itch.io

The same to you! Thanks. BTW I can't get the ray intersect triangle function to work (works sometimes), any Idea? I'm using the rit() function by elias_t, a mod of the original by sswift who converted it from a Tomas Moller Here's the original, but I'd rather find an other one than to fix this, I tried for hours. So, just if you have a working, reliable RIT() function somewhere.

;-------------------------------------------------------------------------
;A function that finds out if a line segment and a triangle intersect
;and calculates the intersection point in the array picked(2)
;where picked(0)=pickedx,..1=y,..2=z

;

;This actually the function posted by sswift and originally made by Tomas Moller.

;Only here we get also the intersection point !

;

;mod by elias_t

;

;-------------------------------------------------------------------------

;stores the picked location

;Dim picked#(2)

Function rit(Px#,Py#,Pz#, Dx#,Dy#,Dz#, V0x#,V0y#,V0z#, V1x#,V1y#,V1z#, V2x#,V2y#,V2z#, Extend_To_Infinity=1, Cull_Backfaces=0)

;-

E1x# = V2x# - V0x#

E1y# = V2y# - V0y#

E1z# = V2z# - V0z#

;-

E2x# = V1x# - V0x#

E2y# = V1y# - V0y#

E2z# = V1z# - V0z#

; Hxyz = Crossproduct(Dxyz, E2xyz)

Hx# = (Dy# * E2z#) - (E2y# * Dz#)

Hy# = (Dz# * E2x#) - (E2z# * Dx#)

Hz# = (Dx# * E2y#) - (E2x# * Dy#)

; Calculate the dot product of the above vector and the vector between point 0 and point 2.

A# = (E1x# * Hx#) + (E1y# * Hy#) + (E1z# * Hz#)

;cull

If (Cull_Backfaces = 1) And (A# >= 0) Then Return 0

;parralel

If (A# > -0.00001) And (A# < 0.00001) Then Return 0

;Inverse Determinant

F# = 1.0 / A#

;-

Sx# = Px# - V0x#

Sy# = Py# - V0y#

Sz# = Pz# - V0z#

; U# = F# * (DotProduct(Sxyz, Hxyz))

U# = F# * ((Sx# * Hx#) + (Sy# * Hy#) + (Sz# * Hz#))

;check u

If (U# < 0.0) Or (U# > 1.0) Return 0

; Qxyz = CrossProduct(Sxyz, E1xyz)

Qx# = (Sy# * E1z#) - (E1y# * Sz#)

Qy# = (Sz# * E1x#) - (E1z# * Sx#)

Qz# = (Sx# * E1y#) - (E1x# * Sy#)

; V# = F# * DotProduct(Dxyz, Qxyz)

V# = F# * ((Dx# * Qx#) + (Dy# * Qy#) + (Dz# * Qz#))

;check v

If (V# < 0.0) Or ((U# + V#) > 1.0) Return 0

T# = F#*((E2x#*Qx#)+(E2y#*Qy#)+(E2z#*Qz#)) 

; If T#<0 Return 0; orig

If T#<=0 Return 0

If Extend_To_Infinity=0 And T#>1 Return 0

pickU=U

pickV=V

;-------------------------------------------------

;Calculate intersection point

nx#=(E1y*E2z)-(E1z*E2y)

ny#=(E1z*E2x)-(E1x*E2z)

nz#=(E1x*E2y)-(E1y*E2x)

d# = -  nx*V0x - ny*V0y - nz*V0z 

denom# = nx*Dx + ny*Dy + nz*Dz

mu# = - (d + nx*Px + ny*Py + nz*Pz) / denom

picked(0) = Px + mu * DX

picked(1) = Py + mu * Dy

picked(2) = Pz + mu * Dz

;-------------------------------------------------

;intersects

Return 1

End Function