When will the scenario of one triangle intersecting with another triangle really happen? I thought each point in the triangle was in one plane and that it would share its edges with other triangles in other planes to form the surface of the object, thereby the different triangles intersecting like that would never happen?

cupoftea

I am curious to know what happens when a pixel is half covered by triangle 1 and half by triangle 2. Do you just take each triangle's colors and mix them according to how much of the pixel they are covering? Wouldn't that produce odd colors in the middle of screen or does it not matter since it is just 1 pixel?

mdsavage

@BellaJ: while that might generally be true for a single mesh, what if you have multiple intersecting meshes? Then it's certainly feasible that a pair of triangles, one from each mesh, could intersect in this way.

keenan

@Bellaj The real time graphics pipeline just takes an arbitrary collection of triangles as input, so there's no reason they can't intersect each other.

keenan

@cupoftea You tell me: suppose we use the supersampling strategy discussed later in these slides (say, using 4 samples per pixel). How will the color behave in the situation you describe, i.e., when the pixel is partially covered by two triangles of different colors?

When will the scenario of one triangle intersecting with another triangle really happen? I thought each point in the triangle was in one plane and that it would share its edges with other triangles in other planes to form the surface of the object, thereby the different triangles intersecting like that would never happen?

I am curious to know what happens when a pixel is half covered by triangle 1 and half by triangle 2. Do you just take each triangle's colors and mix them according to how much of the pixel they are covering? Wouldn't that produce odd colors in the middle of screen or does it not matter since it is just 1 pixel?

@BellaJ: while that might generally be true for a single mesh, what if you have multiple intersecting meshes? Then it's certainly feasible that a pair of triangles, one from each mesh, could intersect in this way.

@Bellaj The real time graphics pipeline just takes an arbitrary collection of triangles as input, so there's no reason they can't intersect each other.

@cupoftea You tell me: suppose we use the supersampling strategy discussed later in these slides (say, using 4 samples per pixel). How will the color behave in the situation you describe, i.e., when the pixel is partially covered by two triangles of different colors?