Real-time Mesh Deformation Functions

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Diggsey

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Joined: 24th Apr 2006

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Posted: 11th Apr 2007 13:48 Edited at: 13th Apr 2007 11:43

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Here are some functions which will deform a mesh in real-time. You can use them to blow stuff up, and simulate car crashes, etc.

Unfortunately, it does not yet support limbs, due to the missing command: Make mesh from limb

Also, it requires the matrix_utils plugin, or you have to write your own find free mesh() function

edit:
DEMO PROGRAM! (includes 1 extra function)

sync on

make object sphere 1,100,50,50
set object cull 1,0
ID as dword
ID = SetupDeformableObject(1,1)
autocam off
make object sphere 2,5
color object 1,rgb(255,0,0)
color object 2,0

do

start = timer()

text 0,0,"Use arrowkeys to move bomb on the x/z plane."
    text 0,20,"Use ctrl/shift to move bomb vertically."
    text 0,40,"Press space detonate bomb."

move object 2,upkey()-downkey()
    move object right 2,rightkey()-leftkey()
    move object up 2,shiftkey()-controlkey()

if spacekey() and detonate = 0
        make object sphere 3,5
        make object sphere 4,7
        disable object zdepth 4
        position object 3,object position x(2),object position y(2),object position z(2)
        position object 4,object position x(2),object position y(2),object position z(2)
        color object 3,rgb(255,0,0)
        color object 4,rgb(255,255,0)
        detonate = 1
    endif

if inkey$() = "p"
        paused = not paused
        while inkey$() <> ""
            sync
        endwhile
    endif

if detonate > 0 and paused = 0
        position camera 0,0,0
        turn camera left 0.5
        move camera -200
        scale object 3,200+detonate,200+detonate,200+detonate
        scale object 4,detonate,detonate,detonate
        ghost object on 3
        ghost object on 4
        inc detonate,20
        SphereDestroyFaces(ID, object position x(3),object position y(3),object position z(3),0,0,0,object size x(3,1)/2)
        ApplySpherePushDeformation(ID, object position x(4),object position y(4),object position z(4),object size x(4,1)/2)
        if detonate > 1000
            detonate = 0
            delete object 3
            delete object 4
        endif
    endif
    
    repeat
    until start+20<timer()

sync

loop

function SetupDeformableObject(ObjNum as dword, MemNum as dword)

ID as dword

MeshNum = find free mesh()
    make mesh from object MeshNum,ObjNum
    make memblock from mesh MemNum,MeshNum
    delete mesh MeshNum
    ID = make memory(8)
    *ID = ObjNum
    inc ID,4
    *ID = MemNum
    dec ID,4

endfunction ID

function SphereDestroyFaces(ID as dword, X as float, Y as float, Z as float, Xpos as float, Ypos as float, Zpos as float, Radius as float)

ObjNum as dword
    MemNum as dword
    Dist as float
    Xp as float
    Yp as float
    Zp as float
    Xo as float
    Yo as float
    Zo as float

Dist = Radius*Radius
    MeshNum = find free mesh()
    ObjNum = *ID
    inc ID,4
    MemNum = *ID
    StepN = memblock dword(MemNum,4)
    VertN = ((memblock dword(MemNum,8)-1)*StepN)+12
    n = -1
    for i = 12 to VertN step StepN
        inc n
        if n > 2 then n = 0
        Xp = memblock float(MemNum,i)
        Yp = memblock float(MemNum,i+4)
        Zp = memblock float(MemNum,i+8)
        Xo = X-Xp
        Yo = Y-Yp
        Zo = Z-Zp
        if ((Xo*Xo)+(Yo*Yo)+(Zo*Zo)<=Dist)
            Xp = Xpos
            Yp = Ypos
            Zp = Zpos
            select n
                case 0
                    off1 = 0
                    off2 = StepN
                    off3 = StepN+StepN
                endcase
                case 1
                    off1 = 0-StepN
                    off2 = 0
                    off3 = StepN
                endcase
                case 2
                    off1 = 0-(StepN+StepN)
                    off2 = 0-StepN
                    off3 = 0
                endcase
            endselect
            write memblock float MemNum,i+off1,Xp
            write memblock float MemNum,i+off1+4,Yp
            write memblock float MemNum,i+off1+8,Zp
            write memblock float MemNum,i+off2,Xp
            write memblock float MemNum,i+off2+4,Yp
            write memblock float MemNum,i+off2+8,Zp
            write memblock float MemNum,i+off3,Xp
            write memblock float MemNum,i+off3+4,Yp
            write memblock float MemNum,i+off3+8,Zp
        endif
    next i

make mesh from memblock MeshNum,MemNum
    change mesh ObjNum,0,MeshNum
    delete mesh MeshNum

endfunction

function ApplySpherePushDeformation(ID as dword, X as float, Y as float, Z as float, Radius as float)

ObjNum as dword
    MemNum as dword
    Dist as float
    Xp as float
    Yp as float
    Zp as float
    Xo as float
    Yo as float
    Zo as float

local dim CalcVerts(18000) as dword
    local dim FaceIndex(18000) as byte
    VCC as integer
    VCC = -1

Dist = Radius*Radius
    MeshNum = find free mesh()
    ObjNum = *ID
    inc ID,4
    MemNum = *ID
    StepN = memblock dword(MemNum,4)
    VertN = ((memblock dword(MemNum,8)-1)*StepN)+12
    n = -1
    for i = 12 to VertN step StepN
        inc n
        if n > 2 then n = 0
        Xp = memblock float(MemNum,i)
        Yp = memblock float(MemNum,i+4)
        Zp = memblock float(MemNum,i+8)
        Xo = Xp-X
        Yo = Yp-Y
        Zo = Zp-Z
        if ((Xo*Xo)+(Yo*Yo)+(Zo*Zo)<=Dist)
            d# = Radius/sqrt((Xo*Xo)+(Yo*Yo)+(Zo*Zo))
            Xmo = Xo*d#
            Ymo = Yo*d#
            Zmo = Zo*d#
            Xp = X+Xmo
            Yp = Y+Ymo
            Zp = Z+Zmo
            write memblock float MemNum,i,Xp
            write memblock float MemNum,i+4,Yp
            write memblock float MemNum,i+8,Zp

inc VCC
            CalcVerts(VCC) = i
            FaceIndex(VCC) = n
        endif
    next i

REM Now calculate post deformation vertices
    REM (Only ones of altered faces)
    for a = 0 to VCC
        i = CalcVerts(a)
        n = FaceIndex(a)

rem GET TRIANGLE'S VERTICES
        select n
            case 0
                off1 = 0
                off2 = StepN
                off3 = StepN+StepN
            endcase
            case 1
                off1 = 0-StepN
                off2 = 0
                off3 = StepN
            endcase
            case 2
                off1 = 0-(StepN+StepN)
                off2 = 0-StepN
                off3 = 0
            endcase
        endselect

VX1# = memblock float(MemNum,i+off1)
        VY1# = memblock float(MemNum,i+off1+4)
        VZ1# = memblock float(MemNum,i+off1+8)
        VX2# = memblock float(MemNum,i+off2)
        VY2# = memblock float(MemNum,i+off2+4)
        VZ2# = memblock float(MemNum,i+off2+8)
        VX3# = memblock float(MemNum,i+off3)
        VY3# = memblock float(MemNum,i+off3+4)
        VZ3# = memblock float(MemNum,i+off3+8)

AX# = VX1#-VX3#
        AY# = VY1#-VY3#
        AZ# = VZ1#-VZ3#

BX# = VX2#-VX1#
        BY# = VY2#-VY1#
        BZ# = VZ2#-VZ1#

NX# = (AY# * BZ#) - (AZ# * BY#)
    	NY# = (AZ# * BX#) - (AX# * BZ#)
    	NZ# = (AX# * BY#) - (AY# * ax)

NT# = sqrt(NX#*NX#+NY#*NY#+NZ#*NZ#)
        NX# = NX#/NT#
        NY# = NY#/NT#
        NZ# = NZ#/NT#

write memblock float MemNum,i+off1+12,NX#
        write memblock float MemNum,i+off1+16,NY#
        write memblock float MemNum,i+off1+20,NZ#

write memblock float MemNum,i+off2+12,NX#
        write memblock float MemNum,i+off2+16,NY#
        write memblock float MemNum,i+off2+20,NZ#

write memblock float MemNum,i+off3+12,NX#
        write memblock float MemNum,i+off3+16,NY#
        write memblock float MemNum,i+off3+20,NZ#
    next a

make mesh from memblock MeshNum,MemNum
    change mesh ObjNum,0,MeshNum
    delete mesh MeshNum

endfunction

+ Code Snippet

sync on

make object sphere 1,100,50,50
set object cull 1,0
ID as dword
ID = SetupDeformableObject(1,1)
autocam off
make object sphere 2,5
color object 1,rgb(255,0,0)
color object 2,0

do

    start = timer()

    text 0,0,"Use arrowkeys to move bomb on the x/z plane."
    text 0,20,"Use ctrl/shift to move bomb vertically."
    text 0,40,"Press space detonate bomb."

    move object 2,upkey()-downkey()
    move object right 2,rightkey()-leftkey()
    move object up 2,shiftkey()-controlkey()

    if spacekey() and detonate = 0
        make object sphere 3,5
        make object sphere 4,7
        disable object zdepth 4
        position object 3,object position x(2),object position y(2),object position z(2)
        position object 4,object position x(2),object position y(2),object position z(2)
        color object 3,rgb(255,0,0)
        color object 4,rgb(255,255,0)
        detonate = 1
    endif

    if inkey$() = "p"
        paused = not paused
        while inkey$() <> ""
            sync
        endwhile
    endif

    if detonate > 0 and paused = 0
        position camera 0,0,0
        turn camera left 0.5
        move camera -200
        scale object 3,200+detonate,200+detonate,200+detonate
        scale object 4,detonate,detonate,detonate
        ghost object on 3
        ghost object on 4
        inc detonate,20
        SphereDestroyFaces(ID, object position x(3),object position y(3),object position z(3),0,0,0,object size x(3,1)/2)
        ApplySpherePushDeformation(ID, object position x(4),object position y(4),object position z(4),object size x(4,1)/2)
        if detonate > 1000
            detonate = 0
            delete object 3
            delete object 4
        endif
    endif
    
    repeat
    until start+20<timer()

    sync

loop

function SetupDeformableObject(ObjNum as dword, MemNum as dword)

    ID as dword

    MeshNum = find free mesh()
    make mesh from object MeshNum,ObjNum
    make memblock from mesh MemNum,MeshNum
    delete mesh MeshNum
    ID = make memory(8)
    *ID = ObjNum
    inc ID,4
    *ID = MemNum
    dec ID,4

endfunction ID

function SphereDestroyFaces(ID as dword, X as float, Y as float, Z as float, Xpos as float, Ypos as float, Zpos as float, Radius as float)

    ObjNum as dword
    MemNum as dword
    Dist as float
    Xp as float
    Yp as float
    Zp as float
    Xo as float
    Yo as float
    Zo as float

    Dist = Radius*Radius
    MeshNum = find free mesh()
    ObjNum = *ID
    inc ID,4
    MemNum = *ID
    StepN = memblock dword(MemNum,4)
    VertN = ((memblock dword(MemNum,8)-1)*StepN)+12
    n = -1
    for i = 12 to VertN step StepN
        inc n
        if n > 2 then n = 0
        Xp = memblock float(MemNum,i)
        Yp = memblock float(MemNum,i+4)
        Zp = memblock float(MemNum,i+8)
        Xo = X-Xp
        Yo = Y-Yp
        Zo = Z-Zp
        if ((Xo*Xo)+(Yo*Yo)+(Zo*Zo)<=Dist)
            Xp = Xpos
            Yp = Ypos
            Zp = Zpos
            select n
                case 0
                    off1 = 0
                    off2 = StepN
                    off3 = StepN+StepN
                endcase
                case 1
                    off1 = 0-StepN
                    off2 = 0
                    off3 = StepN
                endcase
                case 2
                    off1 = 0-(StepN+StepN)
                    off2 = 0-StepN
                    off3 = 0
                endcase
            endselect
            write memblock float MemNum,i+off1,Xp
            write memblock float MemNum,i+off1+4,Yp
            write memblock float MemNum,i+off1+8,Zp
            write memblock float MemNum,i+off2,Xp
            write memblock float MemNum,i+off2+4,Yp
            write memblock float MemNum,i+off2+8,Zp
            write memblock float MemNum,i+off3,Xp
            write memblock float MemNum,i+off3+4,Yp
            write memblock float MemNum,i+off3+8,Zp
        endif
    next i

    make mesh from memblock MeshNum,MemNum
    change mesh ObjNum,0,MeshNum
    delete mesh MeshNum

endfunction

function ApplySpherePushDeformation(ID as dword, X as float, Y as float, Z as float, Radius as float)

    ObjNum as dword
    MemNum as dword
    Dist as float
    Xp as float
    Yp as float
    Zp as float
    Xo as float
    Yo as float
    Zo as float

    local dim CalcVerts(18000) as dword
    local dim FaceIndex(18000) as byte
    VCC as integer
    VCC = -1

    Dist = Radius*Radius
    MeshNum = find free mesh()
    ObjNum = *ID
    inc ID,4
    MemNum = *ID
    StepN = memblock dword(MemNum,4)
    VertN = ((memblock dword(MemNum,8)-1)*StepN)+12
    n = -1
    for i = 12 to VertN step StepN
        inc n
        if n > 2 then n = 0
        Xp = memblock float(MemNum,i)
        Yp = memblock float(MemNum,i+4)
        Zp = memblock float(MemNum,i+8)
        Xo = Xp-X
        Yo = Yp-Y
        Zo = Zp-Z
        if ((Xo*Xo)+(Yo*Yo)+(Zo*Zo)<=Dist)
            d# = Radius/sqrt((Xo*Xo)+(Yo*Yo)+(Zo*Zo))
            Xmo = Xo*d#
            Ymo = Yo*d#
            Zmo = Zo*d#
            Xp = X+Xmo
            Yp = Y+Ymo
            Zp = Z+Zmo
            write memblock float MemNum,i,Xp
            write memblock float MemNum,i+4,Yp
            write memblock float MemNum,i+8,Zp

            inc VCC
            CalcVerts(VCC) = i
            FaceIndex(VCC) = n
        endif
    next i

    REM Now calculate post deformation vertices
    REM (Only ones of altered faces)
    for a = 0 to VCC
        i = CalcVerts(a)
        n = FaceIndex(a)

        rem GET TRIANGLE'S VERTICES
        select n
            case 0
                off1 = 0
                off2 = StepN
                off3 = StepN+StepN
            endcase
            case 1
                off1 = 0-StepN
                off2 = 0
                off3 = StepN
            endcase
            case 2
                off1 = 0-(StepN+StepN)
                off2 = 0-StepN
                off3 = 0
            endcase
        endselect

        VX1# = memblock float(MemNum,i+off1)
        VY1# = memblock float(MemNum,i+off1+4)
        VZ1# = memblock float(MemNum,i+off1+8)
        VX2# = memblock float(MemNum,i+off2)
        VY2# = memblock float(MemNum,i+off2+4)
        VZ2# = memblock float(MemNum,i+off2+8)
        VX3# = memblock float(MemNum,i+off3)
        VY3# = memblock float(MemNum,i+off3+4)
        VZ3# = memblock float(MemNum,i+off3+8)

        AX# = VX1#-VX3#
        AY# = VY1#-VY3#
        AZ# = VZ1#-VZ3#

        BX# = VX2#-VX1#
        BY# = VY2#-VY1#
        BZ# = VZ2#-VZ1#

    	NX# = (AY# * BZ#) - (AZ# * BY#)
    	NY# = (AZ# * BX#) - (AX# * BZ#)
    	NZ# = (AX# * BY#) - (AY# * ax)

        NT# = sqrt(NX#*NX#+NY#*NY#+NZ#*NZ#)
        NX# = NX#/NT#
        NY# = NY#/NT#
        NZ# = NZ#/NT#

        write memblock float MemNum,i+off1+12,NX#
        write memblock float MemNum,i+off1+16,NY#
        write memblock float MemNum,i+off1+20,NZ#

        write memblock float MemNum,i+off2+12,NX#
        write memblock float MemNum,i+off2+16,NY#
        write memblock float MemNum,i+off2+20,NZ#

        write memblock float MemNum,i+off3+12,NX#
        write memblock float MemNum,i+off3+16,NY#
        write memblock float MemNum,i+off3+20,NZ#
    next a

    make mesh from memblock MeshNum,MemNum
    change mesh ObjNum,0,MeshNum
    delete mesh MeshNum

endfunction

Here are the current functions:

ID as dword = SetupDeformableObject(ObjNum as dword, MemNum as dword)

ObjNum as dword = RemoveDeformableObject(ID as dword)

ApplySphereStickyDeformation(ID as dword, X as float, Y as float, Z as float, Xmo as float, Ymo as float, Zmo as float, Radius as float)

ApplySpherePushDeformation(ID as dword, X as float, Y as float, Z as float, Radius as float)

PositionVertexA(ID as dword, X as float, Y as float, Z as float, Xpos as float, Ypos as float, Zpos as float, Near as float)

PositionVertexB(ID as dword, Vertex as dword, Xpos as float, Ypos as float, Zpos as float)

OffsetVertexB(ID as dword, Vertex as dword, Xmo as float, Ymo as float, Zmo as float)

Number as dword = GetObjectNumber(ID as dword)

Number as dword = GetObjectMemblock(ID as dword)

FindObjectLocalCoords(ID as dword, X as float, Y as float, Z as float)

Result as float = GetObjectLocalCoordX(ID as dword)
Result as float = GetObjectLocalCoordY(ID as dword)
Result as float = GetObjectLocalCoordZ(ID as dword)

Here is a definition of each parameter:
ID as dword : Unique ID of deformable object, must be stored in a dword variable.
ObjNum as dword : Object Number.
MemNum as dword : Memblock Number to store mesh data.
X,Y,Z as float : Position where deforming happens.
Xmo/Ymo/Zmo as float : Direction of deformation.
Radius : Radius of deformation sphere.

Here is a definition of each function:
SetupDeformableObject : Must be called on an object prior to first deformation. Returns the ID needed to reference the object.
RemoveDeformableObject : Frees all memory created with SetupDeformableObject
ApplySphereStickyDeformation : Pushes all vertices within sphere in the direction of deformation
ApplySpherePushDeformation : Pushes all vertices out of the sphere in their current angle from the center of the sphere.
PositionVertexA : Positions all vertices within a sphere at a point
PositionVertexB : Positions a single verticex at a point
OffsetVertexB : Offsets a single verticex
GetObjectNumber : Gets object number from ID
GetObjectMemblock : Gets memblock number from ID
FindObjectLocalCoords : Transforms world coords into local coords (requires ezrotate)
GetObjectLocalCoordX : Retrieves X value from FindObjectLocalCoords (requires ezrotate)
GetObjectLocalCoordY : Retrieves Y value from FindObjectLocalCoords (requires ezrotate)
GetObjectLocalCoordZ : Retrieves Z value from FindObjectLocalCoords (requires ezrotate)

Functions working on:
ApplySimplePlaneDeformation : Push all vertices in front of a plane.
ApplyComplexPlaneDeformation : Push all vertices in a custom direction if a plane goes through them.
ApplySimpleCircleDeformation : Push all vertices in front of a circle.
ApplyComplexCircleDeformation : Push all vertices in a custom direction if a circle goes through them.

For me to complete those four functions, I need someone to answer my question in THIS thread.

And finally, here is the code: UPDATED WITH NINE NEW FUNCTIONS!

function SetupDeformableObject(ObjNum as dword, MemNum as dword)

ID as dword

MeshNum = find free mesh()
    make mesh from object MeshNum,ObjNum
    make memblock from mesh MemNum,MeshNum
    delete mesh MeshNum
    ID = make memory(8)
    *ID = ObjNum
    inc ID,4
    *ID = MemNum
    dec ID,4

endfunction ID

function RemoveDeformableObject(ID as dword)

ObjNum as dword
    MemNum as dword
    ObjNum = *ID
    inc ID,4
    MemNum = *ID
    delete memory ID-4
    delete memblock MemNum

endfunction ObjNum

function ApplySphereStickyDeformation(ID as dword, X as float, Y as float, Z as float, Xmo as float, Ymo as float, Zmo as float, Radius as float)

ObjNum as dword
    MemNum as dword
    Dist as float
    Xp as float
    Yp as float
    Zp as float
    Xo as float
    Yo as float
    Zo as float

local dim CalcVerts(18000) as dword
    local dim FaceIndex(18000) as byte
    VCC as integer
    VCC = -1

Xmo = Xmo * 1.02
    Ymo = Ymo * 1.02
    Zmo = Zmo * 1.02

Dist = Radius*Radius
    MeshNum = find free mesh()
    ObjNum = *ID
    inc ID,4
    MemNum = *ID
    StepN = memblock dword(MemNum,4)
    VertN = ((memblock dword(MemNum,8)-1)*StepN)+12
    n = -1
    for i = 12 to VertN step StepN
        inc n
        if n > 2 then n = 0
        Xp = memblock float(MemNum,i)
        Yp = memblock float(MemNum,i+4)
        Zp = memblock float(MemNum,i+8)
        Xo = X-Xp
        Yo = Y-Yp
        Zo = Z-Zp
        if ((Xo*Xo)+(Yo*Yo)+(Zo*Zo)<=Dist)
            inc Xp,Xmo
            inc Yp,Ymo
            inc Zp,Zmo
            write memblock float MemNum,i,Xp
            write memblock float MemNum,i+4,Yp
            write memblock float MemNum,i+8,Zp