Illustrator: How to create realistic reflective gold surface?

Question

I'm trying to draw a realistic gold ingot. I've been playing with some basic shapes and gradients, but realism isn't my strong suit. I mean, it's obvious what it's supposed to represent but it just doesn't look realistic or professional. It's hard to know the angles to use and how the light falls on/reflects off the surface. And how to emulate the soft smooth rolled edges.

A gold ingot is like the traditional bars of gold bullion used for currency and stockpiling, etc.
Heres the basic shape:

Here i've just used the transform and extrude/bevel functions to create a simple, single layer pyramid stack and imply a third dimension.

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I watched and read a very nice Photoshop tutorial on the kind of look I'm going for. Shame it's not directly applicable to Illustrator.

Answer 1

I am naming these chapters starting with V as the second part of this post.

The first part has renders of 3D models, the second half of the post has vector based images.

Chapter V. Illustration

One thing that I was considering on my other answer on this same question is the premise that Illustration has an artistic interpretation that can or can not correspond to reality. That is a strong point of using an illustration over a real photo, or in this times using a realistic 3D rendering. So we need to keep in mind that.

Chapter VI. Gold Material

As you want a Gold ingot, we are assuming pure Gold, not a gold alloy, which can have different tints. Let's explore more in-depth the properties of gold from an artistic point of view.

Pure polished metallic surfaces reflect the surrounding environment. Gold absorbs a bit of wavelength producing the "yellow" cast.

Searching on some 3D rendering forums about this base tint, I found RGB values of R1G0.685B0.150 Translated into a 255 level RGB this is R255G175B38.

This means that a whiteboard reflected on the gold bar will not render white, but this tinted yellow. The final render has other values, because of the intensity of the illumination, the reflectiveness of the floor, angles, etc.

Chapter VII. Reflections

Remember that the tone we see depends on what is reflected on the surface, so, let's add some white panels to reflect them.

Normally an ingot is not polished. It is not jewelry. A real ingot has a sanded finished because this comes from the cast. I am using a generic "roughness" so it is easier to see (and to produce)

See how these sharp edges on the reflection start to blend. You can start constructing gradients on illustrator.

Now, look how the "direction" of the gradients represent what is, again, reflected.

To simplify the gradients more, I am simulating a more sandblasted finish. I'll go back to a more polished look later.

Chapter VIII. Bevel

We had a main light above the ingot all the time, but because of the stiff angles, the reflection was not in the correct place to be spotted. Now it is because the round border has many angles.

Chapter IX. More ingots

Now ingots start to interact. Between them, we now have a black face, because we are not reflecting the external ambiance.

But more importantly, notice how the faces orientated similar, act as segments of a single wall, having somehow consistent gradients with small changes between them.

Also, the ingot closer to the camera now reflects the one above it. This can start to get more and more complicated to simulate an illustration. But keep it in mind.

Chapter X. Surroundings

If I add a real-world ambient, it starts to get complex shapes on the reflection, and also, it starts to take the dominant color of the surroundings. The base material has not changed in hue or tone, I only moved the roughness to have more distinct shapes reflected.

This looks more orange because the illumination itself is warmer.

Remember, for illustrative purposes having a more reproducible gradient implies a less polished gold.

Chapter XI. Reflection on reflection

When I put two ingots that receives light between them the light starts bouncing, and the already yellow cast turns a bit more orange.

Chapter XII. Now the gradients on the vector program using mesh

(Work in progress) I'm arranging the screen captures.

1. Take some sample colors so you have a basic palette. You can use any color reference you have.

2. Define your basic shapes, one each face. And I am preparing the mesh fill. I am trying to keep it simple.

3. Play with the colors of the palette you defined earlier, of course, you can sample more colors from the reference image.

4. Put these mesh objects inside your basic shape (Clipping Mask)

This starts to look decent.

5. I'll add some shadow to see what is happening. Just some flat shapes combined.

6. Preparing now the bevels.

7. I strongly recommend that you make a flat bevel. This will simplify the process. A flat bevel is made exactly the same as the flat faces. Stop reading now...

8. Ok, want to continue the hard way...? These gradients are tricky. The exterior nodes are transparent to blend. The interior ones should be using colors that make a good contrast.

Play with the mesh. This needs some experimentation.

More tweaking of the shadow...

The final geometry is simple.

Some nested objects. It was all about gradients.

The result

Here it is. It can be improved, but like everything it takes time.

Answer 2

Look at images of real gold! I mean sure you can try to solve this issue with plain thinking. But truth is, gold has a very special reflective behavior.

The trick to gold is that its reflection is actually red in color, especially apparent in inter gold reflections (see above and this stock image). But be careful, not very many people can afford to have a photo shoot with real gold so many images you see aren't actually gold.

Image 1: Reflectance of gold

Answer 3

For me.. Gold has always been about using the proper palette for colors and then layering gradients on top of each other.

Too often people see "gold" as being strictly yellow when in reality the ore has a range of colors from yellows to browns and oranges. The more contaminated the ore is, the more brown it can get. Then throw in shadows and tonal changes for that and "yellow" is really only a base.

So I tend to set a palette for the base colors I want, then draw the base shape.. then layer various gradients, or other solid-filled shapes, on top that base shape.

Any actual "reflection" is all based upon a light direction or perhaps surrounding objects/elements. For the group of bars on the right, I added an additional highlight to the top of the bars, and darkened the sides of some bars since the stack itself would cast deeper shadows.

It's all sort of relative. However, you can typically use a range of yellows to brown and effectively pull off "gold". The actual object you may be rendering may be better suited for a more brown or orange "gold".

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Ultimately i've found there's really no single gold gradient that works no matter how you add color stops or the direction of the gradient, etc. Gold is a solid colored surface and any reflections/shadows are cast upon that surface. So using some gradient as an indicator of the surface is entirely correct in my view. If I wanted to add reflections/shadows to something like a phone or tv remote, I wouldn't start by applying a gradient to the base shape. The base shape would be a solid color, then highlight and shadows are built on top of that base shape.

Standard gradients as the base trying to show highlights and shadows all in one step really limit the appearance to a degree in my opinion. Gradient meshes can work well, however with meshes they can be come time-consuming to edit due to surrounding objects. I love gradient meshes, don't get me wrong. I use them all the time. However with layered highlights/shadows editing is much, much easier, at least in my world.

Answer 4

You have used something like "gold gradient" It's especially unrealistic if it's used on several surfaces. You should notice that polished gold is like a mirror, only a colored one and generally so non-planar that the image is extremely distorted.If there's bright lights, they should be seen at least on some rounded edges.

Color of gold:

That depends on how much it's diluted with other metals and with what metals. I skip the differences between the common standard mixes.

I have used in several occasions as my base gold R=191 G=170 B=117. It's not especially gold looking alone and it's far more less saturated than many horrors I've seen.

Do not rely on the screenshot, use the numbers! There are far too many color conversions between my Illustrator and your screen.

It starts to resemble gold when it's used to colorize a grayscale image. Here it's placed with blending mode Color onto a white to black gradient:

As well you can have the grayscale image on top with blending mode = Luminosity and the gold base color in the background can have blending mode = Normal. This can be more convenient if you must tweak the grayscale image for the right appearance.

You may wonder why so often gold has more saturated colors. Something like orange can be seen in some used gold gradients, too. That's because the light isn't always white. If it comes as reflected from other gold surface, it's already colored and the next reflection increases that filtering. That can be coarsely simulated by multiplying two of my gold gradients which have different directions:

It's not the full truth due the non-linearity of our color sight, but be sure, that a single hue gold gradient isn't enough if your image has gold reflected from gold, for ex. you have a bunch of gold ingots. To keep it simple you must include more orange areas to the colorizing layer. You can pick the colors from a multiplied pair of single hue crossed gold gradients, just like the example. It's easiest in Photoshop.

Illustrator's 3D effects can create to some degree right looking shadings. They have wisely named the most glossy mode only to "Plastic Shading", so nobody should be disappointed, if he got no gold. But by careful light setting something acceptable can appear. Here's a rounded but otherwise quite random piece extruded and shown in 2 different angular positions:

As you see, it's really plastic, there's no shine. Illustrator hasn't good tools for tweaking the brightness and contrast. One trick is to add a dark grey low opacity overlay with blending mode "Color Dodge"

If you want glossy gold, you must insert the reflection by yourself. Many surfaces can have gradients, but we use also something else. At first the gradient:

A bended sheet has highlights at obvious places. There's a grayscale gradient giving its luminosity to a base gold version.

If you have dark shades in the reflection, the environment also must contain much dark Against white background this would seem dirty

Beyond gradients:

You can use also blurred black and white shapes instead of gradients. It's not totally different, it's an alternative way to implement gradients.

In a complex environment you can reflect it. You should study how the environment reflects from chrome parts of a car. At least GIMP has chromium filter which takes a photo and make chrome-like distorted mirror images. With gold you need only the coloring as extra.

The gold ingot:

It has certain forms for easy mold casting. The surfaces are tilted and most edges are rounded. I sketched one in 3D:

This is a screenshot from entry level freeware CAD which definitely cannot make gold nor other material renderings. But the wireframe shape can be exported as 2D PDF. It can be opened in Illustrator:

I colored with the shape builder areas which need different colorings for gold. Grey areas can be solid greyshades or gradients. Brown areas must be gradients and they are most probable places of glossy highlichts.

If one thinks a moment, he sees that Illustrator's linear and polar gradients are too simple. One needs gradient meshes. They are complex and filling them succesfully to metallic glosses needs incredible amount of skill and patience.The job simply is beyond the possiblities of a beginner. But blurring is a way to cheat.

The wireframe of the ingot must be filled with the shape builder two times. One for the outline of the ingot and the other to get a base frame for blurs.

The latter needs some help lines. Actually it's like an ingot with no roundings:

One must decide the light. It fixes which greyshades are used as fill colors . The gradients need auxiliary white and dark lines at the edges. There are also seemingly uunecessary outline strokes added to the grey areas. They only make the shape bigger to compensate the thinning at the edges which is caused by the blurring.

My final base frame before blurring:

All is grouped and gaussian blur effect is applied:

We have the other filled wireframe which is the outline of the ingot. In the next image one copy of the outline is used as clipping mask for the blurred shape. Another copy is colored to base gold. It will give the color to the clipped shape:

The colored shape needs to be placed on the blurred shape with blending mode color. The result=a gold ingot:

It's not perfect, but well in the range of a beginner. You should notice that you do not need 3D program in any phase for this. The 3D wireframe was only a reference. All used shapes are easily drawn by hand.

Shape builder must be thoroughly studied before this.

One can want stamps or texts on his gold:

Illustrator's 3D extrusions can be useful. Here is actually extruded a hole ABC. The greyshades are set manually to fit. The inserted shape is in the right.

Rendering in a 3D program can create photorealistic results. They do not come out from simple software nor intentionally limited free versions of commercial programs. Here's an example: It's an old try-it-yourself version of Keyshot:

I have no way to force the bars to be considered as single continuous surfaces. If the surfaces are glossy, there are visible seams between the curved and planar faces. I bet competent Blender users would laugh for this. But one thing is shown plausibly: Gold reflected from gold has more full color, as told above.

Handcrafting in Photoshop:

Photoshop offers more flexibility than Illustrator. It's layer styles help to create glosses and shadows. An example:

It originally had the dark grey background, three layers for three visible surfaces and a coloring layer.

Surface layers were filled with different grayscale gradients to mimic environmental reflections. The fill areas were selected with the polygonal lasso tool, no vector paths were drawn

Each surface layer got layer style Bevel&Emboss to create the glossy and dark edges. Often the same effect is used to create also the surface wide gradients with extreme settings, but here only the edges were affected.

The coloring layer was filled with base gold and then faint orange were sprayed to areas which are dark in surface gradients

Bevel&Emboss edges fight at corners. One can insert layer masks to decide who wins who and where. I merged all and painted the corners with the cloning brush. It's a little grungy, but I see it usable.

Answer 5

I will try to keep this as simple as I can.

I. Watch references. This alone will give you a quick answer if you watch carefully.

II. Seek wisdom on my related posts :o)

Prototype Visualization: How can I learn to render glass convincingly?

What should be the right approach to master Adobe Illustrator for beginners?

III. Now some explanations. Ready?

Let's start with... not a gold ingot, but a chrome sphere, on the classical scenario for a chrome wheel illustration. A desert.

1. I have a quick gradient but you noticed that if I do not have a sharp edge, this is just muddy.

2. But if I have a sharp edge, things start looking like reflected on a polished surface.

3. But I need to consider the shape, so to add the illusion of a sphere I will put this oval inside the circle.

4. That is better.

5. I add a hotspot, probably the sun.

6. And here is a small detail. There is an effect called fresnel, this basically means that the reflectiveness depends on the angle... but that is too geeky for now. Just consider this gradient to give more volume.

7. But if you already read my other post, you learned that what is on a reflective surface is not the object itself but what is around it.

8. The more details on the surroundings, more details on the reflections.

IV. Now let's apply that on a gold ingot.

Here is a gradient similar to yours... but in an angle. There is no need to keep it straight.

But look what happens if you stack one node of the gradient next to the other. There is now a "sharp" reflection, that looks more "chromed"

You can play with these nodes. You do not need many of them... In fact you just need this few.

V. The shape.

Of course, you can start with this, instead of the gradient. Look the rectangular shape... simple gradients. I'm too lazy and using the same on two faces.

An ingot is not a razor, the borders are rounded. For the bevel, again simple gradients. Probably brighter than the flat face (remember to see references)

Do not use the exact same gradient on all ingots... I am lazy and used the same but rotated among them. Sorry but I added perspective to my original ingot... I should have leaved it isometric...

Between the stacks of ingots add a darker gradient.

This is a basic tutorial. But you could keep pushing the "realism".

P.S. I am not using Illustrator, but Corel Draw, but it is the same idea.

I will post a more real ingot later, with less fake gradients.

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Method 2... I should have done this one first...

Play with the mesh fill...

It's more fun!