This blog describes my journey exploring storytelling - words, images and the sensations they generate. The lot, basically.

Saturday, September 21, 2013

MARI: Removing strong details in tiled base textures

When you put together a base texture, you want it to be a good neutral representation of the given surface, perhaps even with a bit of interesting details. 

But those details are a double edged sword, as they will also quickly show up as repeating patterns - giving away that this is not a custom painted texture, but a tiled texture.

What to do? 

You could just manually cover your object with the Paint Through tool, using only the more neutral parts of your base texture map. 

I like to keep things procedural as far as I can - it just gives way more flexibility for fast and painless editing and changes down the line. Also it can be a lot quickler to work this way. Let me show you a couple of nifty things you can do with MARI's 2.0 layers:

Enter our base texture, which has been tiled 15 times in both directions.

That gives us something looking like this:



A nice place to start for a copper object. However, it does have some pretty conspicuous black details. We need to remove a few of them to make sure the texture is not appearing so obviously repeating.

There are a couple of simple things we can do, before we have to dive into the nitty-gritty of carefully painting each one out.

Add another layer with our tiled copper texture, this time tiling it and rotating it differently (this one is set to 12 times repeats in both directions). This is to make sure that although it is the same texture, it will not sit exactly the same place on top of the other one.



Right click on the layer and add a Layer Mask for the layer. Set this one to Hide All. 

Having selected the Layer Mask (it should still be selected after you have added it, but if you have since clicked on other layers etc. it might have become unselected. If so click on it to select it, and it will glow orange, like in the photo) for your new tiled texture, select the Paint tool, pick a brush with soft edges, like Linear, and choose bright white as the colour to paint with.

So far we can not see the layer with the new tiled copper texture. But by painting on the layer mask, for that layer, with white, we will reveal the additional copper texture, where we want it to cover the black details in the layer below. The idea here is that, as we have changed the tiling and rotation of the same texture, we might use different parts of the texture to cover the areas of it, that we don't want.

In that way we can get rid of some of the black details, we don't want.


However, you are of course at the mercy of whether or not there will be a suitably neutral patch in the texture in the layer above to cover where there are disturbing details. This may, or may not be the case.

So what else can we do? 

Add another procedural layer on top, this time a Color Constant. Using the Color Picker, sample a representative neutral copper colour and set the colour of the Color layer to that.


Change blend mode to Lighten, and then the layer will only cover pixels darker than the neutral copper colour you have selected for it. It might bleed out too much the details of the copper base texture underneath so experiment with opacity till you have something that works.

Now we have taken those big black details in the texture down to a manageable level:

 


Let us just go through a variation here.




The above copper texture was a base and as such used the Normal blend mode. What if you use other blend modes which affect the layers below them? Then we need to change the approach slightly.




Here is a nice noisy texture that I am using as an Overlay to add details to my layers below it.


The problem is, if you have an Overlay layer and you are painting out details using another layer above it, also set to Overlay, you will get really dark patches where you mask in details from the layer above. Like this...




Fortunately MARI's new layer groups come to the rescue here. You add a group, place the two tiled textures inside the group - each set with Normal blend mode - and then let the Group have the work of carrying out the Overlay blend mode. Like so:




Result:


Pretty good, and definitely very quickly and easily. What about picking a neutral middle colour like we did before? Okay, but let's take it up a notch.

So we pick a neutral colour, and add that as a new procedural Color Constant layer. 

Set the blend mode of the layer to Lighten and experiment a bit with the opacity. This will cover everything darker than the colour we have picked for our procedural layer. This approach can be a bit heavy handed, and produce great areas now coloured with our chosen colour. You can lose a lot of interesting detail this way.

I have anxiously been waiting for the day when The Foundry will allow me to select colours, the same way I am able to do so in Photoshop.

This brings us to one of my absolute favourites of the many new features in MARI 2.0: Advanced Blend Modes!


No fear. This is not exactly selecting colours in a layer, like you would in Photoshop, but it allows me to affect particular colours just as if I had.


Notice the little green triangle next to your opacity slider (marked with a red rectangle below)? Go on click it. It will open the Aladdin's cave that Advanced Blend modes truly are.




First you need to change Blending from Basic to Advanced. Doing so gives you access to the Curves style controls for both your selected layer and the layer below it. In this case we only really want to affect the black spots in the layer below, so manipulating the curves for that layer (marked by the green rectangle) we pick what values of the layer below we want to affect with our Color Constant - in this case the darker values. 


The results are absolutely wonderful!


Smooth as a baby's... something. Oh MARI, how I love you. Let me count the ways!


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Friday, September 13, 2013

MARI: Distressed edges of bricks in bump map

You are working on a brick wall.

All the bricks are individually modelled. Lovely.

VFX Supervisor then decides that he wants all the edges of all the bricks all worn, torn and distressed in the bump map. Sells the illusion, it does. Takes a year to go over every single brick painting it in, it does.

Here is what you do:

Grab a few good rock textures from Texture Pilot or the like. Bring them into MARI's image manager and desaturate the texture images (Filters - Hue). Crank up the contrast a bit, adjusting the levels for example (Filters - Levels):



Add a new layer to your Bump map channel and set it to multiply blend mode.

Select MARI's Paint Through tool, using your greyscale rock texture and pick a brush, with reasonably soft edges, like Linear.



Now, using the Paint Through tool, you can quickly trace the edges of the bricks with the rock texture, which gives lovely organic and believable cracked edges on your bump map.

As quickly as you can trace the edges (use the structure of the wall to bundle your tasks together, so you work all the horizontal lines first and then vertical lines, for example) you'll go from this:



... to this:




Job done!


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