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Removing Light From A Texture In Photoshop

 

Remove light from your texture is the step by step walkthrough for Tip 3: Clean your maps in my  “Texturing Digital Vegetation”-article.

Fixing an overlit texture by brute force
As you probably know, it pays to treat every texture-extraction as a potential hero-texture, as even background textures may end up near your camera. And most of you know that a texture with blowouts, or plain overlit areas will probably make your render look off, especially if the light seemingly comes from another direction than the light defined in your scene.
Usually, it pays to rescan the texture, or to find a better alternative (Like complaining to the person who sold it to you – if you did not scan or shoot it yourself).
However, if that’s not an option, here’s a basic, brute-force technique you can use to clean up an issue like this. I’ll use a leaf from the birch in the main illustration as a basic example.
Remember to save as you go, and to experiment – what may look OK on the texture in this walk-through, may need some tweaks on a different one.
Sometimes you have to work with what you’re given – we’ll turn the not-so-workable leaf on the left into a renderable filler-type leaf on the right

Sometimes you have to work with what you’re given – we’ll turn the not-so-workable leaf on the left into a renderable filler-type leaf on the right

Brute force cleanup

If you have to work with a texture that is very damaged, or overlit, your best bet may be to do a total texture reboot – this means getting rid of the initial colour, whilst keeping (most) of the image’s details.  The simplest way to do this, is to use a High Pass filter, and use it as a base for recolouring your texture. Mostly used as an alternative to the Unsharp Mask, or Smart Sharpen filters by photographers, the High Pass filter is also a genius way to clean up and recolour bad textures, as it retains noise and leaves any area which is not an edge untouched.  At a low (1-5) setting, it also gives you a superflat greyscale texture  which will facilitate a good basis for bump- and normalmapping.  We want to get rid of the overly lit areas in the leaf on the right, and make them more even – like the leaf on the right. Use the techniques outlined below to fine-tune your own images – even brute force hacks can benefit from a little finesse.

  • Step 1:  I’ve created a small 756×756 file for you to practise on – Birchleaf1.TIF. Grab and open it from the Downloads tab on top of the page.
  • Step 2Create a new layer on top of Original Leaf, SHIFT+CTRL/CMD+N and call it Background.
  • Step 3: Fill it with green, i.e RGB 69, 94,29
  • Step 4Duplicate the Original_Leaf layer on top of Background and  call it HighPass.
  • Step 5Duplicate HighPass on top of itself, and name it ReColour
  • Step 6Turn the layer off by clicking the eye next to it
  • Step 7Select the HighPass Layer – this layer will control the initial flattening of the image
  • Step 8Go to Filters>Other>HighPass, and set it to 4 or 5. As you can see, this completely evens the leaf out in greyscale
  • Step 9Because of the low-resolution scan, there’s a lot of noise in the texture. Go to Filter>Reduce Noise. As this will be a background, and not a hero-texture, we shouldn’t worry too much about losing detail. Therefore, set strength to 10 and the other sliders to 0. Remove JPG-artfeacts doesn’t do much on this particular leaf, so it’s  up to you whether you want to check it or not. I didn’t.
  • Step 10Select the ReColour layer, turn it on, and set it to Soft Light in the Layer Palette
  • Step 11As you can see, we now have a very flat, but greenish leaf, with some detail, and greyish green instead of the overlit areas.
  • Step 12CTRL/CMD + Click the ReColour Layer’s thumbnail to select the alpha
  • Step 13SHIFT+CTRL/CMD+N to create a new layer, and name it ReColour_Equaliser
  • Step 14:Fill it with i.e RGB 69, 94,29 and set it to overlay. You now have a very basic, but flat texture. For variation, try setting the ReColour layer to Color Dodge, or varying the greens
A few simple steps will give you a basic, flat texture

A few simple steps will give you a basic, flat texture – remember to desaturate a little

Making your colours pop

You could say we’re all done at this stage – the texture is flat, and ready to be used as a filler, or overpaint-base – with some detail from the stem left in. However, if you’d like to take it a step further, and pop a little more vibrance  and detail into the leaf, use adjustment layers – they will give you a lot of non-invasive freedom in tailoring a texture to your exact needs :

  • Step 1: Add a layer between ReColour_Equaliser and Channel Mixer, name it ReColour_Darken
  • Step 2Fill it with RGB 23, 39,13
  • Step 3Set it to Color Dodge, (you can also use Screen or Linear Dodge for a more springlike green – but you’ll need to tone its vibrance down a bit)
  • Step 4Go to Layer>New Adjustment Layer>Levels. We’re using Levels to “buffer” the harshness of the next Adjustment Layer we’re setting up
  • Step 5Set the numbers in the layer dialog to 0, 1.18, 255 – we’re using grey to drive the “buffer”
  • Step 6For once, we’ll leave the layer on normal.
  • Step 7:  Go to Layer>New Adjustment Layer>Channel Mixer
  • Step 8In the Channel Mixer, set the channels to RGB 120,118, 22 (Which is OK for now, we’re not going to put this in a closeup on TV, so the colours don’t need to make up an even 100. We’re boosting the red to make the veins stand out, and “mature” the green – Birchleaves in late summer are quite dark. The result will look very reddish/yellowish, and not in a good way.
  • Step 9Set it to Overlay. Presto – leaf with decent veins!

If you’d like to turn down the vibrance of the colours, try using a Brightness/Contrast asjustment layer, and reducing the opacity of the ReColour_Darken layer to 50%. I set the adjustment layer to -26 Brightness and -29 Contrast, with use legacy checked. To tone down the yellow – use colour theory, and use a purple- or blue-tinged overlay, either via Fill- or Adjustment Layer

We've made the colours pop - remember that we're not after a good picture, we're after what looks good to decent in a render

Using the basic cleaned up texture on the left, we made it  pop in the texture on the right – remember you’re not after a good picture, you’re after what  can be made to look decent in a render

Cleanup and finalisation

Now we’re done, time to clean up our file:

  • Step 1Create a folder in the Layer Palette, and call it Originals
  • Step 2Select Original_Leaf, Highpass, ReColour, ReColour_Equaliser, ReColour_Darken and Channel Mixer, and move them into Originals
  • Step 3Duplicate them by rightclicking
  • Step 4Move the copies out of the folder
  • Step 5Press CTRl/CMD + E to flatten the duplicated layers, and call it BirchLeaf_Final. This ensures that you can always go back and change things
  • Step 6Make sure only the Birchleaf_Final and the Background layer are visible by turning off the visibility of the Originals Folder. Click the eye next to it
  • Step 7CTRL/CMD + Click  BirchLeaf’s thumbnail in the Layer palette – you should see a selection appear
  • Step 8Click the Channels tab
  • Step 9Press “create new channel from Selection”at the bottom of the palette  – this will automatically create an Alpha.
  • Step 10Rename it to Alpha from Alpha 1. Make sure its not on or active when you return to the layers palette (Make sure the RGB layer is visible and active in channels, if you’re not sure)
  • Step 11Return to Layers. Before you deselect, press SHIFT+CTRL/CMD+I to invert your selection. Press Delete, in order to make sure the layer is clean outside the leaf.
  • Step 12Deselect (CTRL/CMD+D) – all done.
Download Tutorial Files

Download Conditions and terms of use

By downloading the files you agree not to:

  • sell,
  • re-distribute
  • or republish
  • -any of the files on this page.

Using the  textures for your own (commercial) rendered images is perfectly fine, and I don’t need you to credit me.

Files are copyright Cirstyn Bech-Yagher, represented by Lyngtveit &co, Attorneys at law. Feel free to contact me regarding any usage questions you may have :)

Downloadable Files

Here is a sample Vue texture setup as used in the renders shown – I only have Vue 2014 installed, so I couldn’t test with older Vue versions

 

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