Normal Map and Linear Workflow

Normal Mapping

Normal mapping is a bump mapping technique for changing the appearance of the shading for an object. It does so by perturbing the shading normals. Each channel of the normal map corresponds to a dimension in 3d space X, Y, and Z.

The normal map iam using is a tangent space normal map.

render-normal-map1

Linear Workflow

I had some headaches getting the dome light and normalmap to work because I didnt account for this linear workflow.

Linear workflow is a rendering workflow that deals with colour space management throughout the rendering process. It ensures the correctness of shading and lighting.

Theres alot of information on this subject I will jsut post a few links:

http://renderman.pixar.com/view/LinearWorkflow

Understanding Linear Workflow – Working In Floating Point

http://filmicgames.com/archives/299

What this means for me:

  1. Everything should be calculated in linear space.
  2. Images loaded in need to be loaded with an inverse gamma curve (1/2.2) applied to it to linearize it.
  3. HDRI and Normal map images do not need to be gamma corrected and should always be left at 1.0.
  4. Once the image has been rendered we apply agamma curve of 2.2 back when saving it out as a sRGB encoded image.

 

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