Landscape Lighting Issue

Hi all. Hoping someone can give me some pointers on this as I’ve only found one solution and I’m not sure its ideal.

Basically. I have a small 1km exterior scene which im working on. It has a variable day and night with the sun moving n what not. But whenever the sun is under the terrain the light obviously shines through it.

I’ve dealt with this in the past in UDK by switching the sun light off at night (gradually), or by adding a BSP under the level to block the light.

But using BSP’s isnt practical, and changing the suns brightness never really has the desired effect.

So far, the best solution I have come up with, is to make the landscape material Two-Sided.
This works perfectly. But what I need to know is if there are any downsides to this. Performance issues and the like.

Any ideas?

Thanks in advance people. Much appreciated!

The downside is that you’re rendering your material twice. Depending on the number of texture samples and complexity of your material this can potentially cause performance issues.

Setting the light level to a lower value or 0 is the best solution here.

I’ve got a sample project using Gregdumb’s Time of Day tutorial that I’ve extended for a smoother transition between day and night along with using a skylight actor. You can check that out here:

I hope this helps.