Exploring Shine

This week I had a quick look at painting and drawing shine on objects. Last week’s “Coastal Shiner” painting picked up some shine the simple way, by just drawing exactly what is there. But it got me thinking about the mechanics of shine and reflection and wondering what rules make the patterns of light that I see in glossy objects. The way light reflects from shiny, wet objects is so fascinating but I only know the basics of how any of this works. I can feel the pattern behind the reality of what I see but find it very hard to formalise it into workable rules for painting.

I began with some basic sketches in my sketchbook…

I was playing around with how reflections sometimes show some of the local colour (or in the case of pencil sketches local tone). I found it very hard to get these sketches to read as if the two animals are wet, although the frog’s eye works to some extent.

A deep glossy shine is basically a reflection so it very much depends on the surroundings of the object. In the right light a reflective surface can look absolutely marvellous. But I wanted to know how to simplify this effect we see in nature so as to capture it in a painting in it’s simplest form. I played around with some gouache and watercolour paint on regular copy paper to see if I could find some basic rules. Here’s one of these trials…

It’s more than just the highlights – there are colour reflections between coloured objects and lower light reflections too.

So, my first step was to simplify all of this down to low light reflections and high light reflections and had a go at painting a beautiful little creature called the Spotted Salamander (Ambystoma maculatum).

I painted his body black and then added some grey highlights and some white highlights like this…

It’s not quite there but does read as a little bit shiny (if you squint a bit!)

Then I decided to paint some wet rocks in a stream. I tried to abstract things a little here to see if the basic reflection rules I’d made would go that far…

Again it reads as water but isn’t quite there yet.

I decided that this is something I am going to have to study for a while to really understand.

After reading around I found out that modelling light on objects is called an Illumination Model. In fact there are a number of different models to chose from. The more advanced the model, the more factors are taken into account and the more accurate the surface rendering is when compared to real life. This field of study began with the study of optics during the enlightenment and continues today with the huge advances in computer generated images.

For example a very basic model is called the Lambert Model which was figured out in the 18th Century CE. In this model all surfaces are uniformly matte and reflect light to the viewer according to a simple geometric law (the cosine law). It sounds complicated but really it just means that if an object is illuminated by strong directional light (like light from the sun) then the intensity of the light reflected from it varies with the angle of the object surface to the light. If the surface is perpendicular to the light source then the intensity is maximum. If it’s at an angle it’s less and the steeper the angle the less light gets reflected. This model gives us a basic understanding of illumination but is very far from being accurate.

A more accurate model is the Phong Model, from 1975, which combines three types of lighting effects…

  1. Ambient light – caused by light bouncing around a volume randomly in an atmosphere. This light is low level but the same everywhere. (Interestingly, this lighting is almost completely absent in space which is why spacecraft look very different on earth compared to when they are out of our atmosphere.)
  2. Then there is diffuse lighting which is similar to Lambertian lighting and illuminates an object at each point according to it’s surface angle to the directional light source.
  3. Finally there are specular reflections. These are mirror like reflections of a light source on the surface of an object. In Phong’s model these are white highlights but in more advanced models you can adjust the shininess of an object to get more or less specular reflection from tiny white highlights to a full mirrored surface, like chrome.

Anyway, I’m going to read into this a bit more to try to make an illumination map in my mind for my painting. Only time will tell if this helps at all!

Sculpting with Paint – Tiny Gouache Portraits

 

This week I did some solid painting practice.  I wanted to improve my ability to paint directly with no drawing and to render 3D shapes using the paint.  Since faces are such an odd and challenging shape I thought some portrait practice might be good.  I split up a piece of A4 watercolour paper (Hot Pressed) into 4 and taped each piece down…

 

Then I gave myself half an hour for each one.

I began by painting the mid tone and then the dark.  Then I added the light tone.  I made three tones for each colour and mixed and blended them on the paper.  I wanted a rougher look so I stuck to my restricted time which forced me to accept a lot of imperfections.  I tried to be very varied in my colour choices.

For the first sketch I used complemetary colours, orange and blue (my favourite combination)…

 

My second picture was more purple and yellow…

 

(I had the lady’s coat in purple too originally, but I found that it dissapeared into the background leaving me with a floating head(!) so I changed it to red.)  I find painting very smiley faces quite difficult but this lady looked so lovely and cheery that I couldn’t resist.

In my next picture I used analogous warm colours to give more restful effect as the lady in my reference photo looked like she was meditating…

 

For my last sketch I allowed myself to paint a Jedi!!!  I went with a more monochrome feel but in blue so the whole thing was quite cool…

 

I learned quite a bit from this exercise but it’s difficult to put what I learned into words.  It’s the kind of learning that stays in your hands and eyes and doesn’t really need language except if you try to write about it!

 

Rendering Clouds and Rhinos

(N.B. I create and schedule all my posts ahead of time in the school holidays and then just make minor adjustments before they are posted by the WP system. Unfortunately I am quite unwell at the moment and waiting to see if I need surgery so I can’t do this right now. Instead, I’ve decided to just let the system publish my posts automatically without the extra editing I usually do just before they go out. I apologise for any errors and for any problems I have getting back to people who comment while this is going on.)

My Quirky Friend

This week I played around a lot more with gouache. When I first tried this medium, a year or so ago, I found it quite tricky but I don’t think it’s actually difficult, it’s just quirky and idiosyncratic. Once you get to know it, it reveals it’s fun side. I guess it’s a bit like having a quirky friend. They might seem a bit odd at times but once you know them you see how lovely they really are. I really love friends like that!

The Joy of Totoro

So I began this week looking again at how different painters render clouds. I should really have gone straight for Monet’s The Seine at Argenteuil but I’ve recently been re-watching a lot of Hayao Miyazaki’s Studio Ghibli films and I was really caught by the background artwork in My Neighbour Totoro. I wasn’t really doing a serious study but just sketching in my regular sketchbook. I was just full up with the joy and beauty of the film itself. This is what that sketching turned into…

I didn’t really get the cloud colours right, or the shapes for that matter but it was so much fun playing with the paint and re-experiencing the joy of the film through sketching! I worked from back to front in the picture so I could put the next layer I was working on over the edge of the previous layer.

Rhino Studies

Later on in the week I began thinking about Rhino’s and how they’re heading towards extinction. They’re magnificent, strong animals but can be unpredictable and cantankerous. Although I wouldn’t want to go down to the pub with a rhino, I kind of admire their fierce “sod-you” attitude. So I painted a couple.

I began with this one…

Which looked like this painted…

I liked the deep colours. Gouache gives a painter such a range of strong colours it’s tempting to use really saturated hues all the time just because you can. On reflection I thought my rendering here made the skin look more like that of a hippo, sort of rounded and slimy, especially up near the ears. So I had another go and this time I went for more realistic colours so I could concentrate on more subtle shades and hues.

Here’s the sketch…

I used an under-painting on this to get my eyes around the main darks and lights…

Then I went for the final picture…

I was using this study to practice rendering 3D shapes with paint and to learn to use more muted colours and shades. I am happy with some of it and would like to work on other bits a bit more next time. I like the shape just behind and under the animal’s eye, where the face has a concave look because of the bone structure. I was also pleased with the hints here and there in the shadows of the range of violet and blue shadows I was using in addition to the shaded local colour. On the other hand I’m not that keen on the ears or the bottom of the front horn. Neither of these parts of the image scan as well as I had hoped.

Learning Curves (Caution: maths fun ahead)

I’ve been painting for most of my adult life now. I wonder if I will always have things I would like to change next time in the work I produce? I’m aiming to get each picture just how it is in my mind, but they’re always a bit different. Wanting to paint a perfect picture feels a bit like trying to approach the speed of light. It’s fairly easy to make progress when you’re a beginner but the better you get the more energy it takes to improve. It’s like the graph of 1/x. As x goes up, y gets closer and closer to zero but never gets there, like this…

In fact I think with art it’s more like this brilliant graph of a curvilinear asymptote…

How cool is that!

I really hope the learning never stops, I love the ride on this mad slope.