Creating looks

[Gare]

Here’s a second way to make a chrome sphere; I used Xara and you can download the source file to examine; the Illustrator steps are very similar. You begin with an image that has that “sky/horizon/gound” layout I discussed in the previous post. The you put a circle behind it, select both and then use the Arrange--> ClipView feature to clip the image to the circle—much less hassle than simplifying the image with a Boolean Intersection. See callouts 1 and 2 below.

Then it’s shading time. You create a circle with a circular gradient from white to black (as the endpoint). Put the white start point at upper left. Then you give this shading object circular transparency 100% at the start point and about 40% at the end point. Use Stained Glass mode (Multiply mode in Photoshop and other apps, same difference). Create some highlights using white ellipses in Bleach mode transparency (Screen mode in other apps), and then use just a little feathering. Although technically chrome has nice sharp, tight specular reflections, when you illustrate it, it looks wrong (or artificial) without blurring the highlight edges just a tad. Callout 3 is the shading group of objects, callout 4 is the finished chrome sphere.

I’ll be back soon to talk about creating metallic reflections on surfaces that aren’t spherical (thank gawd!)

My Best,

Gare

[ronmatt]

Gare, that's a great effect. I was pretty pleased with the way I've been doing this exercize, but I've actually learned somethin new that I can and will use.....thanks

But I'll attempt it in PS. 'cause even though I have Xara, well, you know.

[Gare]

You're welcome, Ron--

I was beginning to feel that I'm posting all these min-tutorials to a graveyard! Almost 200 views, but only three replies!

If you or any other members would like to post tips or short steps for making material looks, please wail away. This is a two-way forum.

By the way, a very quick 'n' easy way to horizontally warp your base horizon image is to use the Warp feature while in Free Transform mode in Photoshop. I like to play with the image in the Liquify filter d'box for a little more hands-on, but either way it works and Free Transform loads quicker than Liquify. I got a tip for Liquify: create a selection of the area you want to distort before entering the d'box or PS will idle for a while to calculate the entire layer. This is true of most of the filters, even when you have a box with a lot of RAM. It's not your machine; it's the way PS processes.

I'm going to post a tutorial on shading a non-spherical shape using a reflective metallic treatment. I'll show how to do it in a modeling/rendering app, but also discuss how this look can be illustrated 2D style in Illustrator, PS, Xara and so on.

My Best,

Gare

[Gare]

I've built a lot of environment maps for use in 3D programs over the years, but basically rely on three that work in "general purpose" scenes (where an environment is not specific to the content of the scene). I use the map of the purple skies and the green hills in the earlier post, and also use the two attached. The top guy here is just a drawing of a photo studio lighting setup from an object's point of view, with bounce cards and stuff, all spherized a little to further distort the highlights on a curved surface. I keep the reflections grayscale because colored reflection are often unrealistic and they detract from the composition, creating unpredictable elements.

These images can be used to create reflective spheres as I've posted, but also work with 3D models.

If you need a quick, "dirty" environment, I recommend Vue D'Esprit. Just set up some clouds, a horizon and a ground and render to decent quality; you don't need an image larger than 400 by 300 pixels to get some decent "business" in the reflecting object.

My Best,

Gare

[Gare]

I tried out the demo version of modo 201 a few weeks ago, and the programmers—mostly defectors from Lightwave—have put as good a rendering engine in their program as the modeler. I watched the tutorial videos and was amazed that the rendering engine can “see” bounce cards you put in a scene. If you’re unfamiliar with bounce cards, they’re used by photographers in a lot of lighting situations to fill harsh shadow areas in a scene. But photographers who do silverware and jewelry photography use white cards and black cards extensively to “paint” a scene because silver is highly reflective and a typical studio environment would look lousy bounced from the silverware.

What the clever people at Luxology did was to set up a scene of a futuristic sink and faucet with an accordian-style room divider behind the camera with alternating white and black panels. Cameras in modeling cameras don’t photograph themselves as they do in real life, so with a little positioning, the faucet looks incredibly realistic IMO because the same lighting and bounce cards as you’d use in real life were used in the scene.

This has got me thinking and in future posts I’ll show how to apply this technique to both modeled scenes and illustrations.

My Best,

Gare

[Gare]

Okay, enough with the shiny metal spheres; let’s get into metallic surfaces you see everyday that are only slightly curved or even flat. Suppose you’re photographic a brand new spanner wrench; I modeled and rendered one in Cinema 4D a few days ago because C4D’s rendering engine is optically correct, hence, the renders look quite photorealistic. You usually wouldn’t photograph the largely flat wrench head-on, mostly because when you pose a still life scene, one-point perspective is visually, compositionally boring. Stuff looks like Post Office Wanted posters—you need at least two-point perspective (front and side showing) and three-point perspective (front, side and top) visually describes objects in the scene the most completely.

What you can see happening with the spanner is that the environment looks a little blurry and quite distant; I used the environment map at the bottom left of the image. From an artistic viewpoint, this is good because not only does the reflection look accurate, but it doesn’t predominate the objects in the scene—you have to be careful that the “fill” of an object doesn’t steal from the silhouette. Some additional business I added to the scene is dichromatic lighting—a red light from beneath and a faint blue light from above. This is good lighting to suggest the strength of metal in an image—like it came out of a forge or something, very masculine. Look at the shading, and in my next post, I’ll show how to simulate this metallic look in an illustration. I did a Xara and an Illustrator file for you to download and play with.

My Best,

Gare

[Gare]

In my previous post, I show a spanner wrench whose metallic surface shows soft, dappled highlights and shadows. These are simple to recreate in an illustration program—you just draw some blobs and then feather the edges. Also, there’s a gradient or two going on; this, too, is easy to reproduce by using a multi-step gradient—you can do it in a drawing app or in Photoshop. If you’d like to download Spanner.zip(it's a PDF file that'll open in Illustrator CS 2 or later; the darned Illustrator file was too large to post!), it’s attached below along with the same file in Xara format. Basically, a realistic metal surface has swooping shadows and highlights in some areas, and then soft and hard color transitions. What you want to do is this:

1.  Add a gradient to both pieces of the wrench…make a slow graduation to keep the surface visually moving a little. All objects show lighting fall-off.

2.  Create some blobs and then feather them. Additionally, you’ll want to add a little transparency to keep the surface’s contrast from looking too harsh and unrealistic.

3.  Create a piece that has a multi-stage gradient in it.

4.  To add a little more realism, in my illustration below, I've got the spanner on a piece of wood. To make the handles look as though they're reflecting some of the wood grain, in Xara you can use a Fractal clouds fill at partial opacity--the real trick to getting streaks is to squash the vertical fill handle when the Fill tool is chosen. Alternatively, if you want to use Photoshop, there's the Filter->Render->Fibers that works quite well.

5.  Group the objects, and then use your application’s clipping feature: in Xara, it’s Arrange->Apply ClipView, in Illustrator it’s Object->Clipping Mask->Create, and in Expression it’s Objects->Clipper->Make with Bottom Path.

6.  Add some shading to this drawing. Shadows, highlights, any thing you can do to integrate the surface shading with other shading.

PIXAR does some interesting stuff with "data amplification" that I'll show next.

My Best,

Gare

[Gare]

Here's the finished piece. I'm not 100% happy with it because there's a little too much contrast between the surface and the object, making it look less than realistic.

If this happens to you in your work, try decreasing the overall contrast, or selected areas by Quick Masking in Photoshop. Although the pros eschew Brightness/Contrast Adjustment to Curves, Brightness/Contrast still has creative uses.

My Best,

Gare

[Gare]

Alvy Smith, co-founder of Pixar, developer of the graphics alpha channel and the HSB color model, coined a term for adding complexity to synthetic images—“data amplification”. In principle, the idea is simple; the world is a visually complex place, as are materials (such as the weave in fabric, the dust on a surface, and so on), therefore the more visually complex you make an illustration, in theory, the closer it comes to realism. However, you need to be very careful in the type of “garbage” you add to the surface of objects—just adding “stuff” or “business” as they call it in films doesn’t necessarily bring you closer to your goal of photorealism.

What Pixar does sometimes in their movies is to build a shader (a material with reflective and other attributes) that adds visual complexity in an aesthetic and mostly realistic manner using a mathematical recipe, called an algorithm. If an algorithm can add visual complexity, you can ease off on the massive processing time it takes to accurately calculate reflections via ray tracing. After examining a Pixar shader for reflective metal, I realized that the algorithm is very close to something called a “caustic”; the best visual example of a caustic is the ropey, meandering blobs you see at the bottom of a swimming pool.

So I actually drew a caustic seamless pattern based on a mathematical example I rendered out of a texture processing app. I tweaked it a little as I did a few renders of extruded text to get what I considered to be interesting results. And I’m attaching it in PDF and Xara format for anyone who’d like to use these drawing in illustration pieces or modeling. In the attached picture below, you can see a render out of Pixar Typestry (a), my caustics drawings (b), the caustics used as a straight fill in Microsoft Expression Graphic Designer, and the grayscale version of the caustic mapped onto some extruded text. It indeed provides the “business” needed to suggest reflective metal.

My Best,

Gare

[Gare]

Here are the example files.

My Best,

Gare