One surface

Blitz3D Forums/Blitz3D Programming/One surface

Jeroen

(Posted 2004) [#1]

Hi!

Is it possible to convert a multiple surface mesh to a single sutface mesh? (I don't care how it looks texture wise, as long as the shape is the same)

big10p

(Posted 2004) [#2]

Yes, as long as the mesh doesn't contain too many verts/tris to fit in a single surface. Just build the new mesh from scratch by iterating through all the verts/tris and copying them into the new mesh.

Rottbott

(Posted 2004) [#3]

You could even save the texturing by combining the textures and adjusting the UVs accordingly, but you could potentially end up with some very large textures.

Jeroen

(Posted 2004) [#4]

thanks guys. I'm not very good at manually building a mesh, I'm gonna take a shot at it!

Jeroen

(Posted 2004) [#5]

based on some code by Sswift, I am trying to achieve this, but all meshes change in some sort of abstract cubism :(

Type triangle
	Field index
	Field surface
End Type



Function newMeshOneSurface(ThisMesh)

		; Create a new mesh.
		NewMesh = CreateMesh()	
		Surfaces=CountSurfaces(ThisMesh)
		destSurface = CreateSurface(NewMesh)

		; Loop through each surface of the mesh.
		For Surface_Index = 1 To Surfaces

			; Get the pointer to the this surface and the number of vertices in it.
			SrcSurface = GetSurface(ThisMesh, Surface_Index)
			Tris = CountTriangles(SrcSurface)
	
			; Copy all the vertices from the source surface to the destination surface.
			SrcVerts = CountVertices(SrcSurface)
			For VertLoop = 0 To SrcVerts-1
		
				Vx#  = VertexX#(SrcSurface, VertLoop)
				Vy#  = VertexY#(SrcSurface, VertLoop)
				Vz#  = VertexZ#(SrcSurface, VertLoop)
				Vu#  = VertexU#(SrcSurface, VertLoop)
				Vv#  = VertexV#(SrcSurface, VertLoop)		
				Vw#  = VertexW#(SrcSurface, VertLoop)
				Vnx# = VertexNX#(SrcSurface, VertLoop)
				Vny# = VertexNY#(SrcSurface, VertLoop)
				Vnz# = VertexNZ#(SrcSurface, VertLoop)						
				Vr   = VertexRed(SrcSurface, VertLoop)
				Vg   = VertexGreen(SrcSurface, VertLoop)
				Vb   = VertexBlue(SrcSurface, VertLoop)
				AddVertex(DestSurface, Vx#, Vy#, Vz#, Vu#, Vv#, Vw#)
				VertexNormal(DestSurface, VertLoop, Vnx#, Vny#, Vnz#)
				VertexColor(DestSurface, VertLoop, Vr, Vg, Vb) 
	
			Next

			; Copy all triangles from the source surface to the destination surface.	
			SrcTris  = CountTriangles(SrcSurface)
			For TriLoop = 0 To SrcTris-1
	
				Copy_Tri = True
				
				For ThisTri.Triangle = Each Triangle
									
					; If this triangle is a coincident triangle that should be removed...
					If (ThisTri\Surface = SrcSurface) And (ThisTri\Index = TriLoop) 
						
						; Do not copy the triangle.
						Copy_Tri = False
						
						; Exit ThisTri loop early.
						Exit
						
					EndIf
						
				Next
	
	
				; If it's okay to copy this triangle...
				If Copy_Tri			
		
					V0 = TriangleVertex(SrcSurface, TriLoop, 0)
					V1 = TriangleVertex(SrcSurface, TriLoop, 1)
					V2 = TriangleVertex(SrcSurface, TriLoop, 2)
					AddTriangle(DestSurface, V0, V1, V2)
		
				EndIf
	
			Next
		
		Next
		Return NewMesh 
	End Function

Ross C

(Posted 2004) [#6]

Does the addmesh commands not combine and create one surface? I'm sure it does, but you lose the texture info i think for all but one surface.

Stevie G

(Posted 2004) [#7]

Yeah, addmesh will work as long as the surfaces share the same brush properties.

Rottbott

(Posted 2004) [#8]

I would do it like this (untested):

Function CollapseMesh(Mesh)

	BaseSurface = GetSurface(Mesh, 1)
	For i = 2 To CountSurfaces(Mesh)
		S = GetSurface(Mesh, i)
		For j = 0 To CountTriangles(S) - 1

			V0 = TriangleVertex(S, j, 0)
			V1 = TriangleVertex(S, j, 1)
			V2 = TriangleVertex(S, j, 2)

			NV0 = AddVertex(BaseSurface, VertexX#(S, V0), VertexY#(S, V0), VertexZ#(S, V0), VertexU#(S, V0), VertexV#(S, V0))
			VertexNormal BaseSurface, NV0, VertexNX#(S, V0), VertexNY#(S, V0), VertexNZ#(S, V0)
			VertexColor BaseSurface, NV0, VertexRed#(S, V0), VertexGreen#(S, V0), VertexBlue#(S, V0), VertexAlpha#(S, V0)

			NV1 = AddVertex(BaseSurface, VertexX#(S, V1), VertexY#(S, V1), VertexZ#(S, V1), VertexU#(S, V1), VertexV#(S, V1))
			VertexNormal BaseSurface, NV1, VertexNX#(S, V1), VertexNY#(S, V1), VertexNZ#(S, V1)
			VertexColor BaseSurface, NV1, VertexRed#(S, V1), VertexGreen#(S, V1), VertexBlue#(S, V1), VertexAlpha#(S, V1)

			NV2 = AddVertex(BaseSurface, VertexX#(S, V2), VertexY#(S, V2), VertexZ#(S, V2), VertexU#(S, V2), VertexV#(S, V2))
			VertexNormal BaseSurface, NV2, VertexNX#(S, V2), VertexNY#(S, V2), VertexNZ#(S, V2)
			VertexColor BaseSurface, NV2, VertexRed#(S, V2), VertexGreen#(S, V2), VertexBlue#(S, V2), VertexAlpha#(S, V2)

			AddTriangle BaseSurface, NV0, NV1, NV2
		Next
	Next

End Function

Jeroen

(Posted 2004) [#9]

w00t. Nice guys. Rottbott, looks good, but the mesh has still 23 surfaces. However, one texture is smeared all over the mesh.