hi there...

i have learned some new techniques for 3d max in school, which have made my life a lot easier, including using booleans to cut, unite and intersect...

the thing is... i have found that sometimes, the boolean tool doesn't work as expected... when subtracting a shape from a complex mesh, i found that on accasion, it will make the cut, but not fill in the hole....

for example, to cut out the headlights on the hood of my flying car, i superimposed a box over the car body part and used a boolean to subtract the box from the mesh.... this should have created a box shaped dent into the hood, but all it did was cut out the outline of the box, leaving an open hole where the headlights should be

i managed to fix this once by selecting all vertices and welding them with a low threshold to eliminate any loose ends or colocated vertices, but this doesn't seem to work every time

anyone else had this problem? i figure there must be an easy fix or something i might be overlooking... anyways, i thought i'd ask

cheers...

Moach

That is a general problem of booleans when used on meshes. (Nurbs Booleans are way better but unusable
for realtime models). Actually you only should use
booleans if there is really no other way cause there are a
lot of problems
booleans can cause !!

The problem you described is the most obvious. Like Milton allready explained this is connected to
the size/complexity difference between the two objects.
This problem is caused by an internal treshold
value that cannot be set by the user.
You have a small chance to get rid of it.. by slightly moving one of the operands. (Activate in the "Display/Update" rollout
"results + hidden ops".. than switch to Subobject Level "Operands" and you can select and move the Objects).
But that´s not the only problem ! Even if the boolean function works as expected.. always carfully examine the rims where the boolean operation cut the mesh. It sometimes happens that you have small open gaps..
unwelded vertex.. and so on. And the last problem is
that boolean functions produce an uneven mesh with a
lot of "spiked polys" (long tapered poly´s). This can get
you into trouble if it comes to smoothing depending on the
shape of the object. (No problem on even surfaces... but
a big problem on uneven/bend surfaces)

If you are working with 3dsmax... there was recently
a plugin released (from Discreet for subscribtion user)
called "Pro Booleans Extension". This adds a new boolean object.. wich claims to be better than the old function...

But first make shure there´s no other way to model your object !! Booleans should always stay the last choice !!

cheers,

sam