What does the Near Clip Plane effect do?

What does the Near Clip Plane effect do?

Article Details



Poster: peterm
Article ID: 1601
Posted: Tue 15 Nov 2016
Approved: Yes

QUESTION
What does the Near Clip Plane effect do?

ANSWER

Background:
In old versions of Lumion, overlapping surfaces would start to flicker when people moved the camera higher up (above the native Lumion terrain) due to limited accuracy in the so-called depth buffer of the graphics card.

The solution in scenes where the camera was high above the terrain was to apply a Near Clip Plane, and adjust the near clipping plane slider value until the flickering stopped.

However, many of our users didn't know that this effect existed, nor why they had to use this effect almost every time they were working on aerial views.

So, in Lumion 3.0, the developers decided to fix this flickering problem automatically, so that the near camera clip plane value now automatically increases as you move the camera further up, above the Lumion terrain.  As the near clip plane value increases, the depth buffer accuracy improves, and the flickering stops.

This works well in the majority of scenes, but not for scenes with skyscrapers for example, or scenes in which an imported terrain and buildings are high above the Lumion terrain.  The moment the camera gets close to a model which is high above the Lumion terrain, you'll notice that the near clip plane is clipping the model.


   


To prevent this from occurring in Build mode, you either have to move the model closer to the Lumion terrain - Refer our Knowledge Base Article:  My model is high above the terrain. How can I change its height?

Or, temporarily lock all models in your scene and then raise the Lumion terrain below the building, so that the vertical distance between the camera and the Lumion terrain is as small as possible. The reason is that the vertical distance between the camera and the Lumion Terrain basically adjusts the (automatic) near clip plane (and therefore also the depth buffer accuracy) on the fly to prevent surfaces that overlap or are close to each other from flickering.

If you can't move the building closer to the Lumion terrain (or the Lumion terrain closer to the building), you will have to learn to live with it in Build mode. However, you can still prevent it from occurring in Photo/Movie mode when rendering images/videos by adding the following to your clips/photos: New Effect -> Camera tab -> Near Clip Plane Effect.


Version 8   Version 7




Once you've done that, reduce the Near clip plane value and render your images/videos. Just bear in mind that doing so will make surfaces that overlap, or are close to each other flicker again, particularly far away from the camera.

TIP: Some users will also use a small Focal Length to widen the camera view, especially useful for room based views.  You can use the Near Clip Plane Effect to reduce the clipping of the walls close to the camera.  The value required will depend on the position of the model, camera view and Focal Length. In some cases there will be a range in which the correct clipping will work well.







SA Knowledge Base
© 2011 - 2018 SMFHacks.com