You may encounter a situation where when using a large number of video transitions in the project, the rendering speed drops. If you are a professional in the field of video processing and animation, then you probably know how everything works and that this is a normal situation. However, if you are only taking your steps in After Effects or Premiere Pro, the information below will help you clarify why this happens and that in general this is a standard situation in the field of video processing and animation.
First of all, the duration of your video affects the rendering speed and how many transitions are used, and how complicated are these transitions. Since, depending on the effects and components used, the transition can be both easy and fast, as well as heavy and slow. For your understanding of transitions, these are not just effects. In most cases, these are manipulations/transformations directly with both footages. And often, each of the manipulations requires computer resources, since at least all the transformations are performed mainly with Full HD resolution (1920 x 1080). Below is a small list of effects or transformations for an example, so that you understand why this affects the rendering speed of the final video.
- In almost all transitions there is simulation of Motion Blur (Shutter Angle option which controls the Motion Blur).
- Using Transform effect which performs geometric manipulations. And often such effect can be used a lot for one transition, where the settings of each are responsible for certain transformations with a footage.
- Using effects like Optics Compensation (introduce or remove lens distortion) that affect render speed.
- Using heavy effects like Glow
- Using Motion Tile effect which can duplicate a footage, for example, for a mirror effect. Especially if the output footage can be increased by 100-300%.
- Using 3D layers or Camera layers which have a focus distance.
- And, finally, when rendering the project, the Motion Blur option is automatically turned on.
Depending on the number of similar effects that the transition design will require, the complexity of calculations may form, so it takes longer for the render, which calculates all these manipulations and transformations with footages. In addition, it depends on the configuration of the computer and the resources available to the After Effects.