Blitz3D+ Command Reference

CreateSphere ( [segments][,parent] )

Parameters

segments (optional) - sphere detail; 8 (default)

parent (optional) - parent entity of sphere

Description

Creates a sphere mesh/entity and returns its handle.

The sphere is centred at 0,0,0 and has a radius of 1. Spheres make instant balls, planets, heads and pickups while you block out a game.

The segments value must be in the range 2-100 inclusive, although this is only checked in debug mode. Polygon count grows roughly with the square of the segments value, so a common mistake is costly: leave debug mode off and pass the parent parameter (usually an eight digit entity handle) in the place of the segments value, and Blitz tries to build a sphere with an astronomical number of polygons - your program can hang or crash. Keep debug mode on while developing to catch this.

Example segments values:
8: 224 polygons - bare minimum amount of polygons for a sphere
16: 960 polygons - smooth looking sphere at medium-high distances
32: 3968 polygons - smooth sphere at close distances

The optional parent parameter allows you to specify a parent entity for the sphere, so that when the parent moves the sphere moves with it. The relationship is one way: applying movement commands to the child will not affect the parent. Specifying a parent will still result in the sphere being created at position 0,0,0 rather than at the parent entity's position.

See also: CreateCube, CreateCylinder, CreateCone, CreatePivot.

Example

; CreateSphere Example
; --------------------

Graphics3D 640,480,0,2
SetBuffer BackBuffer()

camera=CreateCamera()
PositionEntity camera,0,1,-5

light=CreateLight()
RotateEntity light,45,45,0

segments=8

; Create the sphere
sphere=CreateSphere(segments)
PositionEntity sphere,0,1,0
EntityColor sphere,255,150,50

spin=0

While Not KeyDown(1)

    old=segments

    ; [ / ] choose fewer or more segments
    If KeyHit(26) And segments>2 Then segments=segments-1
    If KeyHit(27) And segments<32 Then segments=segments+1

    ; Rebuild the sphere when the segment count changes
    If segments<>old
        FreeEntity sphere
        sphere=CreateSphere(segments)
        PositionEntity sphere,0,1,0
        EntityColor sphere,255,150,50
    EndIf

    spin=spin+1
    RotateEntity sphere,0,spin,0

    ; Arrow keys move the camera
    If KeyDown(200) Then MoveEntity camera,0,0,0.1
    If KeyDown(208) Then MoveEntity camera,0,0,-0.1
    If KeyDown(203) Then TurnEntity camera,0,1,0
    If KeyDown(205) Then TurnEntity camera,0,-1,0

    RenderWorld

    Text 0,0,"[ / ] : segments   Arrow keys: move camera   Esc: exit"
    Text 0,20,"CreateSphere("+segments+")"

    Flip

Wend

End

Index