Draw Your Own Conclusions

Tom Beeley shows you how to go from bitmap to vector and turn a photograph into a Draw file

If you are a beginner with RISC OS Draw, or if you could do with some extra experience before tackling this article, take a look at the separate introduction to Draw on this CD. As well as working through Draw's basic features, it has some exercises to help you get started with tracing simple objects.

Turning your photographs into drawings

The original photo	The traced drawing

You may well ask, "why not use the actual photograph?" That's a good question, and there are really several good reasons why you may prefer to use a vector drawing rather than a sprite. Not least is the great saving of memory, especially if you want to when repeat the graphic several times on an A4 sheet of card, or perhaps have it occur more than once in your basic design. Another very good reason fo using a vector graphic is that it can be scaled to any size without becoming blocky.

Having been convinced that there are advantages in tracing a photograph (or part of a photograph) or scanned image to produce a Draw file, read on!

You are going to need a great deal of patience and persistence in order to create your own personalised Draw files from bitmap images if they are to have a lifelike appearance. What follows is the method I used to trace from the photograph that I took of my Volvo, as shown above. It is not necessarily the only way to do it, but it is my way.

I took a digital photograph of the car when it was standing on the garage forecourt before I bought it. I then used Photodesk to eliminate the other vehicles. This wasn't an essential step by any means, but removing the extraneous bits did help me to concentrate on the one car when performing the tracing. Here is the picture before and after manipulation in Photodesk:

Before	After

As you can see, it is a white Volvo; however, so that it would look more realistic when printed on white paper, I needed to fill the 'white' parts with a very slightly off-white colour, and the line colour had to be made a slightly darker shade still. I shall explain all that in due course, when I hope you will have a go at drawing it for yourself. However, you could have a different-coloured car at the click of a mouse if you wished. You can't do that with a photograph!

Because some users may find it impossible to load a JPEG into their version of Draw, I have changed the original JPEG into a sprite within the Draw files on this CD. It remains an image of sufficient quality to allow a good tracing, though. To produce a vector drawing of the quality shown above, you will need to exercise all your powers of concentration, and the need for infinite patience (or perhaps it is persistence) cannot be over-stressed!

With such persistence, you can produce a drawing of 'professional' quality; or, perhaps, if you lose patience and get only part-way through the task, you may still be happy with a drawing that is not quite so realistic. Like most things in life, you get out only what you put in! What will make your drawing lifelike will be the attention you pay to getting the fine detail right. I am sure that your reward for making a sustained effort will be great satisfaction in the knowledge that you can create personalised clip-art which equals the best that the professionals can produce. Because Draw is the most powerful free vector drawing program on any platform, the only cost to you will be your time and concentration. Remember, the quality of the finished product lies in the detail!

What follows is an explanation of how I created the Draw file. You may wish to follow the same steps. To prevent heartache, I kept to the golden rule, and suggest that you do the same: save the drawing after each successful step!

Clicking on the screenshots of Draw files in this article will cause the original files to be loaded into Draw, and you may also access the files by using the icons to the right. However, it is intended that you should use Draw to create the objects yourself while following this tutorial. No cheating, please!

1. The photograph was loaded into Draw, ready for tracing (see figure 1). Note that recent versions of Draw can load JPEG files (as produced by digital cameras etc.) directly, but earlier versions (on machines running versions of RISC OS before 3.7) may not be able to do this. To give users of such machines an easier way to start, the Draw file linked to figure 1 contains the Volvo picture as a sprite rather than as a JPEG. However, subsequent figures still contain the JPEG version of the image.

   Figure 1

2. I Selected a drawing tool first, then changed the line colour to yellow. I chose yellow because it stands out on the darker picture, allowing me to see where I had traced. I then began tracing!
3. The larger parts of the car were traced first, and here's a tip: when following the line to be traced, I tried to keep the number of clicks to a minimum, as I found it easier when I came to adjust the shape or position of the lines. I realised that I could always add a segment later if necessary. I also found, when tracing the smaller sections in particular, that I needed to increase the zoom factor, so that I could see the orange and blue control points more clearly and select them more easily.

   I selected the enclosed curved line tool and traced roughly around the body of the car (see figure 2).

   Figure 2

4. Here I needed to set the zoom to 2:1 or 3:1 before editing the line. Then, using the Adjust button, I clicked anywhere over the object I had just traced, which put me in Edit mode, and I was then able to change the line shape or its position by Adjust-dragging the appropriate control point until the outline followed the edge of the part of the body I wanted to trace. I saved the file when I had reached the stage shown in figure 3.

   Figure 3

5. The next three parts of the car to be traced were the remaining white sections which had not yet been covered (the strips between the windows, the front part of the roof and the mirrors). I used the enclosed curved line tool again. As with all the objects, I traced around them roughly first, using the minimum number of control number; see figure 4. Note that figure 4, along with subsequent illustrations, highlights the newly drawn additions by showing them in cream (with the existing shapes in yellow). This is just for clarity; the Draw files linked to the figures contain only yellow shapes.

   Figure 4

6. As in the previous step, I zoomed up a little and then, using the Adjust button, edited the lines until they followed the edges of the side windows, the white part of the roof and the mirrors as closely as I could. The result is shown in figure 5.

   Figure 5

   The idea of drawing the larger areas first and the bits that fit on top after them obviates the need to move sections to the back, although there are still one or two parts of the drawing that will have to be moved to different positions in the stack. This is because the position of any object in the stack is initially determined by the order in which it is drawn (i.e. an object drawn second will appear in front of the object drawn first). This can be changed, but to do so is sometimes awkward and I therefore avoided it where possible.

7. I continued using the enclosed curved line tool to draw roughly around the area of the sun-roof, then again Adjust-dragged the line to its correct position.
8. Still using the enclosed curved line tool, I drew roughly around the black strips that run down the side and front of the car, ignoring the number plate. The number plate was to be drawn and filled later, and would therefore cover up part of the black strip that runs across the front of the car. I then drew around the two black strips down each side of the windscreen and around the air vent below the number plate.

   When I had edited the lines to fit more closely, the result appeared as in figure 6.

   Figure 6

9. Tracing around the darker areas, as shown in figure 7, was the next move. These included the badge and cross members on the radiator grill, the door handles, the mud-flaps (front and rear) and the windscreen and headlight wipers.

   As these objects were going to be filled later, they were again traced using the enclosed curved line drawing tool. I edited the objects carefully; for example, I sharpened the point where the front and rear mud-flaps meet the tyre and the body of the car (see figure 8).		Figure 7
   		Figure 8

10. The next step was to trace around the headlights and radiator grill, as shown in figure 9.

    Figure 9

11. Drawing in the lines to show the door panels (using the open curved line tool this time) was the next task. I then traced around the shadow on the driver's side front wing and the top of the bonnet (see figure 10), and the shadows above and below the door handles (using the closed curved line tool again).

    Figure 10

    I was as accurate as I could be, never forgetting that the secret for achieving high quality results rests in the detail. This became very clear as I got to the more intricate sections like the radiator grill and the wheel trims.

12. Before setting out on those intricate tasks, and still using the closed curve tool, I traced round the objects to be seen through the windscreen and side windows, such as the steering wheel etc. (see figure 11).

    Figure 11

    I kept saving my work after every step!

13. The next part required an awful lot of patient attention to detail. I needed to zoom to 5:1, because the area to trace was a rather small part of the whole vehicle. Yes, it was time to tackle the wheels and, in particular, the wheel trims. Again, I traced roughly at first, using the smallest number of clicks possible, and edited the lines to make them follow the shapes more accurately (see figure 12). Changing the line colour would come later, as would filling the small spaces in the appropriate shades.

    I then began to realise what a time-consuming task I had taken on; but "Rome wasn't built in a day," and neither was this Volvo!

    Figure 12

14. figure 13 shows how the front wheel looked when it was finished.

    Figure 13

    Each orifice in the wheel trim comprises two or three separate objects, and they all rest on top of the elliptical disc. The central boss is comprised of two ellipses, enhanced with short curved white lines to give it a 3D effect.

    To avoid problems of stacking order later, I thought it is wise to draw the objects in the order that they appear: i.e. beginning with the object at the back (the tyre).

    Using the circle/ellipse drawing tool to draw the tyre wall, I fitted it as near as possible to the lines on the photograph, then edited it to fit accurately. Then, with the same tool, I drew the wheel trim disc and, after that, the two centre bosses on the trim (the larger one first). The tread was added later (see figure 14).

    Figure 14

15. Now the time had come to complete the detail on both wheel trims by tracing carefully around each area of light and shadow on the edges of the wheel trims, so they may each be filled later with different shades of grey. Look again at figure 14.
16. The radiator grill was the next area to be traced. Having completed the outline of the cross member and the badge, the grill itself had to be done. I zoomed to 6:1 before tracing around one 'inlet'. I then copied it and moved the copy along the grill so that it fitted over the next one, then I repeated this process, resizing and re-aligning as appropriate until I had gone all the way across the grill (see figure 15).

    Figure 15

17. Having completed the grill, I turned my attention to the badge and to the reflector on the front wing. Both of these required the use of text. On the badge, which I tackled first, it was contained within the symbol (see figure 16).

    I drew the two circles, the arrow and the rectangle first. Having changed the line colour to white, I then typed the word "VOLVO" over the top of those objects in Homerton font. Note also the shading above the badge and along the top of the cross members in figures 15 and 16. The reflector embellishment (figure 17) is the word "Volvo" typed in Trinity Medium Italic, changed to white and rotated slightly to fit as shown in the figure. It is not exactly right, but it produces the right effect. I chose to leave the number plate blank.		Figure 16
    		Figure 17

18. The penultimate bit of tracing was necessary as an aid to getting the grading right later, and so making the headlights look realistic. I traced them (as shown in figure 18) in such a way that, when the grading was done, they would look as though the sunlight was lighting up the headlight reflectors (see figure 19).

    Figure 18	Figure 19

19. The final piece of tracing was to put in the shadows in two places (see figures 20 and 21).

    Figure 20

    Figure 21

20. Having now traced around all the areas of the car that I needed to 'copy' from the photograph, it was time to take away the bitmap template and do some line- and fill-colouring on the vector outlines that I had so patiently constructed. Yes, I selected the photograph alone and deleted it! The result was figure 22.

    Figure 22 (very hard to see!)

    I was now working on a white background, and yellow was no longer an appropriate line colour, so I performed a Select all operation and changed the line colour to black, as shown in figure 23.

    Figure 23

    I then selected various objects and began to turn their outline frames into solid-looking shapes, and the car began to take form.

    First of all, I filled all the 'white' bits, but with an off-white shade in order to make it stand out on the white background. The mix of RGB that I used for the main bodywork was a setting of 95% for each of the Red, Green and Blue colour components; in other words, a very pale grey (95% white). This is another good reason reason for turning your photograph into a Draw file: you can 're-spray' your car in any colour you like at the click of a button and at no cost whatsoever! The line colour was slightly darker, at 90% for each of R, G and B.

    The grey shades go darker, of course, as you reduce the R, G and B percentages; so setting them all to 100.0 would result in a white line or fill, and setting them all to 0.0 would give you black. By altering the values finely you can make very subtle changes in line 'blending' and shading, especially if you choose the right shades when grading between two objects. (Note the grading of the headlights.)

21. Now I had the solid body of the car to work on, and I merely added fill colours and made subtle line colour changes until I was satisfied that the whole thing looked solid, as a Volvo should look. I did add a few extra refinements which I thought would improve the car's appearance, but I'm sure I don't need to go into any great detail for you to be able to give the vehicle your individual treatment.

Finishing off

I think that the headlights add a little realism to the finished product, so here is an explanation of how they were done.

The original shape drawn inside the nearside headlamp is shown above, in figure 18: I took this shape, copied it (so that I knew both shapes would have the same number of control points even if I dragged them into completely different shapes) and then made the copied version smaller. I knew that the original object would grade from the back into the copy, so I set both fill and line colours of the original object to 73% for each of R, G and B, which is a mid-grey, and the fill and line colour of the copy to white (i.e. 100% RGB). After re-positioning the copy as shown in figure 24, I grouped and graded them (100 gradations). The result is shown in figure 25.

Figure 24

Figure 25

There are several other places on the vehicle where I have added grading for effect. If you wish to know what shapes or colours (or shades of grey) I have used, this is how you can find out:

To make the car's windows look effective, you will need to draw two objects to cover the windscreen, side and rear window spaces, as shown in figures 26 and 27. Having set the fill and line colours appropriately, you must put them to the back, using the Select>Back menu option. The other grey shades (darker and lighter) will sit on top.

Figure 26
Figure 27

I am sure that I can leave you, now, to complete the final trimmings:

• Add shading on the wheel trims etc. by colour filling and changing the line colours to match;
• Make the subtle line colour changes on the bonnet and to fill the shadow on the bonnet and wing;
• Superimpose the grading where necessary, such as above the wheel arch, in the headlights and side lights, and particularly across the top of the windscreen, where a touch of colour has been introduced;
• Colour-fill the small reflector on the front wing.

You know how to find the colours or grey shades that I used!

I am sure that there are one or two areas that I haven't mentioned, but I suppose that this attention to detail could go on for ever; or so it seems! Well, you were warned at the beginning that you would need persistence!

Here is the completed picture of the Volvo:

I hope the effort has been worthwhile. If you have any problems with Draw, and you feel I could help, please contact me by telephone (0161 652 0930), email or snail-mail. My address is as follows:

Interactive Draw Tutorial Tom Beeley's Interactive Draw Tutorial is a comprehensive course which allows anyone to learn how to use Draw effectively. For more information, click the image to the left.