Culling near and far clipping

[d.kupavcev]

Do I understand correctly that the objects are not culling  by the near and far clipping planes.
In methods
int WorldBoundFrustum :: inside_planes_fast (const Vec3 & point, Scalar radius) const
{
if (dot (planes [0], point) <-radius) return 0;
if (dot (planes [1], point) <-radius) return 0;
if (dot (planes [2], point) <-radius) return 0;
if (dot (planes [3], point) <-radius) return 0;
return 1;
}

int WorldBoundFrustum :: inside_planes_fast (const Vec3 & min, const Vec3 & max) const
{
if (inside_plane (planes [0], min, max) == 0) return 0;
if (inside_plane (planes [1], min, max) == 0) return 0;
if (inside_plane (planes [2], min, max) == 0) return 0;
if (inside_plane (planes [3], min, max) == 0) return 0;
return 1;
}

There are no checks boundSphere boundBox on the near and far planes:

   if (dot (planes [4], point) <-radius) return 0;
   if (dot (planes [5], point) <-radius) return 0;

and

   if (inside_plane (planes [4], min, max) == 0) return 0;
   if (inside_plane (planes [5], min, max) == 0) return 0;

What is the reason?

P.S.  Unigine doesn't have technologies for solving issues concerning depth buffer presicion. (eg to draw cosmic space).
For example: "3D Engine Design for Virtual Globes" - Patrick Cozzi, Kevin Ring - paper "Rendering with Multiple Frustums".


 

[ulf.schroeter]

d.kupavcev, on 30 Jun 2015 - 08:52 AM, said:

 

P.S. Unigine doesn't have technologies for solving issues concerning depth buffer presicion. (eg to draw cosmic space).

For example: "3D Engine Design for Virtual Globes" - Patrick Cozzi, Kevin Ring - paper "Rendering with Multiple Frustums".

 

Depth buffer precision has been a long time discussion issue :) (though cosmic space range capability is only seldomly required...)

 

https://developer.unigine.com/forum/topic/138-solved-near-clipping-plane-and-z-fighting/?p=671

[binstream]

Since we are now working on space-related project, that issue will be resolved for sure.

[d.kupavcev]

Great! But there are no checks for boundSphere and boundBox in relation to  near and far planes. What is the reason?

[unclebob]

Hi there!

 

There's another version of such method which checks all 6 planes called BoundFrustum::inside_planes. For performance purposes we also wrote faster version that skips far and near clipping planes so don't worry.

[d.kupavcev]

Thank you!