Join Brian Bradley for an in-depth discussion in this video Adding aerial perspective, part of SketchUp: Rendering with V-Ray 3.
- [Instructor] Whenever the term aerial perspective is mentioned in connection with rendering, most people tend to think of shots that involve distant mountains with that lovely blue haze covering them, a visual clue that essentially says that what we're looking at is really quite far away. Well, whilst aerial perspective can certainly be used for shots like that, we're actually going to show how the feature works using this much more enclosed courtyard space because even on renders like this the aerial perspective tool can be put to good use.
As already noted, the tool essentially mimics the effect that the earth's atmosphere has on the appearance of objects when viewed from a distance, similar in many respects to fog or haze. The effect works together with the V-Ray sun in a scene in order to calculate an approximation of aerial perspective. I say approximation because aerial perspective can't, at the time of this recording, produce something like volumetric shadows in V-Ray for SketchUp. As we already have a render of our scene in its current and default state saved to the history list, let's go ahead and take a look at enabling the aerial perspective effect which we can in fact do in two ways, the most obvious being to come into the environment rollout in the settings tab of the Asset Editor and simply turn the option on.
What we can also do though is use SketchUp's own fog controls to both enable and in a limited way control aerial perspective in the scene. Coming to the View menu in SketchUp then, let's make sure that fog is enabled which as you can see in the Asset Editor does indeed turn the aerial perspective effect on. We can then in our default tray make certain that the fog controls are showing up. With a basic visual representation in the view port now we can quickly and easily create a starting point for our atmospheric effect that we can then fine tune in the V-Ray Asset Editor.
In fact, as I drag the near and far distance sliders around in the SketchUp controls, you can see how they are updating the visibility range option in the V-Ray UI. Something else that we may have noticed as we enabled the fog option in the SketchUp View menu was that the filter color found in the aerial perspective rollout changed from white to green so as to match SketchUp's view port representation of the fog. Now, this will be the color that shows up in our V-Ray renders and so, we will want to remember to switch it back to something more appropriate for our scene once we have done with the testing phase that is.
In fact, I'm going to go ahead and do that right now. After setting our visibility range back to the default of 6,000 then, let's go ahead and take a render and see what we get which as you can see is a very obvious hazing of the entire localized environment. The visibility range control specifies the distance in meters at which the fog will absorb 90% of the light coming from objects behind it. Lower values make the fog appear denser, whilst larger values reduce the effect and so make the fog appear lighter.
You will have noticed though, assuming you are working through this course with me, that the render there took quite a while to complete as compared that is to the scene with no aerial perspective enabled which isn't surprising really given that V-Ray is now having to calculate the scattering of light in the atmosphere. To gain a little more speed from the system, we may want to lower the in scattered light multiplier value that controls the amount of sunlight scattered by the atmospheric effect.
The default of one is physically accurate but lower or higher values could be used in order to give us the effect that we want with lower values of course giving us less accuracy in the scattering and so more speed in the rendering. Something else we can do if I just switch over to scene one here, re-enable aerial perspective and then make sure that we are using a white color is create a much more localized effect by setting the visibility range to say 100 and the height to one.
If we render now, you can see that we have the beginnings of an interesting ground fog effect. Clearly then the aerial perspective tool in V-Ray for SketchUp 3 is capable of much more than just helping us create pretty shots of distant mountains.
- Gamma handling in V-Ray 3 for SketchUp
- Working with interactive rendering
- V-Ray light types
- Working with irradiance mapping
- Rendering animations
- Working with the V-Ray camera
- Using the Materials UI
- V-Ray FX tools
- Stereoscopic 3D rendering
- Using V-Ray objects