Animations

Tutorial 7 in the Basics of Twilight Render V2 Series

Both Twilight Render V2 Hobby and Pro support rendering Animations.  SketchUp provides a great deal of features in support of animations, including changing environment lighting, layer visibility, and camera settings.  With the addition of third-party plugins, it's also possible to animate geometry and even perform physical simulations!

Animations in SketchUp are scene-based where each scene page represents a stopping point and your animation is a transition between points.  There are many tutorials and guides available on the internet to learn how to create a SketchUp animation.  If you are new to SketchUp animations, we strongly recommend you take some time to learn how to create animations in SketchUp before attempting to render them!

Once you have your animation ready in SketchUp and it's time to begin rendering, you start with the Twilight Render Animation Editor.  You can find the Animation Editor under the Extension menu (SU 2015) or the Plugins menu (SU 2014 and earlier), by clicking Twilight V2, then Animation Editor.

The animation editor is very similar to the standard Render Editor.  From it you can set the Render Preset, the Image Size, various Camera properties, and Layer visibility.  You can find a tutorial on all these under the Basics of Rendering Tutorial here.  Almost all the settings are exactly same and used the same way.  There is the addition, however, of three (3) specific controls that you will need to use for setting up your animation.

The first is the Animation Advanced Settings.  You can see this in the Animation Editor under the Advanced drop down (right in the middle of the editor's Toolbar).  Under the dropdown you will find all the controls necessary for setting up your animation, including the length of time to run, the number of frames per second (FPS) and where to save the finished images.

Let's look at the different settings available.

• Animation Type - Twilight Render V2 provides 3 different ways of moving the camera through your animation.  Selecting from the Animation Type sets which method to use.
  • Sketchup Scenes - The camera will progress along the exact same path that SketchUp follows when it shows the animation in the SketchUp view.  This method is characterized by sharp corners that may be unsuitable for a walk-through.  But if you are animating geometry from a single viewpoint, this would be the best method to choose.
  • Smooth SU Scenes - The camera will progress along the same SketchUp path, however the corners of the path will be rounded out.  Transitions between scene are still noticable but smoother.  This method is better suited for walk-through animations.  Be aware, however, that the camera placement especially around corners may be slightly different than it's original placement in SketchUp.
  • Smooth Curves - The camera will progress along a smooth, seamless curve through all the scene points.  Transitions between scenes are completely unnoticable in most cases and the progression is very smooth.  This method is best suited for a fly-through or orbiting a single viewpoint.  It is important to note that the smoothed camera position may not fall where you expect; it is important to preview your animation path before rendering (more on that below).
• Start Time and End Time - SketchUp animations are time-based.  The amount of time to transition between two SketchUp scenes is set in SketchUp under View->Animation ->Settings.  It is very important to note that the transition time between each scene is exactly the same regardless of how far apart the camera positions are.  Knowing that, the Start and End Times for rendering your animation correspond exactly to the time in the SketchUp animation progression.  Typically you will start your animation at 0 seconds (however you can choose any time).  Your end time can be any time after the start time.
  You might notice a description label above the Start and End Time.  This is very useful for telling you how long the SketchUp animation is and how many frames are expected to render using your current settings.
• Frame Rate - The number of frames (renders) per second of animation is set by the Frame Rate (FPS).
• Base Image Name - In order for Twilight Rendr to know where to save your rendered images, you must specify a directory and filename to use.  All rendered images will be saved to the same directory, using the file name as the base name and appending the image's frame number (1,2,3,4,etc) to the file name.  Most frame-to-video software expects images to be sequentially numbered in this way.
• Starting Index # - If you want to start the frame number that your saved images start at, you can change this value.  This is very useful if you are creating an animation from several different renders as it allows you to pick up where the last one left off.
• Reuse Lighting Information - This is a very important setting for animations when using photon-mapping render presets (Low/Low+ through High/High+).  Part of the render process includes something called Photon Mapping.  Normalling each render recreates the Photon Mapping.  During an animation, this can cause the lighting to flicker, especially in poorly lit areas of the render.  By checking the Reuse box, the Photon Mapping will only be calculated one time and reused for each subsequent render in the animation.  The will prevent the flickering. 
  However, it is important to know that this can only be used if you are not modifying any geometry during the animation, including hiding/showing geometry, enabling/disabling layers, or animating components or groups.  To enforce this, the Reuse Lighting Information option will only be used if the Content setting (found in the Animation Editor toolbar) is set to Camera & Lights or Camera Only.
• SketchyPhysics - SketchyPhysics is a physical simulation plugin (installed separately) that Twilight Render can integrate into its animation renders.  By enabling it, any SketchyPhysics components in your scene will progress 1 frame per rendered frame.  This can create excellent realistic effects for collisions and moving parts.  Please note that currently SketchyPhysics is not supported by SketchUp 2015 x64 as development of the plugin has been suspended.  Future versions of Twilight Render may remove this feature if SketchyPhysics remains unavailable.
• Start SP at Frame - This allows you to pre-warm the SketchyPhysics simulation by advancing it to a specific frame number before animation rendering begins.

Once you have your animation set, you can choose to preview what your final animation will look like.  Twilight Render V2 provides two tools to help you visualize your animation before commiting to a long render.

The Animation Path button (the film strip button in the Toolbar) displays the 3D path that the camera will take as it moves through the scene.  It will also display a 3D path of the camera's target (where the camera is looking).  Along the path are dots indicating where the camera will be at each frame.

The preview path shades from Blue at the start to Purple at the end (The target path will shade from Green to Yellow).  As you can see, the different Animation Types produces paths of varying smoothness.  The preview path tool is a great mechanism for ensuring your camera view won't fly through (or too close to) any geometry during the render.   By observing the target path, you can also ensure that your camera is viewing the correct target.  This is especially important when using Depth-of-Field where the target point is the focus of the camera!  Note that the best way to set the camera target is to use the Twiligh Render View Tool and use Ctrl or Alt+Ctrl to set the focal point in every scene.

The other tool is the Animation Preview.  Pressing the preview button (the film strip and play button in the Toolbar) will position the SketchUp view along each render point in the path.  A small window will open from which you can cancel the preview at any time.  When the preview is complete, the window will notify you.

When rendering an animation with Twilight Render, there are some optimization features you should pay careful attention to, and these option depend entirely on whether you are rendering animated geometry, or just the camera for a simple walk through.

• Each rendered frame can reuse the existing geometry from the frame before it, or it can reload the geometry from scratch.  To set what scene information is reloaded, you will need to set the 'Content' setting of the Animation Render Editor.  When set to 'All', all geometry, lights, camera, etc. is reloaded on every frame.  When set to 'Camera', only the camera position is changed on each frame.  If you wish to render animated geometry, you must set 'Content' to 'All'.
• If you are only animating the camera, you can improve render times considerably by checking 'Reuse Light Cache'.  This allows Twilight Render to reuse certain lighting information and can improve the quality of your render as well.  This option can only be used, however, when 'Content' is set to 'Camera'.  If you are not using this option, we recommend using one of the Animation specific render presets.
• Please note that 'animated geometry' refers to any change in geometry, and this can include not just moving geometry, but changes in layer visibility from scene to scene as well.

There are a few important points to be aware of when rendering an animation in Twilight Render.

• When rendering a single image, Twilight Render makes it easy to continue working on your SketchUp scene while the render is running.  With animations, however, this is not advised.  Because the animation sequence moves the SketchUp view with every render and potentially reloads the geometry in every frame, trying to work while the animation is rendering will prove challenging at the least, and may end up ruining your animation.
• Twilight Render installs a set of Animation Presets under Render Settings -> Express -> Animation.  These presets are designed for rendering animations with moving geometry.  They have been modified to reduce the photon map flicker that will result from not having "Reuse Lighting Information" available when updating geometry in each frame (Content set to All).  They will perform better and render more quickly, however the trade off is that indirect lighting in your scene will be reduced.
• Face-Me components are a form of  animated geometry.  This means that if you want your Face-Me components to update with each scene (and face the camera), you will have to set Content to All.  This also means you will not be able to use the "Reuse Lighting Information" option and will likely need to use one of the specialized Animation presets.
• There are many geometry animation plugins available for SketchUp.  As long as the plugin works with SketchUp's built in scene animations, it should work with Twilight Render.  However, no guarantee is made for compatibility with an given third-party plugin.
• Rendered Section Planes do not work by default with Twilight Render Animation!  The mechanism used by SketchUp to "animate" Section Planes is specific only to SketchUp's internal scene animation.  The way Twilight Render steps through the animation sequence breaks the Section Plane animation.  Instead, Twilight Render provides an alternative Section Plane Object (for licensed Pro users).  Section Planes can be converted to the TWR Section Plane Object which can then be animated as a component (along with the other Section Objects, cube, sphere, and cylinder).

As you can see, animation with Twilight Render is very simple and integrates well with SketchUp's built in scene animation.  With just a few settings you can turn your SketchUp walk-through into a great video presentation.