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How would I render Triangles linking nodes for my Triangle Terrain Generator?

Asked by

9 years ago

Hello, I'm working on a triangle terrain generator, and already have node generation (using math.noise), but don't have the faintest clue how to go about creating triangles between nodes to create the actual terrain.

What should I do? Are there any tutorials I should read, any advice you have?

1 answer

Answered by

adark 5487

9 years ago

stravant wrote the original triangle fill code that most if not all triangle fill plugins use in some fashion:

001local function setupPart(part)
002    part.Anchored = true
003    part.FormFactor = 'Custom'
004    part.CanCollide = PolyDraw.CanCollide
005    part.BrickColor = PolyDraw.BrickColor
006    part.TopSurface = 'Smooth'
007    part.BottomSurface = 'Smooth'
008end
009 
010function CreateTriangle(parent, a, b, c)
011    local this = {}
012    local mPart1 = Instance.new('WedgePart')
013    setupPart(mPart1)
014    local mPart2 = Instance.new('WedgePart')
015    setupPart(mPart2)
016    function this:Set(a, b, c)
017        --[[       edg1
018            A ------|------>B  --.
019            '\      |      /      \
020              \part1|part2/       |
021               \   cut   /       / Direction edges point in:
022           edg3 \       / edg2  /        (clockwise)
023                 \     /      |/
024                  \<- /        `
025                   \ /
026                    C
027        --]]
028        local ab, bc, ca = b-a, c-b, a-c
029        local abm, bcm, cam = ab.magnitude, bc.magnitude, ca.magnitude
030        local edg1 = math.abs(0.5 + ca:Dot(ab)/(abm*abm))
031        local edg2 = math.abs(0.5 + ab:Dot(bc)/(bcm*bcm))
032        local edg3 = math.abs(0.5 + bc:Dot(ca)/(cam*cam))
033        -- Idea: Find the edge onto which the vertex opposite that
034        -- edge has the projection closest to 1/2 of the way along that 
035        -- edge. That is the edge thatwe want to split on in order to 
036        -- avoid ending up with small "sliver" triangles with one very
037        -- small dimension relative to the other one.
038        if edg1 < edg2 then
039            if edg1 < edg3 then
040                -- min is edg1: less than both
041                -- nothing to change
042            else           
043                -- min is edg3: edg3 < edg1 < edg2
044                -- "rotate" verts twice counterclockwise
045                a, b, c = c, a, b
046                ab, bc, ca = ca, ab, bc
047                abm = cam
048            end
049        else
050            if edg2 < edg3 then
051                -- min is edg2: less than both
052                -- "rotate" verts once counterclockwise
053                a, b, c = b, c, a
054                ab, bc, ca = bc, ca, ab
055                abm = bcm
056            else
057                -- min is edg3: edg3 < edg2 < edg1
058                -- "rotate" verts twice counterclockwise
059                a, b, c = c, a, b
060                ab, bc, ca = ca, ab, bc
061                abm = cam
062            end
063        end
064 
065        --calculate lengths
066        local len1 = -ca:Dot(ab)/abm
067        local len2 = abm - len1
068        local width = (ca + ab.unit*len1).magnitude
069 
070        --calculate "base" CFrame to pasition parts by
071        local maincf = CFrameFromTopBack(a, ab:Cross(bc).unit, -ab.unit)
072 
073        --make parts
074        if len1 > 0.2 then
075            mPart1.Parent = parent
076            mPart1.Size = Vector3.new(0.2, width, len1)
077            mPart1.CFrame = maincf*CFrame.Angles(math.pi,0,math.pi/2)*CFrame.new(0,width/2,len1/2)
078        else
079            mPart1.Parent = nil
080        end
081        --
082        if len2 > 0.2 then
083            mPart2.Parent = parent
084            mPart2.Size = Vector3.new(0.2, width, len2)
085            mPart2.CFrame = maincf*CFrame.Angles(math.pi,math.pi,-math.pi/2)*CFrame.new(0,width/2,-len1 - len2/2)
086        else
087            mPart2.Parent = nil
088        end
089    end
090    function this:SetProperty(prop, value)
091        mPart1[prop] = value
092        mPart2[prop] = value
093    end
094    this:Set(a, b, c)
095    function this:Destroy()
096        mPart1:Destroy()
097        mPart2:Destroy()
098    end
099    return this
100end
 View all 100 lines...

If you want to recreate the features that a specific plugin has, look into its code to see how its modified stravant's fill.

...which you can do by going to C:\Users\user\AppData\Local\Roblox\InstalledPlugins, look at all of them (the folder names are random), and open the rbxm. unmiss 337 — 9y

How would I render Triangles linking nodes for my Triangle Terrain Generator?

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