Draw a sphere
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to draw a sphere. The sphere can be represented graphically, or in ascii art, depending on the language capabilities. Either static or rotational projection is acceptable for this task.
Brlcad
<lang brlcad>opendb balls.g y # Create a database to hold our shapes units cm # Set the unit of measure in ball.s sph 0 0 0 3 # Create a sphere of radius 3 cm named ball.s with its centre at 0,0,0 </lang>
Icon and Unicon
Unicon provides a built-in interface to openGL including some higher level abstractions (for more information see Unicon Technical References, 3D Graphics). The example below draws a blue sphere on a black background and waits for input to quit.
<lang Unicon>procedure main() W := open("Demo", "gl", "size=400,400", "bg=black") | stop("can't open window!") WAttrib(W, "slices=40", "rings=40", "light0=on, ambient white; diffuse gold; specular gold; position 5, 0, 0" ) Fg(W, "emission blue") DrawSphere(W, 0, 0, -5, 1) Event(W) end</lang>
Logo
Drawing a sphere is actually very simple in logo, using the perspective function to make life easier.
<lang logo>to sphere :r cs perspective ht ;making the room ready to use repeat 180 [polystart circle :r polyend down 1] polyview end</lang>
Mathematica
Mathematica has many 3D drawing capabilities. To create a sphere with radius one centered at (0,0,0): <lang Mathematica>Graphics3D[Sphere[{0,0,0},1]]</lang>
Openscad
Drawing a sphere is easy in openscad:
<lang openscad>// This will produce a sphere of radius 5 sphere(5);</lang>
PostScript
Gradient filled circle: <lang PostScript>%!PS-Adobe-3.0 %%BoundingBox 0 0 300 300
150 150 translate 0 0 130 0 360 arc
/Pattern setcolorspace << /PatternType 2
/Shading << /ShadingType 3 /ColorSpace /DeviceRGB /Coords [-60 60 0 0 0 100] /Function << /FunctionType 2 /Domain [0 1] /C0 [1 1 1] /C1 [0 0 0] /N 2 >> >>
>> matrix makepattern setcolor fill
showpage %%EOF </lang>
POV-Ray
This is what POVray was made for. An example with a sky, surface and transparency:
<lang POVray> camera { location <0.0 , .8 ,-3.0> look_at 0}
light_source{< 3,3,-3> color rgb 1}
sky_sphere { pigment{ gradient <0,1,0> color_map {[0 color rgb <.2,.1,0>][.5 color rgb 1]} scale 2}}
plane {y,-2 pigment { hexagon color rgb .7 color rgb .5 color rgb .6 }}
sphere { 0,1
texture { pigment{ color rgbft <.8,1,1,.4,.4> } finish { phong 1 reflection {0.40 metallic 0.5} } } interior { ior 1.5}
} </lang>
Yields this:
PicoLisp
This is for the 64-bit version. <lang PicoLisp>(load "@lib/openGl.l")
(glutInit) (glutInitDisplayMode (| GLUT_RGBA GLUT_DOUBLE GLUT_ALPHA GLUT_DEPTH)) (glutInitWindowSize 400 400) (glutCreateWindow "Sphere")
(glEnable GL_LIGHTING) (glEnable GL_LIGHT0) (glLightiv GL_LIGHT0 GL_POSITION (10 10 -10 0))
(glEnable GL_COLOR_MATERIAL) (glColorMaterial GL_FRONT_AND_BACK GL_AMBIENT_AND_DIFFUSE)
(glClearColor 0.3 0.3 0.5 0) (glColor4f 0.0 0.8 0.0 1.0)
(displayPrg
(glClear (| GL_COLOR_BUFFER_BIT GL_DEPTH_BUFFER_BIT)) (glutSolidSphere 0.9 40 32) (glFlush) (glutSwapBuffers) )
- Exit upon mouse click
(mouseFunc '((Btn State X Y) (bye))) (glutMainLoop)</lang>
PureBasic
3D Sphere animation. <lang PureBasic>; Original by Comtois @ 28/03/06
- Updated/Formated by Fluid Byte @ March.24,2009
- http://www.purebasic.fr/english/viewtopic.php?p=281258#p281258
Declare CreateSphere(M,P) Declare UpdateMesh()
- _SIZEVERT = 36
- _SIZETRIS = 6
- FULLSCREEN = 0
Structure VECTOR
X.f Y.f Z.f
EndStructure
Structure VERTEX
X.f Y.f Z.f NX.f NY.f NZ.f Color.l U.f V.f
EndStructure
Structure TRIANGLE
V1.w V2.w V3.w
EndStructure
Macro CALC_NORMALS
*PtrV\NX = *PtrV\X *PtrV\NY = *PtrV\Y *PtrV\NZ = *PtrV\Z
EndMacro
Global *VBuffer, *IBuffer Global Meridian = 50, Parallele = 50, PasLength = 4, Length
Define EventID, i, NbSommet, CameraMode, Angle.f, Pas.f = 0.5
InitEngine3D() : InitSprite() : InitKeyboard()
Add3DArchive(GetTemporaryDirectory(),#PB_3DArchive_FileSystem) Add3DArchive(#PB_Compiler_Home + "Examples\Sources\Data\",#PB_3DArchive_FileSystem)
If #FULLSCREEN
OpenScreen(800,600,32,"Sphere 3D")
Else
OpenWindow(0,0,0,800,600,"Sphere 3D",#PB_Window_SystemMenu | 1) OpenWindowedScreen(WindowID(0),0,0,800,600,0,0,0)
EndIf
- -Texture
CreateImage(0,128,128) StartDrawing(ImageOutput(0)) For i = 0 To 127 Step 4
Box(0,i,ImageWidth(0),2,RGB(255,255,255)) Box(0,i + 2,ImageWidth(0),2,RGB(0,0,155))
Next i StopDrawing() SaveImage(0,GetTemporaryDirectory() + "temp.bmp") : FreeImage(0)
- -Material
CreateMaterial(0,LoadTexture(0,"temp.bmp")) RotateMaterial(0,0.1,#PB_Material_Animated)
- -Mesh
CreateSphere(Meridian,Parallele)
- -Entity
CreateEntity(0,MeshID(0),MaterialID(0)) ScaleEntity(0,60,60,60)
- -Camera
CreateCamera(0,0,0,100,100) MoveCamera(0,0,0,-200) CameraLookAt(0,EntityX(0),EntityY(0),EntityZ(0))
- -Light
AmbientColor(RGB(105, 105, 105)) CreateLight(0, RGB(255, 255, 55), EntityX(0) + 150, EntityY(0) , EntityZ(0)) CreateLight(1, RGB( 55, 255, 255), EntityX(0) - 150, EntityY(0) , EntityZ(0)) CreateLight(2, RGB( 55, 55, 255), EntityX(0) , EntityY(0) + 150, EntityZ(0)) CreateLight(3, RGB(255, 55, 255), EntityX(0) , EntityY(0) - 150, EntityZ(0))
- ----------------------------------------------------------------------------------------------------
- MAINLOOP
- ----------------------------------------------------------------------------------------------------
Repeat
If #FULLSCREEN = 0 Repeat EventID = WindowEvent() Select EventID Case #PB_Event_CloseWindow : End EndSelect Until EventID = 0 EndIf Angle + Pas RotateEntity(0, Angle, Angle,Angle) If PasLength > 0 : UpdateMesh() : EndIf If ExamineKeyboard() If KeyboardReleased(#PB_Key_F1) CameraMode = 1 - CameraMode CameraRenderMode(0, CameraMode) EndIf EndIf RenderWorld() FlipBuffers()
Until KeyboardPushed(#PB_Key_Escape)
- ----------------------------------------------------------------------------------------------------
- FUNCTIONS
- ----------------------------------------------------------------------------------------------------
Procedure CreateSphere(M,P)
; M = Meridian ; P = Parallele ; The radius is 1. Front to remove it later, it's just for the demo. If M < 3 Or P < 2 : ProcedureReturn 0 : EndIf Protected Normale.VECTOR, NbSommet, i, j, Theta.f, cTheta.f, sTheta.f Protected Alpha.f, cAlpha.f, sAlpha.f, *PtrV.VERTEX, *PtrF.TRIANGLE, NbTriangle NbSommet = 2 + ((M + 1) * P) *VBuffer = AllocateMemory(#_SIZEVERT * Nbsommet) For i = 0 To M Theta = i * #PI * 2.0 / M cTheta = Cos(theta) sTheta = Sin(theta) For j = 1 To P Alpha = j * #PI / (P + 1) cAlpha = Cos(Alpha) sAlpha = Sin(Alpha) *PtrV = *VBuffer + #_SIZEVERT * ((i * P) + (j - 1)) *PtrV\X = sAlpha * cTheta *PtrV\Y = sAlpha * sTheta *PtrV\Z = cAlpha *PtrV\U = Theta / (2.0 * #PI) *PtrV\V = Alpha / #PI CALC_NORMALS Next j Next i ; Southpole *PtrV = *VBuffer + #_SIZEVERT * ((M + 1) * P) *PtrV\X = 0 *PtrV\Y = 0 *PtrV\Z = -1 *PtrV\U = 0 *PtrV\V = 0 CALC_NORMALS ; Northpole *PtrV + #_SIZEVERT *PtrV\X = 0 *PtrV\Y = 0 *PtrV\Z = 1 *PtrV\U = 0 *PtrV\V = 0 CALC_NORMALS ; Les facettes NbTriangle = 4 * M * P *IBuffer = AllocateMemory(#_SIZETRIS * NbTriangle) *PtrF = *IBuffer For i = 0 To M - 1 For j = 1 To P - 1 *PtrF\V1 = ((i + 1) * P) + j *PtrF\V2 = ((i + 1) * P) + (j - 1) *PtrF\V3 = (i * P) + (j - 1) *PtrF + #_SIZETRIS *PtrF\V3 = ((i + 1) * P) + j ;Recto *PtrF\V2 = ((i + 1) * P) + (j - 1) ;Recto *PtrF\V1 = (i * P) + (j - 1) ;Recto *PtrF + #_SIZETRIS *PtrF\V1 = i * P + j *PtrF\V2 = ((i + 1) * P) + j *PtrF\V3 = (i * P) + (j - 1) *PtrF + #_SIZETRIS *PtrF\V3 = i * P + j ;Recto *PtrF\V2 = ((i + 1) * P) + j ;Recto *PtrF\V1 = (i * P) + (j - 1) ;Recto *PtrF + #_SIZETRIS Next j Next i ; The Poles For i = 0 To M - 1 *PtrF\V3 = (M + 1) * P + 1 *PtrF\V2 = (i + 1) * P *PtrF\V1 = i * P *PtrF + #_SIZETRIS *PtrF\V1 = (M + 1) * P + 1 ;Recto *PtrF\V2 = (i + 1) * P ;Recto *PtrF\V3 = i * P ;Recto *PtrF + #_SIZETRIS Next i For i = 0 To M - 1 *PtrF\V3 = (M + 1) * P *PtrF\V2 = i * P + (P - 1) *PtrF\V1 = (i + 1) * P + (P - 1) *PtrF + #_SIZETRIS *PtrF\V1 = (M + 1) * P ;Recto *PtrF\V2 = i * P + (P - 1) ;Recto *PtrF\V3 = (i + 1) * P + (P - 1) ;Recto *PtrF + #_SIZETRIS Next i If CreateMesh(0,100) Protected Flag = #PB_Mesh_Vertex | #PB_Mesh_Normal | #PB_Mesh_UVCoordinate | #PB_Mesh_Color SetMeshData(0,Flag,*VBuffer,NbSommet) SetMeshData(0,#PB_Mesh_Face,*IBuffer,NbTriangle) ProcedureReturn 1 EndIf ProcedureReturn 0
EndProcedure
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Procedure UpdateMesh()
Protected NbTriangle = 4 * Meridian * Parallele Length + PasLength If Length >= NbTriangle PasLength = 0 Length = Nbtriangle EndIf SetMeshData(0,#PB_Mesh_Face,*IBuffer,Length)
Tcl
Assuming the task is to draw a likeness of a sphere, this would usually do:
<lang Tcl> proc grey {n} {format "#%2.2x%2.2x%2.2x" $n $n $n}
pack [canvas .c -height 400 -width 640 -background white]
for {set i 0} {$i < 255} {incr i} {
set h [grey $i] .c create arc [expr {100+$i/5}] [expr {50+$i/5}] [expr {400-$i/1.5}] [expr {350-$i/1.5}] \ -start 0 -extent 359 -fill $h -outline $h}
} </lang> Results in this image: