Join Brian Bradley for an in-depth discussion in this video Overview of the V-Ray Physical Camera, part of SketchUp Rendering Using V-Ray 2.
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- Given that modern 3D applications and render engines are more often than not these days employed as virtual photography studios, it is fitting that V-Ray office uses an extremely photographic approach to taking rendered images in the form of the V-Ray Physical Camera. The cool thing here is that because this camera model adheres very closely to the workings of the real thing, any familiarity we have with using the controls of either a film or a digital camera will be a real help to us when it comes to working with the V-Ray Physical Camera's controls.
If, however, we are somewhat unfamiliar with how to use a camera's controls, or even if we would just like a little bit of extra help when it comes to working with the V-Ray Physical Camera, I would highly recommend that you watch Ben Long's excellent Foundations of Photography series found here on Lynda.com. Seeing as lots of the material that Ben covers in those courses can be transferred straight over to use with the V-Ray Physical Camera. That having been said, what we want to do in this video is take a quick overview of some of the controls that the V-Ray Physical Camera makes available to us.
To access those, we of course need to open up the options dialog where we can jump into the camera roll out. In here we have quite a number of options that ultimately combine to give us a ton of control over the rendering camera in V-Ray, with the majority of the physical controls being housed in this Physical camera grouping. Although, if we take a look down below, we see that we also have depth of field, bokeh effects, and motion blur options that each have their own control groups. The first option we have on the physical camera is the ability to control the on/off state for it.
In other words, we don't have to render using a real-world camera model if we don't want or need to. Just below this toggle, we're given the ability to set the type of camera that we want to work with; still, movie, or video. If you keep your eye on the shutter and latency controls as I cycle through each of these options, you can see that what we get are different sets of control options opening up to us. Changing the camera type essentially alters the way in which the camera model simulates shutter behavior, meaning this option will mainly affect any in-render motion blur that we decide to add.
The still camera has been designed to simulate a typical still photo camera meaning it makes use of a regular shutter speed value that works in fractions of a second, just as you would find on a digital SLR or point and shoot camera. The movie option simulates a motion picture camera and makes use of a circular shutter which means we lose the shutter speed control and instead gain shutter angle and shutter offset options; both of which work using values in degrees of rotation. With the video camera model, we get something that simulates a shutter-less video camera using a CCD matrix and the only extra control we have to work with is that of the CCD matrices latency, which again is set using a value in terms of seconds.
All we need to do here is choose the type of camera that we want to work with, which typically speaking in SketchUp is going to be the default still option and we're good to go. Although, if we have a need to match the effects of a particular shutter type in the camera model, then these options are very obviously, ready and waiting to be used. The zoom factor tool is interesting in that it gives us the ability to add an offset to our current zoom level as seen in the SketchUp view port. If we increase the value found here, what we get is an increased zoom level in our final renders.
This doesn't affect our SketchUp view port as it is a render time only effect. And because we are working with a physical camera model, we would perhaps expect to have to work with exposure controls just as we do on a real-world camera. And that is exactly what we can do using the V-Ray Physical Camera. Indeed, just as other real-world camera, we have three exposure parameters with which to deal. F-number or F-stop, film speed or ISO control, and of course the shutter speed, although as well as controlling exposure, we do have to keep in mind that two of these options, namely shutter speed and F-stop also control other elements in our final rendered frames.
The F-stop or F-number will control the field. And the shutter speed will be used to handle motion blur. Not that we're forced to work within camera exposure. We could if we wanted, disable the check box that we see here and now the three parameters that we just mentioned will no longer affect the overall brightness of our image. We would now have to control this by means of color mapping and individual light intensities. Another effect that we can burn into our final renders with the physical camera is that of vignetting.
That darkening around the edges of a photograph that we often times see because of the particular way in which a camera lens has been manufactured. Personally, I would recommend adding such effects in a post production application such as Photoshop, seeing as we have much more control and flexibility over the final vignetting effect there. A common control found even on many cell or mobile phone cameras these days is that of white balance. This option gives us the ability to set which of the colors found inside our image are to be considered as the white point.
We do need to note though that only color hue is taken into account here. The brightness or value of a color is completely ignored in this particular setting. As the lens shift control is something that we are going to be looking at in a later video, we can jump over this particular option for now and have a look instead at the distortion control. This, as the name suggests, gives us the ability to add lens distortion to our final rendered images, meaning we can more closely match the effects of a camera lens that we may have used in shooting our background plates for instance.
Positive values give us barrel distortion, whilst negative values will produce pillow or pinched distortion. As you can see then, the physical camera definitely offers a genuinely photographic approach to rendering in V-Ray offering lots of control over the entire process. Indeed, having the ability to take real-world photography experience and apply that to our work in a 3D rendering package has some clear and obvious benefits. Given that anything we learn in real life, even whilst using a modest point and shoot or cell phone camera, can be taken and then applied to our work inside of V-Ray.
And of course the opposite also applies. Anything we learn inside V-Ray can also be taken out into the real world and then applied to our efforts at real-world photography. Fair exchanges they say is no robbery at all.
- Locating V-Ray tools and features
- Using the RT Engine
- Creating daylight with V-Ray Sun and Sky
- Using image-based lighting
- Working with irradiance mapping
- Handling perspective correction in the physical camera
- Setting up a depth of field effect
- Creating and applying V-Ray materials
- Using fixed-rate sampling
- Color mapping
- Working with V-Ray proxies