UpdateNormals

UpdateNormals

Command Index · Blitz3D · Surfaces

UpdateNormals:Void mesh:Int32

Parameter	Mode	Type	Default	Description
mesh	In	Int32	required	Mesh handle.

Description

Works out the normals of every vertex of a mesh from its triangles. A normal tells lights which way a surface faces, so without it a mesh built from code is lit wrongly or not at all. Call it after adding vertices and triangles and again after you moved vertices. Shared vertices get the average of the triangles around them, which makes round shapes look smooth.

Examples

Graphics3D 320, 240, 0, 2
SetBuffer BackBuffer()
camera = CreateCamera()
PositionEntity camera, 0, 7, -9
RotateEntity camera, 38, 0, 0
light = CreateLight()
RotateEntity light, 40, 60, 0
; A bumpy field, built from a grid of 12 by 12 vertices.
mesh = CreateMesh()
surf = CreateSurface(mesh)
For z = 0 To 11
	For x = 0 To 11
		AddVertex surf, x - 5.5, Sin(x * 40) * Cos(z * 40) * 0.6, z - 5.5
	Next
Next
For z = 0 To 10
	For x = 0 To 10
		i = z * 12 + x
		AddTriangle surf, i, i + 12, i + 1
		AddTriangle surf, i + 1, i + 12, i + 13
	Next
Next
UpdateNormals mesh
EntityColor mesh, 120, 200, 120
RenderWorld
Flip
WaitKey

Media

Related Commands

PaintSurface, TriangleVertex, VertexAlpha, VertexBlue

Command Index · Blitz3D · Surfaces