No intersection detected for coplanar triangles

[minitoine]

Specific case where coplanar triangles do not trigger an intersection

T1:
(-1.000,0.000,0.000),(2.000,0.000,-2.000),(2.000,0.000,2.000)
T2:
(0.551,0.000,-0.796),(1.224,0.000,0.326),(3.469,0.000,1.000)

fig 9 test  IV.b

On a [p1,p2,r1] >0 et il y a une intersection.

Si [p1,p2,r1] <0 alors la droite p1p2 va séparer les 2 triangles 
puisque l’orientation  de T1 nous permet de dire que q1 est du meme coté que r1
Si [p1,p2,r1]=0 alors on a p2 entre p1 et r1 et l’intersection est p2

Si [p1,p2,r1]>0 alors il me semble qu’un cas a été oublié,
il faut encore tester le triangle q1 r2 r1
si [q1,r2,r1] >0 alors q1r1 sépare les deux triangles
si [q1, r2, r1] <= 0 alors [q1 r1] coupe [p2 r2] et il y a intersection

• Add failing test
• Check paper's authors email response about an error in the paper (in french)

[minitoine]

https://www.geogebra.org/calculator/wbu7xcrj

[georgpukk]

Found a coplanar case where intersection is not detected:

import { Triangle, Vector3 } from 'three'
import { trianglesIntersect, Intersection } from 'fast-triangle-triangle-intersection'

const t1 = new Triangle(
	new Vector3(0, 0, 0),
	new Vector3(0, 0, 8),
	new Vector3(8, 0, 0)
)

const t2 = new Triangle(
	new Vector3(2, 0, 2),
	new Vector3(1, 0, 4),
	new Vector3(9, 0, 0)
)

const intersection = trianglesIntersect(t1, t2)

console.log('Intersection.Coplanar', intersection === Intersection.Coplanar)

[minitoine]

Please don't comment on a closed issue. I will open one for you (#4).
For now, if you invert t1 and t2, intersection is detected. I'll will have a look at this.