Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member

Handling perspective correction

From: SketchUp Rendering Using V-Ray

Video: Handling perspective correction

Oftentimes, when producing visualization renders, a SketchUp artist maybe asked to mimic the use of a perspective control or shift lens as employed by many visualization photographers. These lenses can actually be moved parallel to a camera sensor. The basic idea being that they give a photography ability to control the appearance of perspective in an image. Architectural photographers often use this functionality to avoid convergence of the vertical lines in tall buildings, but of course the functionality can be used to straighten the verticals in any perspective photograph.

Handling perspective correction

Oftentimes, when producing visualization renders, a SketchUp artist maybe asked to mimic the use of a perspective control or shift lens as employed by many visualization photographers. These lenses can actually be moved parallel to a camera sensor. The basic idea being that they give a photography ability to control the appearance of perspective in an image. Architectural photographers often use this functionality to avoid convergence of the vertical lines in tall buildings, but of course the functionality can be used to straighten the verticals in any perspective photograph.

If we take a render of our perspective start scene, we may see why this piece of functionality, the ability to straighten verticals, could be a desirable to for our rendering process. Straightaway we can see that we have a number of lines in our rendered image that are leaning quite badly. This perhaps may not be what our client expects. They want to make certain that all of the verticals in their architecture really do look vertical. Now you may be thinking well, that isn't a problem, because SketchUp has perspective correction tools of its own.

Well, that it true; the problem is V-Ray does not work with them. At render time we would still have an image identical to that scene in the V-Ray Frame Buffer this moment in time. The good news is that V-Ray does give us a tool of its own with which we can work. To access it, we need to come up to our Options Editor, or Options dialog, and into the Camera rollout. The control we want to work with is down in the CameraPhysical group. It is this Lens Shift option that we did say we would be coming back to.

Now as you would expect from a single parameter, this tool works in a very simple way. Positive numbers cause our vertical lines to diverge. This makes objects appear to lean towards the camera. Negative values will force them to converse, or appear to lean away from the camera, which is the problem see in our current render. Now, for your scene, where we are using a 30 mm lens setting, a Shift value of about 0.23 ought to be sufficient to make our lines appear to stand vertical. With that change, we can dismiss our Options dialog.

Now if you're not certain which lens settings you are working with, or rendering with, inside SketchUp at this moment in time, if you just come across to the SketchUp Zoom tool, left- mouse-click on that, you'll see over here, in the bottom right- hand corner of the interface, we get a readout in millimeters of our current focal length. Now of course, we need to take another render to see if that has corrected our problem, which of course, it clearly has. It has been said, oftentimes the simplest tools save us the most time.

Now we could've performed these perspective corrections in an image editing application such as Photoshop, but as we have such an easy-to-use and readily accessible control on our V-Ray Physical Camera it makes sense to use it. It makes for easy perspective correction, taken care of right here at render time.

Show transcript

This video is part of

Image for SketchUp Rendering Using V-Ray
SketchUp Rendering Using V-Ray

33 video lessons · 6027 viewers

Brian Bradley
Author

 
Expand all | Collapse all
  1. 4m 30s
    1. Welcome
      1m 14s
    2. What you should know before watching this course
      2m 33s
    3. Using the exercise files
      43s
  2. 7m 52s
    1. Installing V-Ray
      2m 27s
    2. Locating V-Ray tools and features
      5m 25s
  3. 39m 2s
    1. Creating natural daylight with the V-Ray Sun and Sky
      7m 41s
    2. Using the Omni Light
      7m 9s
    3. Exploring the Rectangle Light
      6m 2s
    4. Exploring the Spotlight
      4m 37s
    5. Exploring the IES light type
      5m 0s
    6. Setting up image-based lighting
      8m 33s
  4. 29m 40s
    1. Working with irradiance mapping
      12m 8s
    2. Creating a light cache solution
      6m 14s
    3. Using the DMC engine
      11m 18s
  5. 23m 11s
    1. Overview of the physical cameras
      5m 16s
    2. Understanding the Exposure controls
      6m 23s
    3. Handling perspective correction
      3m 4s
    4. Setting up for a depth-of-field effect
      8m 28s
  6. 44m 59s
    1. Introduction to V-Ray-specific materials
      9m 41s
    2. Creating diffuse surfaces
      9m 44s
    3. Creating reflective surfaces
      8m 2s
    4. Creating refractive surfaces
      9m 53s
    5. Creating translucent surfaces
      7m 39s
  7. 44m 8s
    1. Using fixed-rate sampling
      10m 21s
    2. Working with the Adaptive DMC engine
      11m 48s
    3. Controlling the Adaptive Subdivision sampler
      10m 15s
    4. Exploring subdivs and the DMC Sampler controls
      5m 52s
    5. Manipulating color mapping
      5m 52s
  8. 33m 39s
    1. Adding displacement to materials
      10m 48s
    2. Using caustic lighting effects
      7m 37s
    3. Creating occlusion effects
      8m 13s
    4. Creating a non-photorealistic render (NPR) with the Toon material
      7m 1s
  9. 1m 21s
    1. What's next?
      1m 21s

Start learning today

Get unlimited access to all courses for just $25/month.

Become a member
Sometimes @lynda teaches me how to use a program and sometimes Lynda.com changes my life forever. @JosefShutter
@lynda lynda.com is an absolute life saver when it comes to learning todays software. Definitely recommend it! #higherlearning @Michael_Caraway
@lynda The best thing online! Your database of courses is great! To the mark and very helpful. Thanks! @ru22more
Got to create something yesterday I never thought I could do. #thanks @lynda @Ngventurella
I really do love @lynda as a learning platform. Never stop learning and developing, it’s probably our greatest gift as a species! @soundslikedavid
@lynda just subscribed to lynda.com all I can say its brilliant join now trust me @ButchSamurai
@lynda is an awesome resource. The membership is priceless if you take advantage of it. @diabetic_techie
One of the best decision I made this year. Buy a 1yr subscription to @lynda @cybercaptive
guys lynda.com (@lynda) is the best. So far I’ve learned Java, principles of OO programming, and now learning about MS project @lucasmitchell
Signed back up to @lynda dot com. I’ve missed it!! Proper geeking out right now! #timetolearn #geek @JayGodbold
Share a link to this course

What are exercise files?

Exercise files are the same files the author uses in the course. Save time by downloading the author's files instead of setting up your own files, and learn by following along with the instructor.

Can I take this course without the exercise files?

Yes! If you decide you would like the exercise files later, you can upgrade to a premium account any time.

Become a member Download sample files See plans and pricing

Please wait... please wait ...
Upgrade to get access to exercise files.

Exercise files video

How to use exercise files.

Learn by watching, listening, and doing, Exercise files are the same files the author uses in the course, so you can download them and follow along Premium memberships include access to all exercise files in the library.


Exercise files

Exercise files video

How to use exercise files.

For additional information on downloading and using exercise files, watch our instructional video or read the instructions in the FAQ.

This course includes free exercise files, so you can practice while you watch the course. To access all the exercise files in our library, become a Premium Member.

Join now "Already a member? Log in

Are you sure you want to mark all the videos in this course as unwatched?

This will not affect your course history, your reports, or your certificates of completion for this course.


Mark all as unwatched Cancel

Congratulations

You have completed SketchUp Rendering Using V-Ray.

Return to your organization's learning portal to continue training, or close this page.


OK
Become a member to add this course to a playlist

Join today and get unlimited access to the entire library of video courses—and create as many playlists as you like.

Get started

Already a member?

Become a member to like this course.

Join today and get unlimited access to the entire library of video courses.

Get started

Already a member?

Exercise files

Learn by watching, listening, and doing! Exercise files are the same files the author uses in the course, so you can download them and follow along. Exercise files are available with all Premium memberships. Learn more

Get started

Already a Premium member?

Exercise files video

How to use exercise files.

Ask a question

Thanks for contacting us.
You’ll hear from our Customer Service team within 24 hours.

Please enter the text shown below:

The classic layout automatically defaults to the latest Flash Player.

To choose a different player, hold the cursor over your name at the top right of any lynda.com page and choose Site preferencesfrom the dropdown menu.

Continue to classic layout Stay on new layout
Exercise files

Access exercise files from a button right under the course name.

Mark videos as unwatched

Remove icons showing you already watched videos if you want to start over.

Control your viewing experience

Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.

Interactive transcripts

Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.

Are you sure you want to delete this note?

No

Your file was successfully uploaded.

Thanks for signing up.

We’ll send you a confirmation email shortly.


Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

Keep up with news, tips, and latest courses with emails from lynda.com.

Sign up and receive emails about lynda.com and our online training library:

Here’s our privacy policy with more details about how we handle your information.

   
submit Lightbox submit clicked
Terms and conditions of use

We've updated our terms and conditions (now called terms of service).Go
Review and accept our updated terms of service.