SpeedTree --> UE4 Lighting Issue

Tetranome

Hia! So I'm trying to wrap my head around SpeedTree in Unreal 4 and I'm having some lighting issues - which I'm guessing are somewhat related to normals? I've previously created trees in Maya successfully - but I'm getting some strange, ugly shadows in my new SpeedTree ones.

Here's an image with the bad lighting. In the foreground of the UE4 shots is my new tree, and in the background you can see my Maya trees that look much smoother overall. 



I've tried messing with the normal settings under "Lighting" in SpeedTree but all varieties of the settings seem to do little.

Thanks! 
...

chrisradsby

The tree in UE4 is casting shadows on itself, it doesn't matter if the Normals are pointing the same way the alpha planes will still cast a shadow. The tree in SpeedTree is also doing the same thing but the ambient light is much brighter in Speedtree. (White infact) 

- In Speedtree, click the lightsource at the top right of the viewport.
- Then to the left you have an ambient setting, pull that down to something much lower, and you're going to get a sense of how it'll look in your scene currently.

So you're options would be:
- Create plane-alphas that are not as dense as yours, casting less dense shadows.
- Manually control the ambient for the scene, making it brighter
- Make the leaves more translucent

Usually it's a mix of these that fixes some of the issues.

tmammela

In addition to previous suggestions, you can modify the default material created by SpeedTree import. Normally SpeedTree foliage will use opaque shading with normals adjusted to get smooth foliage-like shading. But you can enable "two sided foliage" shading mode and use that to control the look of the trees. It will increase the complexity of the material slightly, but not too much.

Also in SpeedTree you can adjust how the normals are generated and this will change how the shading looks like. Select the leaves and go to lighting tab.

Tetranome

Thank you very much gentlemen/ladies. I read somewhere that it was good to make dense leaf cards, but it appears I was mislead - or have followed the advice in the wrong direction. I will try these solutions!

tmammela

Tetranome said:

Thank you very much gentlemen/ladies. I read somewhere that it was good to make dense leaf cards, but it appears I was mislead - or have followed the advice in the wrong direction. I will try these solutions!

Dense leaf cards are good, for performance. Foliage is still difficult to do even for high end computers. Take a look at overdraw visualization mode in Unreal Engine. If you have lots of white and bright red, you are in trouble. And that is what you will get if not using dense leaf cards. Of course they are usually not good for the visual side of things, but that's what we have to deal with in real time rendering.

Tetranome

Ah, balance - like everything else in games then. Haha, awesome. I'll be trying to make some new cards

Steppenwolf

If it's purely an outdoor level you can disable Cast Shadows on your skylight. With indoor sections that will cause them to be too bright tho.

Tetranome

Is there a way to disable shadow casting from skylight on specific meshes? I see it doesn't have lighting channels
My rocks and such really get a lot from the skylight shadows, but the trees look far better without it. Hard decision!

roomi

Hey guys change Mip gen settings of your Atlas  to NoMipmaps & see the magic

Obscura

No mips can cause a lot of visual artifacts when the texture is viewed from far, or from grazing angles. Expect moire patterns and noise.