[name objname] intersect object1 object2 end [transformations] [textures]
The intersect object includes those parts common to both objects.
I often find that the applications of intersect are less obvious than union and difference. I think that we are trained from primary school in adding and subtracting, and so using an intersection operator is much less intuitive.
This example shows a simple use for intersect: a series of boxes are
intersected with a sphere. The sphere is used to "cut" the edges of the
boxes (and the resulting shape also uses the sphere's surface definition
on the edges.
Figure 5-7
/*
intersect.ray
intersect a series of boxes with a sphere
Stephen Peter 2 aug 92
*/
eyep 1250 450 1600
lookp 0 0 0
screen 300 200
light 1 point 1500 1000 1000
surface white
ambient .3 .3 .3
diffuse .4 .4 .4
specular .4 .4 .4
reflect .2
specpow 50
surface blue
ambient 0 0 .3
diffuse .2 .2 .4
specular .4 .4 .4
reflect .2
specpow 25
name boxes
list
box -600 -455 -600 600 -445 600
box -600 -305 -600 600 -295 600
box -600 -155 -600 600 -145 600
box -600 -5 -600 600 5 600
box -600 155 -600 600 145 600
box -600 305 -600 600 295 600
box -600 455 -600 600 445 600
end
name frame
intersect
object white boxes
sphere blue 500 0 0 0
end
object frame rotate 0 0 1 60
object frame rotate 0 0 1 -60
object frame
Go to next section: Difference Object.
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THE END - Notes on Rayshade - 5 - Objects - Intersection