Blending Normals

Trying to world align blend normals, I knew I had this working at one point but I have since broke it.

Fairly simple setup, want the rock normal where the rock texture is, etc. On top of that I have a distance normal blend which works great. Blend bias and blend normal are setup exactly like the diffuse, same values.

I’ve tried a bazillion different configurations (the explicit normal output too, although there is no documentation on it so maybe I used it wrong) on this now plus it looks like the Detail Lighting mode is broken in the editor as well.

So where am I going wrong?


You’re interpolating one normal map to the other. Instead of blending, corrected for angles, you just wind up softening everything. The distance blend doesn’t make much sense to me, it just softens things further. I love the results of RNM blending. UE4 has a similar node called “BlendAngleCorrectedNormals” that does the same thing, and it also corrects for 8-bit normal maps. You should definitely use that to blend your normals.

Based on the mask the WorldAlignedBlend node creates, which is based on the angle of the terrain.

I’m not sure what is going on, I recreated the shader in another scene exactly and it works as expected. Really confused now.


It doesn’t do that-it fades a larger normal designed for the whole landscape, it creates large details in the distance that fade to the tile normals when you move closer.

If I could use a mask to determine the blending areas I would use that- I’m not sure that is possible with that node.

I believe the culprit was the in world vector parameter- posting in case anyone else wants to reproduce this. Deleted that and it works great!

Personally I detest distance-based fades because the end result is going to be expensive to render and lower quality than if you just blended all three of the normal maps together. The only situation you should do that is if you really want your distances to be softer than up close. I don’t think you’re saving any memory doing otherwise, and even if you are, the memory savings are not worth the cost of a full-scale interpolation. Landscape and sky are your two biggest screen hogs: if your landscape is too expensive, then your game will suffer tremendously.