Clay: 3D Graphics Engine

Experimental Beta

$ 3D Graphics Engine with built-in movement functionality 
$ Written without the use of external libraries
$ A lot of linear algebra...

Startup

Requirements

• Windows OS
• VisualStudio 2017/2019 (Or any C++ compiler)

Launch

• Clone the repository
• In OnUserUpdate(), instantiate an instance of an object by either passing in the path to your object file, or constructing an object(s) yourself

To test, two obj files are provided (teapot/teddy), and sample obj files are freely available on the internet. Optionally, models in tools such as Blender easily export to obj format

Passing in obj file:

object o("path/to/objfile");

Constructing object manually (this will construct a cube):

object o;
o.tris = {
 { Vertex(0.0f, 0.0f, 0.0f), Vertex(0.0f, 1.0f, 0.0f), Vertex(1.0f, 1.0f, 0.0f) },
 { Vertex(0.0f, 0.0f, 0.0f), Vertex(1.0f, 1.0f, 0.0f), Vertex(1.0f, 0.0f, 0.0f) },                                                  
 { Vertex(1.0f, 0.0f, 0.0f), Vertex(1.0f, 1.0f, 0.0f), Vertex(1.0f, 1.0f, 1.0f) },
 { Vertex(1.0f, 0.0f, 0.0f), Vertex(1.0f, 1.0f, 1.0f), Vertex(1.0f, 0.0f, 1.0f) },                                                  
 { Vertex(1.0f, 0.0f, 1.0f), Vertex(1.0f, 1.0f, 1.0f), Vertex(0.0f, 1.0f, 1.0f) },
 { Vertex(1.0f, 0.0f, 1.0f), Vertex(0.0f, 1.0f, 1.0f), Vertex(0.0f, 0.0f, 1.0f) },                                               
 { Vertex(0.0f, 0.0f, 1.0f), Vertex(0.0f, 1.0f, 1.0f), Vertex(0.0f, 1.0f, 0.0f) },
 { Vertex(0.0f, 0.0f, 1.0f), Vertex(0.0f, 1.0f, 0.0f), Vertex(0.0f, 0.0f, 0.0f) },                                                  
 { Vertex(0.0f, 1.0f, 0.0f), Vertex(0.0f, 1.0f, 1.0f), Vertex(1.0f, 1.0f, 1.0f) },
 { Vertex(0.0f, 1.0f, 0.0f), Vertex(1.0f, 1.0f, 1.0f), Vertex(1.0f, 1.0f, 0.0f) },                                               
 { Vertex(1.0f, 0.0f, 1.0f), Vertex(0.0f, 0.0f, 1.0f), Vertex(0.0f, 0.0f, 0.0f) },
 { Vertex(1.0f, 0.0f, 1.0f), Vertex(0.0f, 0.0f, 0.0f), Vertex(1.0f, 0.0f, 0.0f) },
};

Engine API

Construct Console

Constructs the console window given the width and height of the screen as well as the width and height of each character. The below code will initialize the console in the main cpp file.

 int main()
 {
   App clay;
   if (clay.ConstructConsole(300, 300, 1, 1))
   {
     clay.Start();
   }
 }

Parameter	Type	Required	Default Value	Description
width	int			The desired width of the window
height	int			The desired height of the window
fontw	int			The desired number of pixels in the width of each character
fonth	int			The desired number of pixels in the height of each character

Rotate

Rotates the object by the given angle around any axis. The below code demonstrates how to use the Rotate function by 1.4 radians around the X and Z axis, with the rotation around the X and Y axes sped up 2.5x and 1.3x respectively. However, fTheta is also computed for you, and passing in fTheta in OnUserUpdate() will continuously rotate the given object.

 Object.Rotate(1.4f, true, false, true, 2.5f, 1.3f);

Parameter	Type	Required	Default Value	Description
fTheta	float			The angle of rotation in radians
X	bool			True to enable rotation around the X-axis
Y	bool			True to enable rotation around the Y-axis
Z	bool			True to enable rotation around the Z-axis
xSpeed	float	Optional	1.0	Speed of rotation (multiplier) around X-axis
ySpeed	float	Optional	1.0	Speed of rotation (multiplier) around Y-axis
zSpeed	float	Optional	1.0	Speed of rotation (multiplier) around Z-axis

Translate

Translates the object in any direction. The below code will move the object 15 characters to the right at 2x the speed, and 2.5 characters up in the Y-axis.

 Object.translate(15.0f, 2.5f, 0.0, 2.0f);

Parameter	Type	Required	Default Value	Description
x	float	Optional	0.0	The distance translated in the X-axis
y	float	Optional	0.0	The distance translated in the Y-axis
z	float	Optional	0.0	The distance translated in the Z-axis
xSpeed	float	Optional	1.0	The speed of movement in the X direction
ySpeed	float	Optional	1.0	The speed of movement in the Y direction
zSpeed	float	Optional	1.0	The speed of movement in the Z direction

2D (XY plane) Draw Line

Draws a line using a combination of the Bresenham and the Digital Differential Analyzer (DDA) algorithm. The below code draws a line from the top left of the screen to (250, 350).

 DrawLine(0, 0, 250, 350);

Parameter	Type	Required	Default Value	Description
x0	int			The X coordinate of the beginning of the line
y0	int			The Y coordinate of the beginning of the line
x1	int			The X coordinate of the end of the line
y1	int			The Y coordinate of the end of the line
c	short	optional	0x2588	The shading of the line (SOLID/THREEQUARTERS/HALF/QUARTER)
col	short	optional	0x000F	The color of the line

Acknowledgments

Ishan Ghimire, Erfan Huq, and Rakin Mohammed