55 replies to this topic

[Renzsu]

Hi there and welcome to my second tutorial. Perhaps weird to do so, but I would like to open with a word of advice. My mind can be quite chaotic at times, during this tutorial it certainly was. I made a number of silly mistakes and I'll show them to you in the course of the tutorial. So please read through the whole tutorial first.. you'll notice some things that I would change from the start if I were to make this image over again.
If you don't quite understand what happened in a certain step of the tutorial, just read on, there's a chance that I will explain in a later step to prevent having too much text with some images.

If you're familiar with the field of concept design, you'll probably have heard of a guy named Scott Robertson (website drawthrough.com). He has produced an excellent set of tutorial dvd's for The Gnomon Workshop, one of which shows the process of rendering a futuristic bicycle.
My tutorial uses the same techniques, though perhaps my approach will differ here and there. Anyways, Scott gave me his permission to publish this tutorial, for which I'm grateful.

Right, lets get this thing on the road.
In the Photoshop screenshot below you can see I have started out with a background and an enlarged rough sketch that I prefered to render out. Between the really messy sketchlines you'll probably see some cleaner lines that I imported from Rhino. They were traced from a Yamaha R1 motorcycle sideview. I used these to make sure my proportions wouldn't be too far off.
Put the sketch that you want to render out on a seperate layer and set the layer to Multiply and turn down the layer opacity so that it is just visible enough to be usable for tracing.

The background you see is very typical for studio photographs of cars and other vehicles. In the renders I made below you can see the effect I tried to accomplish.
Making this background is really easy, you could do the whole thing with a simple gradient, I simply used some big soft airbrushes from the default Photoshop palette. Try to avoid using the opacity of 100%, if you turn it down you can achieve much softer effects if you make a couple of passes with the brush (think of it as using a tissue with chalk powder).

 tut01.jpg   85.82K   1210 downloads

[Renzsu]

I put down a simple drop shadow here, it will make a big difference in a few more steps.. Simply use a soft and small airbrush to create the shadows.
Now I will probably modify the shadow later on when the bike render is done, but for now it's good to just have an indication there of an object that is shown in this studio setup. You don't want to render a bike that seems to be hovering over the ground. A shadow gives an immediate effect of mass.

Notice the basic layer setup:

sketch guide: the initial sketch + rhino proportions drawing; layer set to multiply (so it will display over all the objects below. I set the layer to an opacity of about 40%, just enough to keep it useful for throwing down some Photoshop Paths later on.

Layer 2: still empty, but imagine in this place all the layers needed to create the actual bike rendering later on.

ground castshadow: I think this one is pretty obvious. Don't merge it with the background though, if you want to move your bike later on you don't have to create a new background and shadow if you keep things seperated.

background: the background shot that we created earlier on.

 tut02.jpg   82.39K   651 downloads

[Renzsu]

Ok, important step here, you can chose to do it later, but I prefer to lay down some guides as soon as possible.
Activate the rulers with Ctrl+R, click on the left ruler and drag till you see the guide on your image. You'll need two vertical guides, once for each wheel. Locate them to where you want to have the center of each wheel (axle position).
Now from the top ruler click/drag three guides on your image. Position one of them where your wheels will touch the ground and the other two on your wheel axles. I dropped my rear axle slightly higher than the front one, I want to have a bigger rear than front wheel.

 tut03.jpg   110.4K   525 downloads

[Renzsu]

Time to start the tedious stuff Paths!!

Lets start of with the wheels. Click the Ellipse Tool  ellipse_tool.jpg   21.53K   185 downloads (U) and before you draw some ellipses, make sure that in the Options bar below the Taskbar this icon in pressed  paths.jpg   21.89K   131 downloads. This will make sure that the ellipses you're about to make will be made as paths and not shapes.
Draw an ellipse with the Shift key pressed. This will force the ellipse to become a circle.

Now your circle is probably too small or too big and not positioned where you want it. We'll solve this First you have to make sure you have snap turned on ( Shift+Ctrl+; ).
Press the Path Selection Tool  path_selection_tool.jpg   21.49K   128 downloads, select the circle you just made and drag it onto the intersection of your guides. With some dragging left/right and up/down you'll soon enough see your new circular path snapped to the guides.
With the Path Selection Tool, we'll now scale your path so that it drops right onto the guide you made for the floor. Chose Edit > Transform Path > Scale. With the handles around your path you now can scale your path. Make sure you keep Shift pressed so that you won't stretch it back to an ellipse
Again, it might take some effort for the handles of the transform box to snap to your guide, but with some persistance it should work just fine. Press Enter to approve your scale and that's one circle done

Now we need a couple of these circles.. I created one for the outer edge of each tire as well as inner edge where the rim will start. A fifth circle was made for the shape where the rear wheel suspension will hinge.

 tut04.jpg   123.71K   495 downloads

[Renzsu]

First thing you'll probably notice here is I flipped the image horizontally. Why? Well I prefer to sketch motorcycles with their front wheel to the left. The reference photo I used showed the other side of the motorcycle, with the front wheel to the right. So my sketch had parts on one side that would be on the other side on a real motorcycle (at least, on Yamaha motorcycles in that range). I found this out around this step in the process... so I simply flipped my image horizontally (notice, if you flip your layers individually, their orientation in respect to eachother might be lost, because the layers are flipped around their own pivot points. You won't have this problem when you flip your whole image in one go.. which would be faster anyways, but it's good to know ).

Now it is time to make the rest of the paths for our rendering. Paths are vector shapes that are stored inside your drawing as invisible objects, meaning, when you save your image as a .jpg or some other format than .psd, it will not show those paths in your image.
Paths can be used for all kinds of things, but in our image we will use them to create very smooth linework and selections. You can create as many paths as you want and you can always select or deselect them and even modify them.

We will create paths for pretty much all our coloured areas. You can create a path using the  pen_tool.jpg   21.31K   77 downloads Pen Tool (P). Just make sure you have this  paths.jpg   21.89K   85 downloads Paths button selected in your tool bar or else you will be drawing shapes instead of paths.
Draw your paths around the area that you want to colour. Maybe you are wondering 'how do I create two exactly the same bits of linework on the borders of two areas? Do I need to neatly trace the whole border of each coloured area?'. Well, don't worry because you can most likely overlap the paths in those areas, as long as we pay attention to the layer order. This means you can use the border of the one area and have the neighbouring area just overlap because it will be below it anyways.
This can be quite a puzzle, so be carefull where you think you can overlap paths and where it will be harder.

When you create the path, a single mouseclick for each new control point wil create a sharp corner.. if you click and drag you will create a smooth control point.

 tut05.jpg   134.33K   433 downloads

[Renzsu]

The  path_selection_tool.jpg   21.49K   82 downloads Path Selection Tool (A) can be used to select a whole path. With the path selected you can then transform or scale the path, but not with the Path Selection Tool itself (use the Edit menu in the Photoshop Taskbar).

 tut05b.jpg   134.37K   425 downloads

[Renzsu]

Together with the Pen Tool (P), the  direct_selection_tool.jpg   21.55K   75 downloads Direct Selection Tool (A) is the tool that you will use a lot when creating the paths. This tool is used to control each individual control point of each path.
Click on a path with this tool and you will probably see the control points show up as well as 2 handles. With this tool, click on a piece of path between two control points, and the handles of those points controlling that piece of path will show up. If you click on a control point, both handles of this control point will show up.
This tool can be used to modify the control handles of each point, as well as the position of each point. So this is a very powerful tool that you can use to really create the shape that you want.
A good approach to creating paths is to quickly and roughly create a path with the Pen Tool and then after you have created this path, get it to fit properly with this  direct_selection_tool.jpg   21.55K   75 downloads Direct Selection Tool (A).

 tut05c.jpg   132.63K   386 downloads

[Renzsu]

Here you can see that I made the steering arms using a combination of sharp control points (just clicking) and smooth control points (clicking + dragging).

Now you will probably encounter the situation that you have accidentally created a smooth point where you want a sharp corner or vice versa. No problem, use the  convert_point_tool.jpg   19.39K   55 downloads Convert Point Tool (press and hold the Pen Tool button to find it) to change the point after you have finished creating your shape. Using this tool you can click on a point to convert it to a sharp control point and click + drag to convert it back to a smooth control point.

Last thing that I want to point out in this screenshot is the Paths dialog that is shown. Sometime during the creation of all your paths it will be likely that you deselect your 'Work Path'. This will promptly hide all the paths and you will most likely panic Don't worry, you can simply re-select the 'Work Path' and all your paths will be shown again.. I wish Adobe would simply use a hide/unhide button as they do with the Layers... this would be far more consistent and less confusing.

 tut06.jpg   140.6K   418 downloads

[Renzsu]

Well it appears I have created all the paths that I need now (most likely you'll find out later that you need to create even more.. no problem, but tedious, yes ).
Use the  path_selection_tool.jpg   21.49K   62 downloads Path Selection Tool (A) to select a path and make sure you have created a new layer for this bit you're about to colour. Click the right mouse button and chose 'Make Selection...'. Leave the settins as they are in the popup dialog you're shown next and press OK. You will see you now have a selection that you can fill with the colour of your choise.
Repeat this procedure with your other paths and try to keep track of the layer order at the same time. Make sure you create layers with proper names, because you'll likely end up with over 30 layers and you don't want to spend 10 minutes finding the right layer..

In this screenshot you can see that I have 2 black objects overlapping eachother, namely the foot support and the circular shape behind it. I created two seperate layers for this to make it easier later to add highlights.. prevent using objects on the same layer as much as possible if you're really lazy and don't like puzzles (re-ordering layers all the time).

 tut07.jpg   158.31K   400 downloads

[Renzsu]

Before starting the shading of each surface, which means adding the highlights and core shadows, we have a nice opportunity to play with the colours of our bike. Make sure you decide on a colour before we commence with the shading. Of course you can modify the colours when you are finished (because we keep our layers seperate), but it will make life easier if you chose a colour that isn't too hard to shade.
I liked this yellow but then remembered that it is usually a bit of a pain to make shadow areas in yellow look good and not dirty, so I switched to something easier.

 tut08.jpg   135.01K   428 downloads

[Renzsu]

From this point on you will be shading mostly, so you can hide your sketch guide layer that you have on top of your image.

Select the layer of the area that you want to shade (for example the fuel tank) and make sure you have 'Lock transparant pixels' turned on (it's the checkerboard icon next to the 'Lock:' text in your layers dialog). This will allow you to paint all you want without worrying that you paint outside of your coloured area. Because you locked transparant pixels you cannot paint on empty areas, meaning you can paint only in areas where you already have colour.

Paint the highlight and core shadow of each area on the same layer as the object is located. If you mess up, you can simply paint over the area again with the colour it used to be and all is restored. Don't use the eraser, it will simply fill the area that you erase with the background colour that you have set in your Toolbox. Simply use your airbrushes to paint until you are happy with the result. Remember, the bits of the bike that are near the top have a pretty strong highlight on top, the bits of the bike near the floor have a weaker highlight on top, but probably also a highlight from light reflected from the floor. Don't forget to add this effect, it will add a huge amount of realism in your image (you can see this clearly on the plastic bit below the blue fuel tank area).

Again, looking at reference pictures of all kinds of products, bikes and cars in studio setups will teach you a lot on where you can find highlights (don't confuse highlights with reflections though) and shadows. Having good reference around makes life a lot easier.

 tut09.jpg   133.84K   404 downloads

[Renzsu]

Now if you'll excuse me I'm going to be very lazy here
Doing complex shapes like this in a vector drawing program like Illustrator (I used Rhino here because it's great with curve matching and arrays) can really make the experimenting with shapes a lot easier.

You can do these shapes in Photoshop but it would be really time consuming and the end result is only visible after investing quite a bit of time. In Rhino it was just a matter of cutting up a circle in as much parts as I needed, drawing some curves to replace those parts and polar arraying them. I also matched their curvature and joined them to create a single nice flowing curve object.
It would seem this is a lot of work, but when you are a little familiar with Rhino you will know this is actually really easy and a matter of just a few minutes before you can have a set of different versions to play with.

In the end I used Rhino to create the discbrake assembly, the rims of the wheels and the tire profile. You'll see those in later steps of this tutorial.

 tut10.jpg   108.04K   391 downloads

[Renzsu]

Scale down the imported curves (keep Shift pressed to make a nice uniform scale) and snap them to the wheel centers. Make sure you keep track of the layer order, or these will end up on the wrong end of the steering arms

You'll notice that these imported curves have quite thick black lines. This might seem bad, but we can actually turn this into a plus because when we turn on 'lock transparant pixels' we can draw highlights and shadows on these curves.
Before we do this though we need to colour our shapes. Go to the layer where these shapes are on and use the magic wand to select the insides where you want your colour. Create a new layer while keeping your selection and fill that with the colour of your choice. Just make sure you keep each colour on a seperate layer so that you can easily make changes if you're not happy with the result.

 tut11.jpg   150.84K   366 downloads

[Renzsu]

We're now going to try to simulate a brushed steel look that you usually see on brake discs like this. All the painting is done on the layer used for colouring the front disc, so no seperate layers for reflections of shadows are used.. this is a simple object to colour so no need to make things overly complex.

 839_615_301_Brake_Disc_F_Solid.jpg   16.09K   150 downloads

You could use a noise filter here and use a radial motion blur as in reality this shading effect is used by tiny radial scratches, but if I'm being honest I don't think that's a very realistic look. The radially blurred noise would be good for bumpmaps in 3d software, but not for photoshop, because we're rendering the actual highlights of those scratches, not the scratches themselves. They are just too small to show up on shots like we're trying to mimic. So that only leaves the anisotropic effect, which is easily achieved by using a soft airbrush and streaking across the disc a couple of times. Try to achieve a nice and subtle effect.
One nice side effect with glossy surfaces is that they blur reflections. The reflection of the front fork for instance is easily made by using another soft airbrush and going over the area behind the fork. Again, just go for a subtle effect, just don't make the edges of the reflection too sharp. Notice that I call it a reflection, but you can just as well call it a shadow. In reality it would be a mix of both of course.

 tut12.jpg   143.49K   387 downloads

[Renzsu]

For the wheels (rims) we will use exactly the same process. I have imported the curves from Rhino and created a couple of layers for the black areas as well as the blue areas.
For complex assemblies like the rims and disc brakes, it is wise to create not just new layers, but also a new layer group. You can then put all the layers associated with each assembly in their own group. When you select a layer group you can scale/move every layer in that group at the same time. Very convenient!

Now we'll scale the group I created for this front wheel and put it into place using the uniform scale and snap approach I outlined earlier on.

 tut13.jpg   156.86K   676 downloads