Some objects are simple, so simple you can create them from scratch by just studying it and taking measurements. Take a look around, you’ll see plenty of this kind of objects. But also many difficult objects, with elaborated shapes. Put your ruler back into your schoolbag, it won’t be of use this time.  The main known solution to model a difficult object is blueprints : they aren’t blue anymore like architect drawings 50 years ago, we’re talking of orthogonal views of a picture : front, rear, side, and top views, usually. Using them, you can locate in our 3d space any specific point of the object.

But for some objects, there is just no blueprint. What have we left ? Pictures. It’s easy to have pictures of the object you want to model. You can take them yourself with your digital camera, or you can grab tons of it on the www. Some people can use them to create a model only by eye, but it requires some serious attention because of perspective. Perspective make closer things bigger, so the proportions can’t be trusted without correcting perspective.

Here comes in the approach I wanted to introduce : using a dedicated software to get rid of perspective.

How does it works ?

Consider our 3D space, where the object stands, and a set of cameras around it. Each camera took a picture. Put each picture in front of its camera, on a transparent sheet. Look from the location of the camera, the picture will perfectly match the object behind it (if you don’t consider the optical distortions induced by camera defects)

So you’re able to compute a 3D model from a set of pictures. Of course it’s a simplified 3D model : e.g. I only used 171 specific points. But it will be just a basis to draw a better spline cage.

Using insight3d

insight3d is a Free Software, available for free at http://insight3d.sourceforge.net for both Windows and Linux. Once installed and executed, it shows up with its unusual interface :

We’ll start straight away. I assume you already gathered the reference pictures of your object. Mine is a car, a concept car only shown on a couple of Motor Shows and for which no information no blueprint is available. So I’ll add my first picture, using the menu File > Add Image. Tip : you can zoom the image using scrollwheel and pan it using middle button.

Use the “Points Creator” button on the left to activate the tool allowing you to place the reference points on our first picture.They’re represented by little crosses :

You can see on the picture that a little popup with the zoomed-in portion of the image under mouse cursor to help you place the points more precisely. It will conveniently auto-disappear if you zoom in enough. Nice attention from the developer.

Add another picture now, it will appear but the reference points doesn’t show up. You have to place them. But insight3d must be able to do the connection with the ones you placed in first picture. To do so, use the PageUp and PageDown keys to go through the list of existing points. They will appear on the left of the mouse cursor, conveniently allowing you to see all the occurences of a given point in all the pictures you already add. The picture below shows 2 things on the popup : the zoom and the sample of the previous picture showing this point.

When moving the mouse over a cross, the popup shows again to display the same point in all the previous picture.For example, the previous picture shows two thumbnails in popup : the location in the previous picture of the reference point we’re about to place in this picture, and the zoomed portion of this picture under mouse cursor. When you’ll have placed this point, the popup window will auto jump to the next reference point. Nice attention from the developer, again.

It’s now time to place more and more points, to get enough data so insight3d can compute the camera locations and triangulate the points. You can try that whenever you want, by using the menu item “Calibration” > “Automatic calibration”, and then the item “Modelling” > “Triangulate user vertices”. Once these two steps performed, insight3d should display green dots near the crosses, to indicate where it computed the position of our references points from the reconstructed model.

You may have noticed that the reference point on the right (near the popup) has no green dot. That means, the current amount of data (number of pictures and number of points) wasn’t enough for insight3d to compute the position of this reference point in 3D space. It’s easy to fix that, simply by adding more and more points, on more and more pictures. As an example, my final set is using 171 points on 15 pictures for the real project about this concept car.

Also, the green dots may be slightly off the cross. This means insight3d discovered an incoherent location of the reference point on this picture : the green dot shows the place where the reference point should be, according to insight3d. It may be right or wrong, because the computation it performed depends on the precision of your work (that means, how precisely you located points on all the pictures) Don’t hesitate to zoom in to locate points really carefully, it will help insight3d to reconstruct a more accurate model. Another good thing is to use many pictures. Theoretically, 2 pictures are enough to perfectly locate a point in 3D space, because there will be only one intersection of the 2 lines. But as placing a point on a picture perfectly is not possible, many pictures leads you to a beam of lines, to compute an average position, much more reliable because the errors are minimized.

Exporting the work to Blender

First, you export the model from insight3d. I used the VRML format, by using the menu item “File” > “Export VRML”. Then, into Blender, use the menu “File” > “Import” > “X3D & VRML 97″ (the last entry in Blender 2.49b) Do not use the “File” > “Import” > “VRML 1.0″, it won’t work. When done, a cloud of points (vertices) shows up in Blender :

It’s too bad but insight3d didn’t export the two-points polygons, so you’ll have to recreate the edges. Enter Edit mode (Tab key) and create edges by selecting two vertices and press F key. When done, you’ll have the following (this picture shows a work-in-progress version of my project, so there is less than 171 points)

Because insight3d doesn’t know about the ground and the natural orientation of our model, it appears randomly oriented. So we have to align it properly. For that purpose, I use the yellow edge in the following picture :

This edge goes from the center of a wheel to the other one. So it defines horizontal and rear-end orientation. I use this property to align the model. Also, pay attention to the middle vertices (shown in the white line below), they should be aligned as much as possible.

Here’s the full model (171 dots) once properly orientated, untouched from insight3d except for a mirror modifier : you can clearly see the proportions looks right, and the shapes are accurate. It’s only up to you to use more and more points, to extract more and more details from the reference pictures and to bring them to your 3D model. For example, here’s the current look of my project (as of writing) : I just used some more points, and added details into Blender :

Some extra features within insight3d

Automatic reference points : insight3d features the ability to discover reference points automatically, based upon a picture pattern recognition. This better applies with close pictures, without few changes from one picture to the others. The tutorial available on the insight3d website presents this feature for buildings, and there it works well. For my example, using various points of views and several backgrounds behind the model (different motor shows), it didn’t work. So I had to create all my reference points by hand. Make sure to take a look at the tutorial on insight3d website if you want to try it.

Polygons : insight3d allows you to create polygons, to be exported to Blender. I don’t use the feature that much, except to create lines (2 vertices polygons) to follow the body lines of the car I was working on. The key tool for that purpose is the “Polygon creator” button on the left side. When activated, you can select a number of reference points, and a polygon is shown using the points you selected. You can confirm this polygon and move on creating the next one by pressing the Enter key. At any time, you can circle backwards through all the created polygons using the BackSpace key, and use the menu item “Edit” > “Erase current polygon” to delete the polygon shown in pink.

Cameras : insight3d also supports cameras export, but unfortunately I didn’t achieve a useful result. The exported data for cameras (location, rotation) doesn’t match the imported model. insight3d does support exporting to other file formats, for example the .rzi files used by Image Modeler, a similar program by AutoDesk. Opening the .rzi file into ImageModeler (export by insight3d) didn’t work either. I guess there are different coordinate systems for the different exports available from insight3d, but I didn’t try to read the source code to understand the relationships between these coordinate systems.

Save often : There are some minor bugs with the current version of insight3d, 0.3.2. Even if it’s a small version number, it’s already quite stable. However don’t forget to save often your project.

One final though

One critic about insight3d, about feedback & support.

During my project, I encountered several bugs. An annoying one is : the project file doesn’t support the use of spaces in a folder names (at least in the Windows version I used) I tried to reach the developer about that, but I get no reply from him. He looks like he doesn’t reply to incoming emails about his software and a comment on BlenderNation announcement of insight3d confirmed my fear. Let’s hope this article can cause him to change his mind !

Picture credits

The first picture of Lamborghini Sesto Elemento (shown twice in this article) was found in Wikipedia, author is Alainrx8. The two others pictures of Lamborghini Sesto Elemento were shot by Thomas Durand, known in the modeling scene as AMV12. Congratulations to both of them for these nice pictures.

I based this work on my latest project, a coupe-convertible Citroën C5. If you’re allergic to this brand, or to cars in general, don’t worry : this material applies to any manufactured project : no matter it’s big or small, no matter it’s cheap or high-end.

The tutorial is a on-going series of posts. It starts from the very beginning of modeling and covers every aspect : hard surface modeling with a focus on high-end quality and accuracy, best meshing practices to create a nice polyflow, tips to soluce most common issues. More than just the body, it will deals with all other parts creation : tires, rims, wheel details, windows, grilles, chrome and rubber trim, with also a fully detailed interior.

It already exists in two different languages, english and french. It’s also an interactive process : you can follow the progress of the tutorial as I write it, and you can comment, critic or ask for any complement you want. Please head to the following forums :

• English version is at SMCars.net : http://www.smcars.net/forums/tutorials/34591-modeling-car-high-end-detailed-tutorial.html
• French version is at BlenderClan : http://blenderclan.tuxfamily.org/html/modules/newbb/viewtopic.php?topic_id=27941&forum=5

Both forums requires sign-up to post comments or questions, but it’s free and worth the time it will take you. If you want to contribute with translations in other languages, let me know in a comment.

Stay tuned for more, and meet you there for your feedback !

Grass is only a small part of the above picture, but having it realistic add a lot of credibility to the whole picture. I started to work on grass for my current project, a C5 DTM Coupé concept for the SMCars.net contest “Real World Racer”. I wanted to add a good scene, something I didn’t do for the previous project, the Marcos 1800 GT. And what more intuitive than a race track for a race car ?

Modeling the grass

Blender has a very nice feature, particles system. There is even a particles system dedicated to hair, fur or grass. It’s really easy to use, and especially easy to tweak to make the grass high, low, dense, sparse, aligned or disturbed. Please follow steps 1 to 12 in the first link above : http://www.yafaray.org/documentation/tutorials/particles1. I just used different settings to match my need :

• I use about 3000 particles per square meter. That is, 3000 grass pieces. When you create your emitter, just compute its area and set the particles count to follow this rule of thumb.
• I used the following physics setting : for initial velocity, 0.008 as normal and 0.005 as random, and for global effects, AccZ of -0.001.

Once we converted the particles system to mesh then to curves then back to a mesh but with thickness this time, I copy the original particles emitter object to a hidden layer, making future changes easy. I said “I copy” because I need to keep the emitter surface as a ground below the grass. For this object, just turn off particles, a simple surface will do the job.

You now have 2 mesh objects : a dense one, for the grass pieces, and a light one, the ground below the grass. We now need to quickly create 2 shaders to see the result : just a green and a brown one will be enough for now :

Rendering it with a simple lighting (DirectLighting with SunSky background, no sun) will give you the following :

It’s a bit too simple as of now, but the modeling is done.

Rendering a realistic grass

Turn the previous simplistic render into a realistic one is easy. We just need to add a grass texture to create color variation on the grass.

I used the one provided in the second tutorial I linked at the top of this article : http://blenderartists.org/forum/showthread.php?t=68269. Here’s that texture :

It’s a basic texture set : just add an Image texture to the previous Green shader, select the image file and voilà ! No other setting need to be tweaked.

It’s time to render again :

Except for a gap between ground and grass, we’re done. For the real use I showed in first picture of this article, the work is exactly the same. I just took care to measure the surface of my emitter mesh to achieve a proper grass density.

You can now play with particles settings, and texture, to get a different looking grass. Show your own below in comments !

As I stated it as an objective for the project, I wanted to create all my shaders on my own. Here’re the current settings I’m using and how they look like.

Of course they can’t be considered as definitive shaders. But they can be of interest for your own work and experiments, so here they are.

Clay

Clay may look useless, as Yaf(a)Ray offers an option to render a scene in clay, no matter what shaders have been defined (or not)

But how can you render a whole model in clay except the windows ? You can’t with the builtin feature of Yaf(a)Ray. Here comes the need for a clay shader. The main advantage of the settings below is that they are the very same settings used internally by Yaf(a)Ray. So a whole model rendered clay by Yaf(a)Ray and a model using only this shader will look the same.

Car paint, glass, rim alloy : most noticed shaders

The car paint lacks some metallic flakes within it, I will work on it later and post updates here : don’t miss them !

The glass shader is the default setting from Yaf(a)Ray. It just does the job, provided your windows have some thickness (otherwise Yaf(a)Ray can’t compute refraction properly) and you set enough rebounds in the Depth parameter. Especially, you need to increase this setting if you have a window laying behind another one, like I do have in my render.

The rim alloy is a glossy, dark one :

Plastics

Below are a mat plastic and a shiny one. Both are black, but notice I didn’t use #000000 as color : in real world, a black object is never completely black as #000000 is, because it actually does reflect a bit of light.

Rubber

Below are a mat rubber and an attempt for a waxed rubber. Mat rubber perfectly does the job for joints around windows, for example.

The waxed rubber was intended to look like a brand new shiny tire : waxed. This attempt is a failure so far, so I will have to fix this as soon as possible. Stay tuned for updates here.

Chrome

Chrome has never been a complicated shaders : setting a fully reflective shader will work most of time. I didn’t need more complicated solution so far, so here’s a simple shader.

That is, when you want to model anything with precision or accuracy to an existing object. Why bother with this ? Because I’ve learned to value the acuraccy of a car model as well as the simple beauty of a render. It’s a matter of taste, and I just think it’s more grateful to achieve an accurate model than to rush to produce something-looking-a-bit-like-but-not-really-the-same.

By the way, happy new year !

If you don’t want to read much

For precision modeling, the shortest advice is : define yourself the scale you’ll be using for your model. By writing this, I mean that there is no feature in Blender such as “define which size is a meter or a foot or a parsec or whatever length unit you can think of”. There is only Blender units.

So the first thing to do is, define what a Blender unit represents. For example, I’ve always used “1 Blender unit stands for 1 meter”. So any precision like, e.g., a 5 mm gap between 2 body parts on a car is reachable : it’s just, for that example, a matter of 0.005 Blender unit.

Still there ? Want to read (much) more ?

For a longer advice, one top level reading is the book from Robert Burke. He was published in BlenderArt some issues ago, and the book is a longer version of the published tutorial. There was an article on Blendernation about it some days ago : Precision Modelling PDF Guide at BlenderNation. The guide is available on his site : rab3D.

This is a 150 pages book. It’s really worth reading !

Bonus : another way to use blueprints

There is another scale or resolution to use with Blender.Maybe you’ve also heard of the “native resolution of Blender”.

As far as I know, it’s used only for background texture. It define which size will have a picture (of a given height and width in pixels) within the Blender viewport.

The so-called native resolution of Blender is 512 pixels for 2 Blender units. The screenshot below shows a 512×256 blank image loaded in Blender, with a zoom factor of 1.0 :

To show up such a picture in background, use the menu entry “View > Background image” with any 3D view. I’ve added a 2.0 Blender units edge to explicit the dimension, below the picture.

If you want to use a given scale like I wrote above, you then have to compute the zoom factor to use : if this picture was a print of a car 4.73 meters long, you just put 4.73/2 = 2.365 a zoom factor.

The last control to use within that panel is the offset : you can move the picture to match any arbitrary reference. Use the “Xoffset” and “Yoffset” controls to specify how much the picture should be slided respectively horizontally and vertically. The figures you specify there are in Blender units, so for the scale I use, in meters.

This is an alternate way to setup blueprints to the tutorial I’ve wrote some times ago : Blueprint setup in Blender.

I still keep working the way I described in that tutorial, because it has two advantages I think :

• No need to use a viewport subdivided in four 3D views to show 4 different pictures, like the front / rear / front / top views of an usual blueprint.
• It’s easier to show / hide blueprints : instead of clicking the “Use” button you can see in the above screenshot, I dedicate a layer for blueprints and with keyboard shortcuts like Shift+5KEY (if the UV-mapped blueprint box lies in the 5th layer)

Of course, my previous way has a drawback : you have to show the parts as wire. Otherwise they’re will be hidden on the UV-mapped blueprint box.

• First page is about light and the mechanics behind it,
• Second page is about the effects on a photo of the light location,
• Third page is showing the different lighting possible at different hours or with differents weather.

I’ll show you how to use this material in Blender to produce simple but realistic lighting. As usual, I will produce some renders with YafRay.

Introduction : setting up the simplest scene you can imagine

Differents pictures in the Itchy article (like this one or this other one) show a common scene : a white ball, a white ground plane, and a simple sky surrouding the ball and the plane :

To achieve it in Blender, it’s really simple :

1/ Start Blender and erase every object of the default scene (AKEY twice to select all, XKEY to erase)
2/ Place 3D cursor at origin (Shift+CKEY) and in TopView (NUMPAD7), add a plane (SPACE >> Add >> Mesh >> Plane) Scale it up (SKEY and enter 4 on your keyboard, then ENTER) Exit Edit mode (TABKEY)
3/ In side view (NUMPAD1), add a sphere (SPACE >> Add >> Mesh >> IcoSphere, Subdiv at 3) and with all vertices selected in Edit mode, move the sphere upward (GKEY, ZKEY then enter 1 on your keyboard, then ENTER) Exit Edit mode (TABKEY)
4/ Add a Camera (SPACE >> Add >> Camera) and adjust your point of view with middle mouse button to get an interesting perspective. Once you find it, adjust the Camera to respect this point of view (Shift NUMPAD0) Check the point of view with NUMPAD0 to activate the camera.
5/ If needed you can do some adjustements, by moving the camera or the sphere on the ground plane.

Lighting the scene

I will describe two light setups from the article by Itchy : midday and sunset. There is common settings for both lightings and a specific part for each one. Common to both lighting :

• Define a simple sky : in the Shading panel (F5), under World buttons, select a light blue as horizon colour (#B1D6FF) Zenith colour is useless as the sky is uniform. This colour should be replaced by another one if needed, but it works well for both midday and sunset.

Specific to midday :

• Add a Sun light, with colour set to white (#FFFFFF) The location of the light doesn’t really matter, but its direction does : rotate it to have your scene lighted from the top. Why ? Because the sun is high in the sky at midday !

Specific to sunset :

• Add a Sun light, with colour set to a light red (#FF4F00) As above, the location of the light doesn’t matter, set only its direction to have the scene lighted from nearly the horizon, like where the sun lies at sunset.

Rendering the scene with YafRay

As this is only a teaser, there is more to come ! I will complete it as soon as possible. Until I publish it, you can use my previous tutorial about rendering with YafRay : Realistic clay render with YafRay and Blender.

Thanks for waiting

Not so many words here, please pay attention to the pictures. All information is in them.

Step 0, I setup my blueprint :

Step 1, I model major bodylines, to have a sketch of the car :

Step 2, I can close polygons to have a real mesh. This step needs tweaking of bodylines to get a clean polyflow :

Step 3, now polygons are set up. I need to get smooth transitions when needed. Or hard edges on some places. So I subdivide my mesh with Blender subsurf modifier. That way all defects will be visible with default in-scene lighting.

Step 4, I move some vertices rows to create empty space between body parts :

Step 5, it’s time to give some thickness to the body. I also add extra vertices rows to give hardness to edges needing some

Step 6, time to model details (work in progress as of writing) :

Time to test a render. Here’s a clay render, using relatively simple Yafray settings :

Foreword

When I was a newcomer in CG cars world, I’v oftenly seen a word I didn’t understand (as a non-native English reader) : clay, as in “please show us a clay render”.

Asking my favorite dictonnary, I understood that clay render refers to the clay designers use to produce physical mock-up of a concept car. It’s easy for any one to draw some curves on a paper sheet or in 3D/CAD software, but to fully define the shape it’s easier for them to work with a physical medium (e.g : curves intersections or transitionnal shapes). That is, the clay.

For us, amateurs CG artist (or confirmed or even professional), a clay render is of interest to show the defects of our 3D model. Why ? Because clay shows curvature variations well, and unsmooth variations look unnatural. Here’s an example :

Overview

I already told you it will be short :

• Step 1 : create a dedicated material to represent clay
• Step 2 : scene setup

That’s all

Step 1 : clay material

Create a new material on a dump part.

The following characteristics are the exact and complete settings I use :

• Diffuse colour : #D6C796
• Specular colour : #CDBE90
• Mirror colour : #FFFFFF, useless as there is no reflection on clay
• Diffuse shader : Lambert, Ref 0.69
• Specular shader : CookTorr, Spec 1.135 and Hard 8
• Mirror Transp tab : choose preset “No Reflect/Transmit”

I advise you to setup your material this way, have a render with it then start only tuning it to adapt it at convenience.

Step 2 : scene setup

For my common clay renders, I do the following :

• Duplicate all the parts constituting your model : select them using RMB for the first one then Shift+RMB for the other ones. Then Shift+DKEY, then ESCKEY not to move them.
• Move them to another layer : MKEY to show the list of layers, select one empty layer and confirm.
• Change to this layer.
• Join the several parts into a single one : Ctrl+JKEY. It’s just more convenient to change material for one part than for N.
• Change the material of this part : select the previously created “Clay”.

Now come the core scene setup (above steps were just a training) :

• Add a white plane (or any color/material you like) under your clay model.
• Go to Shading panel (F5KEY), “World” buttons. Change settings for a full white sky. I expect the sky not to create any artefact on the model at render time : so I use a constant lighting.
• Go to Scene panel (F10KEY), select Yafray as rendering engine.
• I use full x16 antialiasing (oversampling as Blender call it) : click on “OSA” and “16″ buttons to activate them.
• In “Yafray GI” tab, select “Full” as Method and “Best” as Quality. Change also EmitPwr to 1.3 to have a brighter scene.

Launch render, and stay tuned with a full bottle of coffee. On my hardware, Full/Best/OSA16 setting is so slow that I can’t stay in front of display to see render progressing.

One hour later (or two, or ten, or … depending on model complexity) here’s what I got :

Please don’t be afraid by the length, you just have to sit and follow this step-by-step : nothing to guess or read between lines.

Before starting Blender

Get the blueprint See my ressources page to have some link to start with.

Then search for car dimensions : length, height, width (take care of which width it’s : including sidemirrors or not, for example).

I use metric system but it doesn’t matter to use another : just stay coherent from one car to another, in case you want to mix scenes : whole cars, rims, environment, etc.) A Blender unit will represent a meter in my scenes.

Scene setup

Start blender with default scene : a cube, a lamp, a camera.

Remove lamp and camera. Select the cube and enter edit mode. By default cube edges have length of 2.0 units. You can verify it by using “Edge Length” button in Editing panel (F9)

This value of 2.0 means (for the use I make of Blender units) 2.0 meters. Size the cube by a 0.5 factor to have edges of 1.0 (it will be 1 meter) :

* AKEY to select all vertices,
* SKEY to enter resize function,
* Type 0.5 then ENTER to confirm

Move the cube upward (Z axis) by 0.5 :

* With all vertices selected (AKEY if needed)
* GKEY to enter grab function.
* Type ZKEY to constraint move along the Z axis.
* Type 0.5 then ENTER to confirm.

You have now a cube whom bottom is at Z=0 :

I take the following sample values for car dimensions :

* Length : 4.70m, along X axis in my scene setups (oriented back to front)
* Width: 1.80m, along Y axis in my scene setups (oriented left to right, from inside the car)
* Height: 1.30m, along Z axis in my scene setups (oriented bottom to top)

Now resize the cube according to car dimensions :

* Choose 3D Cursor as rotation/scaling pivot in the menu at bottom of 3D view.
* Check the 3D cursor is at origin, enforce it if needed using SHIFT+CKEY.
* Select all vertices with AKEY.
* SKEY, XKEY, type 4.70 then ENTER.
* SKEY, YKEY, type 1.80 then ENTER.
* SKEY, ZKEY, type 1.30 then ENTER.

You get the following cube :

In the previous picture, only two vertices are selected : the upper-most on the left side (from inside the car). Select these two vertices on your own cube, using RMB for first one and Shift+RMB for the second one. Then remove the edge by pressing XKEY, choosing “Edges” in the popup menu. You get the following :

Why doing this : to keep only 4 faces on it : the four view of a common blueprint : top, side, front and rear. One more step : invert the normals : press “Flip Normals” button in Editing panel (F9). You can check the normals are directed toward the inside of the cube by clicking “Draw Normals” in the same panel :

Why having in-normals ? This way you can have a glimpse of top print by putting it in the bottom face of the cube and looking to it from top view (NUMPAD 7). Just now have to put the blueprint on it

Blueprint time !

Before actually putting blueprint, we have to split the current 3D view in 2 parts :

* The 3D view to view the cube, select faces and check the blueprint.
* The UV/Image Editor, to load blueprint image and map faces on it.

To do it, move mouse cursor just between menu bar (at top of window) and 3D view (that’s it, on the border line). The cursor changes to a vertical double-arrow. Press MMB and select “Split Area” in the popup menu : click in the 3D view to split it. Then you get two 3D views.

In the right one, change window type to “UV/Image Editor”. You get the following screen :

You’re ready !

In 3D view :

* Escape from edit mode (TAB)
* Enter “UV Face Select” mode using “Mode” selector at the bottom of 3D window.
* Select all faces with AKEY.

In UV/Image Editor :

* In menu “Image”, choose command “Open…”
* Select your file containing the blueprint image : I advise you to use PNG format, more suitable than JPG and lesser in size than BMP. I remind you that GIF is not supported.

You get the following screen (image credits go to the one owning the rights) :

I wrote to select all view just to make sure image is loaded for all 4 views. But now you have to work one view at a time :

* In 3D view, select only one face using RMB.
* In UV/Image Editor, you get 4 vertices on each corner of the image.
* Move corners 2 by 2 (a side at a time) to line up to the blueprint using GKEY to enter grab function.
* I advise you to move top and bottom sides only in vertical displacements, to keep them horizontal (horizontal displacements for left and right sides) You can use XKEY and YKEY while in grab function( XKEY to allow only horizontal displacements, YKEY for vertical ones)

You get the following :

Now in 3D view press ALT+ZKEY to select “Textured” as “Draw Type” (available also at bottom of 3D view)

You can see 3 things :

* First, blueprint appears on each side. Good point.
* Then, side view is lined-up. Another good point.
* Next, obviously, something is wrong : side view needs rotation.

Go back in UV/Image Editor, select all corners using AKEY and rotate the picture 90° (or 270°, as needed) using RKEY and typing 90 (or 270). Redo the line-up work side by side, and this time you’re done.

Do it 3 times more for the other views :

You may have noticed I put front view in rear face, and rear view in front face. It’s not a trick, the same is for the left view (being in right face) and top view (being in bottom face). Using inversed normals, the face supporting the front view points toward the front (and so on for other views) : this is correct lineup.

Congratulations, blueprint setup completed !

What you need first

A sketch of the tire, like this one (PIRELLI P6000) :

The dimensions of the tire : let’s use a 205x60r16.
Principia

From the dimensions of the tire we guess that :

* The width of the sketch image is 205mm
* The external diameter of the tire is 16inch + 2 * 60mm = 16*25.41+2*60 = 526.56mm

From the image size (in pixels : 500*190), we calculate the height of the image (a part of the tire thread) is 205*190/500 = 77.9 mm

As the diameter of the tire is 526.65mm, its perimeter is 3.14159265 * 526.65 = 1654.52.

So on our tire thread, we can put N times the sketch image with N = 1654.52/77.9 = 21.239. As the image tiles, we need an integer : let’s say our sketch fits 21 times around the tire.

So, we’ll create a 21-edges circle, extrude it to have one face fitting well over the sketch. Next, we’ll model one element (1/21 of the full tire). Multiplying it 21 times, merge, and voila !

Scene setup

Open Blender. Erase all elements of default scene.

In side view (NUMPAD 1), create a circle of 21 vertices. Rotate it to have the bottom edge perfectly horizontal (tip : align top, opposite vertice with the Z axis)

As Blender default circle radius is 1.414 (square root of 2), size it by 0.707 (1/1.414) to have radius to 1.0. Then size it by 0.526/2 = 0.263 (tire radius in meters) and move all vertices up by 0.263 (the radius). It’s OK that the bottom edge is not on Z=0 : we’ll see later why.

Duplicate this bottom edge, separate the duplicated vertices to have another object. Extrude it along Y-axis by 0.205 (the width of our tire). You got a plane and a circle like these :

You can check your work is OK by displaying edges length : you should have 0.205*0.078 for the plane.

One more step and you’re done : duplicate the plane, change one to display only as Wire (Drawtype in Object panel, F7) and select the other one. Enter “UV Face Select” mode, go to UV/Image Editor and load the sketch image.

Return to 3D view and “Object” mode, activate Textured draw type (Alt+ZKEY), you get the following :

The sketch is displayed correctly, without any distortion : the few maths before starting Blender was not useless

First step of modeling

Select the other plane (the transparent one, without U/V texture). We’ll work on it to model a subpart of the tire thread.

First use symmetry to save you some work : the sketch we have can be split along both X (radial cut) and Y axis (axial cut). So you can subdivide once the plane (in both length and width).

But before you do, PLEASE READ CAREFULLY BELOW !

When splitting your edge along Y axis, no problem. But when splitting along X axis, remember you’re not working on a plane but a section of a cylinder.

That’s why the bottom edge of the circle is not at Z=0. Let’s experiment to get a clue. If you already subdivided the plane, please undo it.

Then cut the face (CTRL+RKEY) at percentage 1.00. Don’t select/deselect anything to keep new vertices selected.

Then, rotate carefully these vertices around Y-axis (RKEY then YKEY) to get them at X=0 (as seen from top or side view) And in side view (NUMPAD1) you can now check that these vertices are almost at Z=0.

Remember this move : when cutting along X axis, do not move edge vertices along X axis, but rotate them around Y axis, to move them around a perfect circle.

Just a little note : you have to move the plane textured with sketch down to get the added vertices above it (so they’re still visible)

Now you can continue with modeling : remove 3/4 of the plane as said above, and cut plane according to each detail visible on thread : you should get something like that :

As you can see, cuts in the plane are mapped on thread details, but for round details, it’s not that yet.

To solve it, just rotate them around Y axis :

This time round details are OK.

As you can see in side view, the tire element is not plane but warped around a circle :

This is why it’s so important to rotate vertices around Y axis instead of translating them along X axis.

Now, we will cut the edges in dark areas, to materialize the hollows of the thread : you should obtain this :

It’s important to keep the edges circling the dark areas ! We will see why later.

Now it’s time to optimize a bit our mesh : we have to remove all unneeded vertices and edges in white zones and on borders. Doing this will allow us to save a lot of polys on the complete tire (remember, we will duplicate this part 2*2*21 = 84 times !!!)

Vertices count goes from 144 to 78, faces count goes from 53 to 22. Good point !

Some thickness

Time to model the hollows !

From the previous step, select all vertices.

Extrude them (EKEY) but without moving them (ESC immediately)

We have to move them to the tire center, but a simple scaling (SKEY) will not do the job : it will act on Y axis, and we don’t want that. Just try by yourself to see why, then undo

So we have to scale 2 times : first on Z, second on X. Make sure before scaling the 3D cursor is at circle center.

When scaling, I advise you to enter a value with numpad : this way you can enter the same value twice, for Z then for X. A value of 0.99 is a good starting point.

Now make needed faces between extruded vertices, to model the bottom of tire thread. The next image is a work in progress to show you the faces needed :

You get the following once done (seen from under the tire)

Next step is simple : remove faces that interrupt hollows in thread. Look close to this screenshot to find differences with previous one :

Now it’s time to model the side of the tire (i.e. the 60 in 205x60R16)

Start with the external, upper edge of the element, and extrude it without moving it. Scale along X and Z axis (but not Y, as previously).

Work on it to get a rounded side. I advise you to spend some time working on this part, it’s really important for realistic tire :

Save some polys on the side :

You’re almost done !

Complete tire

SpinDup the element you patiently modeled (1 turn, 360� of course, 42 steps : because we need 21 elements and the mesh we have is only a half).

Once SpinDup done, you may observe your border vertices are not perfectly one duplicated ones : select all vertices, and remove duplicates (set threshold at 0.001)

You have now to mirror the tire : select row of vertices at the middle of the tire, and move 3D cursor to selection (to have it at tire center, in the middle plane of it) Duplicate the half tire, don’t move it, but rotate it 180� in top view (around 3D cursor). Rotate around Y axis to align middle vertices to the ones of the other half tire.

Merge : you’re done !

I advise you to use this mesh with AutoSmooth, to have solid thread details and smooth side.

Here’s some Yafray renders with a rim (black tire material courtesy of Sonix, found in its excellent Car Material Library)