MARI: Distressed painted metal texture from scratch - Part 3

"Start with what is known, and what is hidden will be revealed."  - Rembrandt van Rijn

 

We'll take Rembrandt's wisdom and the approach of building up our textures layer by layer in order create the last of the secondary maps (bump) we need for the jerry can. For the first part of this tutorial, which looks at the diffuse colour maps for our jerry can, please go to http://marquepierre.blogspot.co.uk/2013/10/mari-distressed-painted-metal-from.html and for the second part, which covers the spec maps, please see http://marquepierre.blogspot.co.uk/2013/12/mari-distressed-painted-metal-texture.html.

Imperfection is key to successfully achieving the ilusion of realism and avoiding that computer generated look, and as such wear and tear is an important consideration for a texture artist. Which brings us to the bump maps. When people use the word "texture" outside of CGI, the meaning they refer to is pretty much what we use a bump map to illustrate: The texture of a surface, in terms of bumpiness, roughness and other smaller topographic details in the surface. The bump map adds lovely details, which are mostly only visible when the object is fairly close to the camera. It helps us to break up specular highlights and many other things. In a bump map 50% grey means that the surface is smooth and has neither indentations nor protrusions. White means details that protrudes out from the surface and black of course means details are recesses upon the surface.


Anyway, let's put together the bump map for the jerry can, using what we already have of information in the diffuse map.

To this end duplicate the Diffuse channel and use the duplicate for our bump map. In the Channel palette, right click on the Diffuse channel. Select Copy from the menu. Right click in the empty space on the Channel palette and select Paste from the menu. Now we have a duplicate of the Diffuse channel. Double-click on the new channel named "Diffuse Copy" and rename it to something suitable, like Bump or BMP.

First things first. When I paint secondary maps I set my Mari viewport to 50 percent grey. This allows me to visually gauge how far I am from my 50 percent grey midpoint. Beats bringing out the Color Picker all the time (although that certainly is useful to double-check values with). So right click on any empty and unused part of your Mari viewport. Select Display Properties.

 Under Display Properties, under Background we have two colour swatches, which combined can create a gradient in the background of your viewport. Click each of them (Top and Bottom) and select a 50% grey, and hit Ok.

If you work in flat lighting mode (F1) then you will always be able to quickly compare the values of your bump map against the even grey background of the viewport. 

Building our layers, we want to work from a 50% grey bottom layer - which in a bump map would represent a perfectly even surface. That wil be our starting point, upon which we will add dents, scratches and all the other goodness a bump map allows us to portray. So start by adding a Procedural Layer - Basic - Color and set it to 50% grey. 

So a 50% grey object set on a similarly coloured background, and your viewport should look like the right side (the flat lighting) of this image:

Let's start adding in our details from the creation of our colour map.

The first thing we want to use is the paint on the metal. That paint would sit slightly higher than the underlying metal itself. More specifically, as the green paint layer was a procedural basic color layer masked out in places, we need to use the mask. So right click on the mask symbol and then Layer Mask - Make Mask Stack. This turns our mask into a proper layer, which we can copy and add other layers to in a regular layer stack style.

Also it changes the icon from the mask icon to the mask stack icon:

Now, if you click on the new mask stack icon, a new layer window will open. Select the layer there in and copy it  (right clicking on it, will give you a copy, paste etc. menu). Paste it into our bump channel above the 50% grey procedural colour layer. Create a layer group for it and drag our mask layer into the group. Now change the blend mode for the layer group to Multiply and the opacity to something like that 0.3. This is what my bump map looks like so far:

In summary, what we have done here is creating a difference in height between the paint on the can and the aluminum underneath. Notice that the rubber spout is darker all over. This comes from our original mask, which of course masked away the paint from the rubber spout. In any case, we can leave it for now, as bumps very much work off differences in values. Globally on the spout we right now have a darker value, but the values of the details we will add on top of this darker value will still have the correct differences anyway. Kinda like adding 2 to 0 or 2 to 2, both will give a value which has increased with 2. That is how I see it. Does that make sense?

Moving on...

Move your aluminum base layer to sit on top of what we have so far. Change the blend mode to Overlay and the opacity to something like 0.25. What that does it gently add a bit of variation to our jerry can. Obviously a used jerry can is not completely smooth even on the big swathes of painted metal. We need to break those surfaces up ever so slightly, and preferably in an organic way. Our aluminum base will do this nicely.

Just as we want to break up the even spaces on the metal, so we also need to add a bit of similar detail to our rubber spout. Let's see what we can reuse of existing layers on the spout.

Your rubber base and rubber detail layers could be useful here. I took the rubber base layer and changed the blendmode to Multiply and lowered the opacity all the way down to 0.043. The rubber details layer I used with the blendmode of Color Dodge and an opacity of 0.07. So only adding these details in very, very lightly, but enough to break up the rubber spout, so it will not look like smooth porcelain etc. Here is what I got so far:

Remember our general dirt layer? We used a nice concrete texture to help paint it. As an object becomes dirty, that dirt will also add to the shape or roughness of the object. Drive your shiny new car through a muddy field, and what was previously smooth painted metal will now have bumpy mud on it. On a much smaller scale, we will use that dirt layer to add the bumps corresponding to the information in the colour map. Of this needs to be on a very small scale. Turn on that dirt layer and change the blend mode to Hard Light (as we want both the light and the dark information). I dialed my opacity all the way down to 0.043. You can barely see these details with the naked eye (unless you got a swanky 4K monitor), but with bump maps, little scratches can quickly end up looking like massive gouges in the render, so subtlety is imperative. Here is my bump map at this point:

Speaking of bump maps and scratches, let's move on to this more meaty subject. For the scratches on the can, I want to both use the general scratches we painted and also use a higher contrast version of those. With the higher contrast scratches I want to create a smaller number of more pronounced scratches. So we need to copy our scratches layer and place it in a new layer group. Add on top of the scratches layer in there an adjustment layer - contrast. Adjust your contrast to fit. Here are my scratches post contrast adjustment on their own:

Then change the blend mode of the layer group to Soft Light and the opacity to something like 0.2. Put together with the other layers, this is what it should look like:

That is a nice subtle start to our scratches. Let's turn it up a notch. So if we go back to our original scratch layer, here we will get the majority of the information, which will drive our scratches' bumps. To make sure the bigger details of the texture come out, I changed the blend mode to Hard Mix and took the opacity down to 0.3. In close up, it looks like this:

 

 All told, this is my jerry can so far:

Let's bring in the rust details. Make a layer group for your rust layer, and add an adjustment layer - HSV on top, crank the saturation down to 0. Or you could also add an adjustment layer - Luminosity, which does the same job, or if you are an enemy of non-destructive editing, you could run a filter on your rust layer (Hue or Luminosity for example). You get the point... So with our rust detail all converted to greyscale, change the blend mode of the rust layer group to Color Burn and the opacity to something like 0.236. Now our rust details will have a suitably bumpy surface.

 

Actually. I am still not happy with the way the rust is portrayed bump-wise. I want something more grainy. Rust has that crystalized kind of surface. I am thinking, generate some noise and overlay with the rust bumps we already have to get that grainy feel. Create a layer group and add a procedural layer - Noise - Cellular. Depending on your overall rust look, the noise needs to be quite small. 

Add a layer mask to the rust noise detail layer group and set it to hide all. What I did next was to take a rust texture and using the paint through tool and an organic brush, I painted into the mask where I wanted this noise detail on top of my rust. Here is what I painted onto my layer mask:

Change the blend mode of the layer group to Multiply and take the opacity down to something like 0.227. Up close you can see (compare with the rust bump close up above) the added detail provided by the noise layer:

That takes my bump map to its final stage:

Which rendered out, contributed to this look:

In my final instalment of this mini-series, I will go over setting up our shaders and lighting. Then I am looking forward to seeing your renders of this simple Mari texturing project.




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MARI: Distressed painted metal texture from scratch - Part 2

"Start with what is known, and what is hidden will be revealed."  - Rembrandt van Rijn

 

We'll take Rembrandt's wisdom and the approach of building up our textures layer by layer in order create the secondary maps (bump and specular) we need for the jerry can. For the first part of this tutorial, which looks at the diffuse colour maps for our jerry can, please go to http://marquepierre.blogspot.co.uk/2013/10/mari-distressed-painted-metal-from.html

The spec map is often considered the most-valuable-player of all the texture maps. When objects are so far away from the camera, that the diffuse map cannot be made out anymore, you can usually still see the effects of the spec map. The opposite end of that spectrum would probably be bump maps, which are the first to go as the camera pulls away from a model. The spec map will simply put control how shiny our object appears; how much of the light that hits the object is reflected back. Black equals the light-eating power of a black hole, where white equals the mirror shine of chrome.

Anyway, let's start putting together the spec map for the jerry can, using what we already have of information in the diffuse map.

To this end we will duplicate the Diffuse channel and use the duplicate for our spec map. In the Channel palette, right click on the Diffuse channel. Select Copy from the menu. Right click in the empty space on the Channel palette and select Paste from the menu. Now we have a duplicate of the Diffuse channel. Double-click on the new channel named "Diffuse Copy" and rename it to something suitable, like Spec.

In the Layers palette for the new Spec channel, add an HSV adjustment layer as the top-most layer of the stack. Take saturation slider all the way down to 0, and now our duplicated diffuse channel is all greyscale as a spec map needs to be.Turn off the visibility (click on the little eyeball icon next to each layer) of all the layers in the channel, and then we will bring them in as need be.

Add a procedural layer (Basic - Color), set the colour to black (don't use complete black, or white in your textures, it messes up the shader math); put 0.114 in each of the RGB channels.

This "black" will be a base for the rubber spout of the jerry can. So why don't you add an empty layer group and drag the procedural color layer into the group. Add a layer mask to the group by selecting the group, right clicking on it and selecting layer mask - add mask. Whether you go for Reveal All or Hide All, paint with pure white or black in your layer mask, so only the spout is affected by the procedural color layer. For good measure, I have added a white color layer underneath to help our spout to stand out.

Other than the procedural layer with the black colour, which we have just inserted at the bottom, your lowest layer should be your aluminum base layer. We need that. Click on the eyeball left of the layer in the layers palette to toggle its visibility on. The aluminum texture will both give a nice neutral base to build upon as well as lot of organic details and variation, which suits a metal can. So far, so good.

Next I want to add a touch of ambient occlusion. In corners dirt and dust will gather automatically due to inaccesability, which makes it more unlikely to get wiped off by regular use. Most kinds of ordinary dust and dirt will lower the shininess of a surface, so using ambient occlusion to make these areas darker works well (darker is less reflective or shiny in our spec map, mind you). A tiny touch will do.

Click on the Add Procedural Layer button in the layers palette. Select Geometry - Ambient Occlusion. Set the blend mode of the layer to Multiply and the opacity to 0.150. If you don't have something like this...

... it might be because you haven't calculated your ambient occlusion yet. In that case, select your jerry can as an object. Go to the Objects menu and select Ambient Occlusion. Mari will calculate for a while, and then you will have your lovely ambient occlusion.

Remember your Dirt layer? Turn that back on (click on the eyeball to the left of the layer name). This is what I have:

Next we want to bring the scratches back into play. If memory serves, the scratches layer from the diffuse map was set to Hard Light blend mode and 0.798 opacity. That should do nicely for the purpose of the spec map as well, so turn the layer's visibility back on.

 
The spills we added from down the front from the spout and to the base of the can also need to be in the spec map. However, they were set to Vivid Light blend mode before and 0.552 opacity. Change the blend mode of the Spills layer to Overlay and crank the opacity up to 1.0. Which should look something like this.

Lovely.

Onto our Dust_broad group. Therein we painted a broad and generic dust layer, masked by Ambient Occlusion. Turn the visibility of the Dust_broad layer group on. We should be able to use the blend mode (Overlay) and opacity as is. So far, so good:

We also have the Dust_detail layer group, where we added more specific dust around the base of the spout etc. Turn on the visibility of the Dust_detail layer group and make sure the blend mode is set to Overlay and full opacity.

I am looking at our spec map and I would like the scratches to be more pronounced. As light moves across the jerry can, the scratches would be a very distinctive feature. Aluminum has a dull glow, as the surface is oxidized over time, also you have the paint, which obscures metal, but where the scratches are, the aluminum will be naked and in some places freshly scratched - revealing the full extent of its shininess in places. Copy the Scratches layer (Right click on the Scratches layer and select Copy and then right click again and select Paste). We still want all the light and dark information of those scratches cranked up to full effect, so blend mode should still be Hard Light. I further took the opacity up to a full 1.0. 

So that is the scratches. How about rust? How does rust affect specularity? In my experience, rust dramatically dulls the reflectivity of metal. What is least shiny thing you know? From where I am sitting, the carpet underneath my feet has next to no reflection. Rust is pretty close to that. Do a quick google search for rust and you will see that there are a lot of different types of rust, which again would mean a lot of different looks of rust. Of course it not completely diffuse, but close, and so we aim for darkness where we have our rusty patches.

Our rust layer was set to multiply. Turn on the visibility and crank up the darkness it leaves by changing blend mode to Color Burn. It should look something like this...

Zooming close in on the rust, I love the grainy details. Rust is never very even in its colour, density and distribution. That should correspond nicely with the crystalline quality of the surface of rust.

The very last addition to our spec map will be our grime layer. Turn the visibility of the Grime group on and change the blend mode to Color Burn. I want this layer group to help create break-up and variation of the larger metal surfaces, so we need Color Burn's increase of contrast to help with that. Change the opacity to something in the range of 0.25, which gives us our finished spec map:

Now that we are done, going back over the project, a few things could be improved. Perhaps we could add just a touch of noise to the rubber spout base, to further break up the base (apart from what we have done with the layers of dirt, dust etc.). We could also make a differentiation between the exposed metal and the painted metal.

In general it is worth noting most, if not all, of what you need for your spec map, you should already have in some shape or form in your diffuse (colour) map. Also, a spec maps best friend is variation. So if you have large stretches of the same material on your geometry, make sure you consciously look to break it up in your spec map. Unless your object is fresh from the factory, this is a really key point. On a show I worked on, we had a number of spaceships, which needed to appear relatively clean and sci-fi'ey, but as a result the colour maps were struggling a bit to convey the needed realism - solution? Quietly make your spec maps absolutely filthy...
 
What is left now, is just to create a bump map and setting up our shaders and lighting. That will be the topic of the last two posts in this mini-series. Then you should have a render looking more or less like mine:

This tutorial continues with an overview of creating a bump map for our jerry can here.
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/Shameless Plug/

Ladies and gentlemen of the public,

Could I please prey on your patience and good nature for a moment:

Remember the stylized KFC commercial, I was using as an example for cartoony texture painting?


Of course you do.


That short is nominated for an award by Animae Caribe. Could I ask you, please, to direct your browsers to http://www.animaecaribe.com/vote-commercial?and vote for "KFC 40th Anniversary"?

I would be eternally grateful and happy to reciprocate with a solid favour, whenever you need one.

Thank you kindly!

Story Learnings - The Incredibly Addictive Power of Breaking Bad

Not since the days of Matador have I found myself so helplessly captivated by a TV series. I am of course talking about Vince Gilligan's Breaking Bad.

Sure LOST had its captivating moments of mystique in beginning, but once it dawned on me, that the creators also had no idea where the story was going, you emotionally disconnect.

My buddy, the excellent concept artist Cenay Oekmen, kept pestering me to watch it, as he relayed the storylines to me. It was not that I had never heard of Breaking Bad before. At the back of your head, of course you notice the distant thunder of the many, many awards rolling in, thereby adding the show to your mental to-do list of things to watch, as and when a convenient opportunity arises.

Then Danny Stack, from the UK Scriptwriters Podcast, went so far as to claim that Bryan Cranston, in Breaking Bad, delivers the best acting, bar none, in recent years (Daniel Day-Lewis included). That sure is a tall statement and a ringing endorsement to boot. So I had to see what the fuss was all about.

Conveniently Netflix offered a first free month trial, when recently launching in England and Breaking Bad was part of the library on view.

What I found, I was not prepared for.

The show grabbed such a firm hold of my person, that I was unable to wrest myself free of it, till I had watched it till the end. Frightened and fascinated of this stranglehold Breaking Bad had on me, I would write down observations on a notepad while watching, to help me analyze the powerful means of storytelling employed by the creators.

This is what I found.  

Tension

The tension, Breaking Bad produces in the viewer, is so strong, that it leaves you unable to break free from the story till the tension is finally released in the desired resolution. However the desired resolution never fully materialises, so you are always left hungry and never sated.

Once the desired goal seems within reach, something comes up: The Cat String Theory (a cat is only interested in that piece of string when it is out of reach) essentially.

The use of imagery in the opening sequence is very clever. Mysterious and ominous images are shown without any context beyond what the audience puts together to make sense of it. Some times consequences are shown before causes; some times the images are foreboding. It all increases the tension.

Shock is used deliberately and in clever ways. The effects of the shocks further increase tension and keeps your mind racing defensively at all times. The impact of the shocks are amplified through contrast: The brutality of the criminal drugs world is juxtaposed against the tranquility of domestic trivial family life.

Walt has a number of tension axes running through his life:

• Between Walter and Skyler runs an axis of smoke and mirrors, as Walt struggles to achieve his desire without alerting Skyler. Will he get found out, or will he not be able to carry out his plans for the benefit of his family?

• Between Walter and Jesse runs an axis playing on stupidity, as Jesse with carelessness inadvertently mess up everything Walt painstakingly tries to achieve with carefull planning.

•  Between Hank and Walter runs an axis focusing on both who can be the coolest father figure for Walt Jr., as well as their individual positions on either side of the law. With Hank parades his macho credentials as tough guy law enforcement officer, Walt is sorely tempted to reveal what a hardman his Heisenberg alter ego has become; A macho alter ego, Walt is openly in love with, as he finally releases all the frustration from the years of being an overlooked mild mannered chemistry teacher.

All of these tension axes, are like all the spinning plates an acrobat has to keep spinning simultaneously, or the whole act falls apart.

When Walt reaches his goals, he doesn't find deliverance, but rather more frustration. The frustration of 'why be King of the world, if nobody knows'? This mirrors his life-long frustration of being an incredibly skilled chemist labouring in obscurity in a dead-end job.

Empathy

Right off the bat, the audience thoroughly identifies powerfully with Walter White's desire because of the extraordinarily unjust plight of the protagonist. This is further amplified by how high the stakes are: Life and death essentially; his own, his handicapped son's and his unborn child.

Walter White and Jesse Pinkman is a classic "stuck with you" type of protagonist pair. They are mirror opposites and are reliving each others' lives in reversal. Yet they cannot see how similar they are; like a soon-to-be couple in a romcom, you feel like shouting out at them, "don't you realise you love each other?!"

Both halves of the protagonist pair, Jesse and Walter, are obviously well-meaning underneath their respective stupidity and brusqueness.

Our protagonists have their likability increased through plenty of "save the cat" moments.

Walter White only wanted a solution to his very unjust predicament when he started out. But now he is tainted and can never go back, which increases our pity for the protagonist's original plight.

Recurring Themes

The stakes will be raised by stating the goal, and then having accidents and unfair circumstances come in the way of the goal on the first attempt, whereupon dreams of ever achieving the goal are replaced with frantic damage control. 

The show dazzles a lot through really imaginative plot turns and clever use of chemistry (a bit like MacGyver) and science.

Recurring obstacles: Wife (and the rest of Walt's family) finding out, police, accidents, criminal predators and similar hazards, stupidity and naïveté.

The name of the protagonist (Mr. White) carries a lot of symbolism: A man who has hitherto never done anything illegal in his life.

Breaking Bad has a recurring themes of "good" people with "illegal" personal secrets; Skyler smokes while pregnant, and sleeps with her boss, while trying to impose morals onto Walter; Marie is a cleptomaniac shoplifter married to a law enforcement officer; Saul is a solicitor, who actively deals in criminal activity; Gus is an upstanding member of the community and a benefactor of the local DEA, while being a drug overlord etc.

Conclusion

All of these things are not particularly new; They have been part of the storytelling canon for ages. But the writing team and Vince Gilligan have employed these tools in absolutely expert fashion. I have never seen anything, before or after Hitchcock, where tension itself has been employed so effectively to hook in the audience for such long durations of time.