Thursday, April 27, 2023

Normal Map Tut for Affinity Photo

 Onegai shimasu (おねがい します)  🙇

I usually don't post any tutorials. However, I found that it was very tough to find a decent tutorial concerning the proper blend of normal maps for Affinity Photo. It took a couple of weeks to figure out the right way to do this in Affinity. So I decided to share what I learned. I can't make a vid due to my vocal disability. Hope this works for you. Please contact me with any questions.

Affinity Photo Norm Tut:

A simple overlay of the detail layer is ineffective as the result is a washed out blue channel and the z-depth info is flattened. This way is inaccurate.

For those of us in the industry that don’t use Photoshop/Substance and want to blend normal detail into a standard normal map, the following will be of good use. This uses layers in Affinity Photo and is very easy.

Start with 2 normal maps: a standard main normal and a detailed normal.

When you start, always remember to duplicate the base layer you're going to manipulate.

Remember the basic of how normals are determined in 2D space: x, y, z = r, g, b

  • You will need to use the Layer Pallet in order to control the layer type. You will also need to use the Channels Pallet to manipulate the rgb channels. You’ll need to create the Spare Channels here in order to properly manipulate the rgb channels. I like think of the Spare Channels as an extra clip loaded with the right greyscale/white image ammo to be used upon the correct rgb channel.

  • Open the normal map that needs normal detail. This will be it’s own untouched layer and the foundation.

  • Bring in the detail normal on a new layer. Set it below the foundation normal layer so its hidden so that its ready to be used and hidden.

  • Duplicate the Detail Normal image twice and group them above the main Normal layer. Rename this group layer to something appropriate. You’ll be able to change the opacity of this group layer of the details to your liking.

  • Now for some organization:
    • Rename the two duplicated detail layers so that they make sense to you.

    • I renamed mine to r/g_overlay (red/green channels overlay layer) and b_multiply (blue channel multiply layer).

  • Make a fill layer as the top layer (this will be temporary) with medium grey (128, 128, 128).

  • Make a fill layer as the top layer (this will be temporary) with white. This will be the top layer.

  • Select the topmost visible fill layer:
    • Select the red, green, or blue channel (they should all be the same level of grey/white).

    • Right click the r, g, or b channel and select Create Spare Channel. A new spare channel will appear.

    • Right click it,  rename the channel (to keep organized).

    • Delete the topmost fill layer that corresponds with the color you made the Spare Channel for.

  • Repeat the above steps for the next Fill Layer.

  • Select the first Detailed Layer dupe (r/g_overlay):

    • Select the white Spare Channel,

    • Right Click and select Load To r/g_overlay Blue

    • Set this layer to Overlay (this image should have the Blue Channel as white).

  • Select the next Detailed Layer dupe (b_multiply):
    • Select the grey Spare Channel,

    • Right Click and select Load To b_multiply Red

    • Right Click and select Load To b_multiply Green

    • Set this layer to Multiply (this image should have the Red/Green Channels as grey).

  • The final result is the normal image now has detail where the opacity of the detail can be controlled.

 The steps ablove seem lengthy, yet after doing this a couple of times it will get very fast.

Its always best to keep the original layered master file in case changes need to be made.