Tag: tutorial

Sports Car Article

3D Artist Magazine : Issue 57

The latest issue is on sale now, and you can see an article somewhat misleadingly called back to basics, which provides an overview of designing, modelling, and rendering a vehicle. In this case it’s a futuristic one. I’ll add more renders soon.

[image title=”Sports Car” alt=”Sports Car”]http://www.scorpiocgi.co.uk/wp-content/uploads/2013/07/SportsCar_v005.103a.jpg[/image]
[image title=”Sports Car” alt=”Sports Car”]http://www.scorpiocgi.co.uk/wp-content/uploads/2013/07/SportsCar_v003.104.jpg[/image]
[image title=”Sports Car” alt=”Sports Car”]http://www.scorpiocgi.co.uk/wp-content/uploads/2013/07/SportsCar_v003.160.jpg[/image]
[image title=”Sports Car” alt=”Sports Car”]http://www.scorpiocgi.co.uk/wp-content/uploads/2013/07/image000006_001a.jpg[/image]
[image title=”Sports Car” alt=”Sports Car”]http://www.scorpiocgi.co.uk/wp-content/uploads/2013/07/SportsCar_v004_rgb000006.jpg[/image]
[image title=”Sports Car” alt=”Sports Car”]http://www.scorpiocgi.co.uk/wp-content/uploads/2013/07/SportsCarSupporting2.jpg[/image]

Grading your Renders


The holy grail of pretty well any CGI endeavour is realism. We all want those who view our work to believe on some level that it is real. CGI is notoriously perfect, and great effort is made to try and minimise the perfection that CGI brings. Much can be attained in terms of texturing and taking away the geometric perfection. One area however that sits uncomfortably in the middle is automotive rendering. Now of course you could create an old and battered vehicle, and texture it accordingly. Usually however, cars are rendered to be uncompromisingly beautiful. It is after all where the term ‘Car Porn’ comes from.

This then leaves the post processing or grading to attempt to add realism. This realism is added closer to the viewer. It is not the subject or it’s geometry, but the CAMERA.


Step 1 : Starting Point

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For this tutorial I am using my Lotus Exige model, created with Lightwave 3D, and rendered in this instance with Hypershot HD (now known as Keyshot). It’s a pretty nice render over all, but it does seem to clinical and dead.




Step 2 : Optical Imperfection

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The first step is one of the most important. Camera lenses will generally suffer from Chromatic Aberrations. This is where the light colours separate slightly quite distinctly, as it does when passed through a glass prism. Photoshop includes a filter called Lens Correction, which amongst other things includes sliders to remove colour fringing caused by Chromatic Aberration. We are doing the opposite, and we use the sliders to fake the effect. To some degree it will be trial and error to get the level and look of effect you want.


[note_box]TIP : You can record actions to make the process automated (see the action for download at the end of this tutorial).[/note_box]


Step 3 : Boost your Highlights

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Duplicate the background layer, and apply a Gaussian Blur to it. I find that 5-10px works best, but as with most things, you need to experiment to find your desired look. Typically you need to stay in the mid ground between the finished effect for this layer looking harsh, or to dreamy and ethereal.



Step 4 : Colour Dodge

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Now set the layer mode to Colour Dodge, and the opacity to 35%. This will have the effect of brightening the render, but more importantly, slightly burning out the really bright highlights. The blur we added previously help soften and bloom the effect just a little.



Step 5 : Bring the Noise

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Now add a new layer via the Layer menu, and set the layer mode to Multiply. Also make sure yo tick the box to specify that the layer will be filled with a multiply neutral colour. We need this ticked because noise cannot be applied to an empty layer, and the neutral colour will be invisible (neutral white in this case).



Step 6 : Add and Adjust

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Apply the Noise Filter with a value of 4% Gaussian Monochromatic. This is my preferred setting, but you can experiment with different values. These settings for me seem quite subtle, but some people seem far less keen on noise being added. The advantage of adding it in a separate layer is that you can use the layer opacity to fine tune the visibility of the noise.



Step 7 : Colour Tint

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Now add a Solid Colour adjustment layer, selecting your tint colour, and setting the layer mode to Colour. An opacity of around 30% avoids overpowering the colours, but each render can vary of course.

Adding a tint to the render really transforms it. As with aberrations, it removes the perfect colours which our eye might not expect to see through a camera. It also affords you a chance to change the mood of your render by cooling it down or warming it up. I typically favour a slight green tint, almost as you’d get from some fluorescent lighting, however a warmer orange can enhance the lighting of the sun. My example with the Exige can be greatly varied in this way.



Step 8 : Vignette

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Now add a new layer via the layers menu, and select the mode as Overlay, and as we did with the noise layer, tick the box to have the layer filled with an overlay neutral colour. This will allow us to fine tune the strength of our vignette.




Step 9 : Lens Correction Again

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Apply the Lens Correction filter, ignoring all settings other than setting the Vignette Amount to -100% and leaving the Centre value alone, as we don’t want the vignette to be off centre.





Step 10 : Almost Done!

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I like to do wide screen renders, and you can create a much more cinematic effect by making your canvas standard HDTV resolution, in this case 1920×1080. This has the effect of giving us the familiar letterbox black bars, emphasising the wide aspect ratio of the render.




The Finished & Graded Render

[image_frame style=”framed” align=”left” height=”182″ width=”300″]http://www.scorpiocgi.co.uk/_old/wp-content/uploads/2011/06/LotusExigeGraded.jpg[/image_frame]

The completed render, looking just that little bit more convincing than the straight render. Of course what we are doing is exaggerating somewhat the optical deficiencies of our camera so as to make them a little more obvious, in much the same way that often small details such as panel shut lines on large ships need to be slight bigger than they would be in reality, to make sure the viewer sees them.

[download_box]Grab the Photoshop Action HERE[/download_box]


Car Set-up & Rendering Tutorial


I have covered topics of modelling wheels and tyres for cars, as well as grading renders. it seemed fitting therefore to also cover a quick mini-tutorial for setting up rendering of cars. The setting for car renders is highly subjective, and many people favour outdoor locations using HDRI maps for the lighting and environment. They certainly have their place, there is no denying, however I find the simplicity of a completely neutral environment hard to beat. It offers no distraction from the main subject, and shows the lines and beauty of the car like few other environments can.

So this then is how I do mine, producing clean renders in colour neutral settings. Of course the effective environment colour is yours to choose, white is just my preference.

Some Super Simple Modelling

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First things first is the unseen environment. In modelling terms, it doesn’t get much simpler. I made a large box structure, which truth be told needn’t be more than an actual box. I modelled mine curved, but for this rendering set-up, it actually doesn’t need to be. This initial outer box is the black void seen in reflections, and as such it’s surface attributes should be set as R:0 G:0 B:0 for colour and 0% for diffuse. Within this outer black box, I have added three rectangular panels, all the same lengths, but slightly varied widths. Their normals are pointing toward the 0,0,0 world centre. These panels will provide the white areas for reflections in the paint and on glass, but will also provide light. Surface attributes as a good starting point are colour R:255 G:255 G:255, diffuse 0%, and luminosity of 275%.


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The last modelling task is the ground. For this I create a plane which gently curves up in the background. This is a good generic ground that can be used outside of this type of scene set-up, as the ground also provides a backdrop. For this render the ground has colour set to R:140 G:140 B:140, diffuse of 100% and no specular or reflections.


Into Layout

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In order to give a little flexibility for tweaking post render, set the light panels and ground objects to be excluded from the alpha channel. Under object properties, make sure it says that the alpha channel in Unaffected by Object. This will ensure the alpha channel will only have the car in it. The other options can all remain as default.



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For the outer black box, untick the Cast Shadow, Self Shadow, and Receive Shadow. Make sure you tick Unseen by Camera and Unaffected by Fog. This means that the black box never directly shows up in view of the camera, and unaffected by fog means it will always be fully visible to reflections (otherwise all reflections would be white).



[image_frame style=”framed” align=”left” height=”182″ width=”300″]http://www.scorpiocgi.co.uk/_old/wp-content/uploads/2011/06/rendering_05.jpg[/image_frame]

With your car loaded in, we need to set fog as enabled. I always use the realistic mode, but for this purpose it really doesn’t make a vast difference. The fog is simply serving the purpose of blending the background and ground in to a unified background. To this end, ensure you have Use Background Colour ticked, and set the background colour in the scene to R:239 G:239 B:239.



[image_frame style=”framed” align=”left” height=”182″ width=”300″]http://www.scorpiocgi.co.uk/_old/wp-content/uploads/2011/06/rendering_06.jpg[/image_frame]

So what we now need to do is get or fog set right. You need to adjust the fog to kick in just beyond the boundary of the farthest most visible scene element. If you have the OpenGL set to show fog, you can see the fog clipping the car in the viewport. F-Prime or VPR will of course show the same thing rendered.



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Here the fog is now just beyond the far corner of the car. With the minimum and maximum distances almost the same, the fog creates a very distinct curtain, but you can expand the gap between them to create a more gradual blend should you wish some visible ground evidence behind the car.



The Finished Render

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The finished render which has also been graded. Read HERE to find out how.

Using Sliders in Lightwave


Sliders are a great tool in Lightwave for simple rigging tasks. They can be used for many applications, though for me, it usually involves simple rigs for vehicles. By using them in conjunction with Cyclist to control physical components of the car including steering, doors, wings, and also simple suspension moves, it enables you to quickly pose a car for a rendered still (or animation). They are fully key-framed, making them very powerful.

This mini-tutorial shows you the basics of how to set-up sliders for a vehicle, in this case the Bugatti Veyron.


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First quick task is to add a null for each element that we intend to animate and rig with sliders. Typically you would have steering and doors at the very least. The Veyron has some extras for it’s articulated wings. I am also going to add some nulls to control suspension in terms of the tail squat and nose diving, along with basic body roll. As I say, for full blown animation, you’d have proper automatic rigs, but for rendered stills these work great. All of these nulls can be left at world zero, as they are controlled via sliders once we are done, and are fine to be kept out of the way. Don’t worry if you miss one, you can add them at any time.


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The steering wheel generally required special consideration. It doesn’t sit flat on any one axis usually (unless you orientate it as such in modeller), so we need to add a null rotated to effectively sit flat on top of the steering column, and then parent the steering wheel to it. this will allow the steering wheel to rotate correctly.



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As mantioned in the introduction, we use Cyclist with Sliders. This means that for the main rear wing lift, we first keyframe the animation from the down position at frame 0, to lifted at frame 60 (you can use whatever end frame number you want).




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We now have the motion of the rear wing lift animated. Cyclist works by effectively playing back animation based on input from a control null. Open the Motion Modifier settings for the component, and apply Cyclist.




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In the Cyclist settings we specify which of our nulls will provide the input, as well as the start and end frame numbers for the animation range we want to use. You also specify the range of the control input, so 0 – 90° for example makes fine control easier than 0 – 30°. You will find the animation no longer works in layout when you scrub the time-line.



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For the doors also create an end key-frame with the door fully open. I haven’t any idea what angle car doors open to, I just use an angle that looks good. Do the same for the other door as well.





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Once again, we add Cyclist, using frame 0 through to 30, and control range 0 through to 90° of Heading on the Door Left control null we added earlier. Door movement is no tied to the Door Left control null and it’s heading rotation.




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I have set o to 90° as the rotational limits in the motion options for the null, and now when we rotate the null through that range, the door opens!





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Steering wheel is next. The wheel is parented to it’s null, and I animated this null to be banked at -170° at frame 0, 0° at frame 30, and 170° at frame 60. This gives the full left to right steering wheel rotation lock to lock. It is then linked to the steering control null with Cyclist using a control range of -90° to 90°. Frame range is the 60 frames that our lock to lock animation uses.


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Next we have the nulls that control the car nose diving and tail squatting. The nose diving null is located centrally between the rear wheels, and parented to it is the tail squat null. This null is located centrally between the front wheels. Started with the nose dive null at the rear, add a slight pitch of around -1° or -2°.



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Once again we link this to it’s control null with Cyclist, matching the frame range to that in the previous step, and specifying the range of movement for the control null (you’ll notice it’s normally based around a 90° range).




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Finally we have a null for body roll, which your nose dive null should be parented too (look at the scene editor in the example). As long as you make sure you have Parent in Place enabled in Layout, you can shuffle things around in your scene hierarchy without too much bother. As you see, I have animated body roll bank from -2° through to 2° and key-framed 0° midway.


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Cyclist is added in just the same way to the body roll null. We now have the ability to dip the front and rear of the car (indeed we can lower the car by adjusting both simultaneously). In addition we can roll the car body slightly either direction.




Add the Sliders

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Selecting your master car null (to which ALL vehicle related items are parented), open the properties palette, and choose Sliders from the Custom Object drop down menu. Then double click Sliders in the Custom Object List. You’ll be presented with the Sliders configuration, with a list of all scene items in the left side. Each item can be expended to show available channels such as X, Y, Z, H, P, and B etc..


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Find each of your control nulls, expand the channel for each and double click the channel you used for the Cyclist Control. Make sure the start and finish angle matches your Cyclist setting, and give it a custom label if you wish. Each slider will be assigned a different colour automatically, and you can override this if you want. You’ll see your floating list of Sliders grow as you add each one.


Using the Sliders

Using sliders is a breeze. When you want to make an adjustment, either hit your sliders hotkey, or go to the modify menu and select Sliders. You’ll notice that the Slider changes from a dotted line to a solid line. This shows you they are active. Then simply slide them and see your car components move.

A key-frame will be automatically created on any slider you move. If you hit the E envelope button, you’ll bring up a graph editor where you can adjust key-frames for any slider, and all the usual graph editor functions.

The four way arrow icon will let you drag the slider around the viewport (only when sliders are active), and the left/right arrow button allows you to stretch the width of the sliders on screen which can aid fine tuning (again only when sliders are active). You also have a single down arrow head which collapses and expands the sliders to de-clutter the screen.

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So this is the car with all the sliders added, and all left at zero with the exception of the rear wings which are in the deployed position.





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Now we have turned the steering hard right, dipped the nose of the car down slightly, and added some body roll. You can see the sliders that have been adjusted for this, and how simple it is.