Friday, November 22, 2013

[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.

Sunday, November 3, 2013

[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:
Sketchfab Preview: