Join Brian Bradley for an in-depth discussion in this video Rendering animations, part of SketchUp: Rendering with V-Ray 3.
- [Instructor] One of the things that will always bring a little extra quality to our SketchUp projects is the addition of camera motion or animation. The problem so far as animation goes though is that sampling for the light cache GI engine which is of course set up as the secondary ray engine by default in our SketchUp scenes is view dependent, meaning it will only place GI samples inside the rendering camera's field of view. If we move the camera once the GI has been calculated, then the solution becomes unusable as it will now contain unsampled areas or gaps if you like.
Of course, once we move the camera and render again, we get a new set of irradiant samples calculated which could cause us to think that we don't really have a problem until we realize that is that the various sets of samples have no connection or correlation to one another whatsoever. The same object rendered from two different camera locations or on different frames will receive a completely different and unconnected set of samples resulting in samples that actually jump around from frame to frame.
This in turn can cause very unpleasant flickering effect in our GI solution. Now, fortunately the light cache system does have a sampling mode that has been designed to work with moving cameras and can be found in the disk caching rollout. This is the fly through mode. The problem with using this though is that it can take quite a bit of trial and error in order to find the settings that work optimally in our particular scene. As machine time as in rendering is typically speaking much cheaper these days than man or artist time, it does oftentimes make more sense to simply go ahead and render our animations using just the brute force engine in both the primary and secondary ray slots.
Of course, the first thing we will need in our scene is some animation to render, so if for instance, we have two scene views that we can nicely transition in between. As animation is hard coded at 30 frames per second, there is nothing we can do to alter that but one thing we will probably want to change in SketchUp's animation preferences is the initial delay setting which we have in fact set at zero here so that we get straight into the camera animation when rendering so we have no hold frames at all.
Next up in the render output rollout of the Asset Editor, we need to enable both the save image and animation options. We want to add a file path for our animation, so I'm going to go to the animation folder inside the exercise files directory and just call this animation.png, the brilliant thing here being that V-Ray will automatically append a .0000 to our file name and then use that number sequence to add the animation frame numbers to our images.
In the animation section, we can choose to render out the entire animation sequence if we want or we can choose to render a particular frame range if we only need a portion of the animation to be rendered to disk. Something I do like to do here is work with motion blur turned on as this not only helps add quality to the look of our camera move, but can also help hide possible noise problems in the render and given the sampling levels that we will be working at, this really doesn't add anything significant to our render times, although you of course prefer to add motion blur as a post-production process.
The settings that our current exposure value gives us though produce a motion blur effect that is way too strong for my liking. To control motion blur then, we're going to want to switch our standard camera settings over to the advanced UI layout and increase our shutter speed value which is the controlling mechanism for motion blur on camera. We can set this to something like 450 with higher numbers producing less and less of a motion blur effect. Of course, we will need to compensate for the exposure change that this will cause and so, let's set our F number to 10 in order to let more light into our virtual camera.
All we need do now is hit render and our image files will be rendered to disk, although we will of course need to pull these into a video editing or compositing application and then render them out so that we can enjoy the fruits of our labors.
- 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