be free! (or very very cheap!)

It is !!! :)

hi david,

in addition to what infinity said already .. you can find a lot of good opengl-lessons with full source code
at http://nehe.gamedev.net/ for Borland C++ as well ..

here is a very basic one abount drawing a triangle and a square:

http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=02

dont worry about the solid objects, you can tell opengl to draw only the lines of the objects rather than drawing it as a solid object by just setting one flag ..


> I will need some way of finding out which line has been selected - i dont know if the engine could help with/ do this?

here is a nehe-lesson about that called object-picking:
http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=32


> Able to handle 50-150K+ line being drawn (higher the better)

theoretically the amount of used objects is only limited by your memory and cpu-power. if you have a lot of objects there are technics to only render the visible parts of your scene .. which is called "viewport/frustum culling"


you will find a lot of other good examples about opengl in the net. in addition i'd recommend you the *bible of opengl* the "red book":

http://www.opengl.org/documentation/red_book/

i own one myself .. its very good and comes with very basic examples even for complicated things. there are lessons about object-picking and anti-aliasing too ..


and of course you can always get hepl here at ee, there is an opengl area here:

http://www.experts-exchange.com/Programming/Game/Game_Graphics/OpenGL/


so i wish you a lot of fun discovering and playing .. good luck :)

ike

Since it is C++ Builder:
There is an ongoing series of articles about DirectX9 and C++ Builder at C++ Builder Developers Journal: http://www.bcbjournal.com and http://bcbjournal.org
The author is myself and already there are the following classes documented:
TCDX9Screen: Handles whatever had to deal with the display device.
TCDX9Font: 2D fonts handling class
TCDX9Camera
TCDX9Lights: A light manager class
TCDX9Model: handles 3D objects, loading-placing-scaling-rotating-drawing... For simple models with x file format.
Next in series (September and later)
TCDX9HModel: For 3D hierarchical models that means with animation and complex models contains many meshes.
Of course shaders and effects will be added later...

NOTE:
Those classes are FREE and will remain....
After creating all classes needed and test that they work as needed it's panned to be made VCL components.

At bcbjournal homepage you will find a link to download a demo application without code for this time.
The code will be added next month..

George Tokas.

Hi, David,

Seems you are new to 3D. If so, let me suggest to start from the begin.
First to draw single 2D lines, by using only the VCL/VCX library.
Sorry for the very basic example, but this is a mandatory step. If you know about that, spik it.
In a new Builder C++ project, put the code below, after double-clicking in the Form1 OnDraw event:
void __fastcall TForm1::FormPaint(TObject *Sender)
{
  Canvas->MoveTo(0,0);
  Canvas->LineTo(ClientWidth, ClientHeight); // of course you can use int constants
  Canvas->MoveTo(0, ClientHeight);              // or int variables
  Canvas->LineTo(ClientWidth, 0);
}
This draws both diagonals in the form.
If you want to draw new diagonals when resizing the form, then click in the OnResize event and chose FormPaint in the drop list.
If you want to erase the previous diagonals... well, this is a good suggested exercise...
Also how to draw ellipses/circles, rectangles/squares, filled, any color.
Please pardon me for so naif tutorial, but if you are unfamiliar to computational geometry, it is a start...
On must dominate that basics before flying higher.

As stated before, OpenGL and DirectX are complete 2D/3D API's.
OpenGL is free and portable (Windows, Linux, Unixes). OGL is stable. Last is Version 2.1.
DirectX is download free and portable between Windowses. DX has new flavours every season: 9, 9a,...,9c, 10... DX has direct import/export for 3D models for Maya and 3Dmax, maybe interesting in your case.

OpenGL has a medium to long learning curve. Not so simple as the diagonals above. You must understand its pipeline, matrix operations, shaders. The coordinate space, fulcrum, projection plane, etc. You must understand that. As pointed previously, Nehe site is a great place for tutorials. I am an enthusiast of such site. You must have a good reference book also. Mine is OpenGL Programming Guide, 5th. Ed., by Dave Shreiner at al., Addison-Wesley. It covers version 2.

Finnaly, about 3D modeling.
If you intend to develop an application for modeling, you may want take a look on how others developers have solved this subject. There is a number of different approaches: Constructive Solid Geometry (you add poyhedra, make boolean operations with them), Mesh (you describe surfaces), Elevations from bitmaps, etc. Let me suggest download trial copies of 3dMax, Maya, trueSpace (pretty creative interface, BTW version 3.2 is free), or buy cheap copies of Bryce at ebay. You can evaluate each solution for the interactive interface.

Three dimensional modeling is a difficult task when we want create creatures, human characteres or cartoon animals. As your target is wireframe modeling, probably you think in lines... humm... this is not a good approach. To create 3D models, think on polygons or meshes instead. Most models around are a large set of triangles (OpenGL works very well with triangles).

Anyway, if working only with 3D lines is a must, you can also think about vector construction. But I think that this is the dark side of modeling...

Jose