[UE3/UDK] Mixing Normal Maps

Approaches on mixing/blending normal maps using UE3' material editor.


Base Normal Map

Detail Normal Map

#1 UDN / 52 instructions (47+5)

#2 Whiteout / 53 instructions (47+6)

#3 Unity / 55 instructions (47+8)

#4 RNM / 55 instructions (47+8)

 

[UDK Quick Tip] Alpha Channel sRGB

Just a quick reminder that alpha channels of a textures won't be stored in sRGB color space. Having linear data is crucial for height or normal maps, however when using the alpha channel for something like a specular map it will just look wrong.

A quick way to fix this is to do a linear -> sRGB conversion inside the material, by taking the power of 2.2. The downside of this method is an extra 5 instructions. Instead it's good practice to multiply the alpha channel by itself (=taking the power of 2) which is slightly wrong but only adding a single instruction.

[Blender/UDK] Fire Hydrant Model

Lately I've been practicing some Sub-D modeling. The Polycount thread on that topic was a great resource for recreating various shapes to begin with. Afterwards I started to make whole models; this fire hydrant was the first one. The topology/edgeflow is a bit messy where the main cylinder gets extruded and causes some pinching. But it was sufficient to bake a proper normal map for the low poly. The model is also slightly out of proportions since it's too elongated, espacially at the top.


High Poly / Wireframe in Blender

Textured low poly in Blender (GLSL viewport grab)

Textured low poly + LoD model in UDK

Blendswap Download: http://www.blendswap.com/blends/view/70874
Sketchfab Preview: https://sketchfab.com/show/96ded07b6ac1434b9225531540fe2bda

[WIP] Parallax Corrected Cubmaps in UDK/UE3

A first approach on using parallax corrected Cubemaps in UDK/UE3, more to follow.


Cubemap with default reflection vector

 
Parallax corrected Cubemap

  

Reference

Material Setup