CRI Sofdec(Unreal Engine) v1
Introduction 03 How to play Sofdec movies with transparency
A Sofdec movie with transparency is called a "Sofdec Alpha Movie" or simply an "Alpha Movie".
In this chapter you will learn how to play alpha movies.
Alpha Movie
An alpha movie contains transparency information (transparency value, alpha value, alpha channel) for each video frame.
The transparency information is decoded into the Sofdec movie data along with the regular video frames.
By entering this value into a material and using it, you can play and display a movie that allows you to see through to the background, as shown in the image below.
How to create an alpha movie
The basic method is the same as the Sofdec movie encoding method introduced in "Introduction 01 Simple playback of Sofdec movies".
To create an alpha movie, you must prepare 32-bit video material data that includes 8-bit alpha channel information. Start the "Sofdec Encoding Wizard" and specify a video file with an alpha channel on the "Specify input video material" page.
After selecting the file, check the "Alpha Movie" box. When doing so, make sure that the color depth is set to 32bit in the material information.
After setting the output destination and other encoding parameters, run the encoding and the alpha movie data will be created.
How to play alpha movies
This article explains how to attach an alpha movie to a Static Mesh and play it.
The procedure is basically the same as in "Introduction 01 Simple Playback of Sofdec Movies", but the specific steps are as follows:
- Drag and drop the alpha movie encoded in the Sofdec USM file format from Explorer to the Content Browser.
- Right-click on the generated asset and click “Create ManaTexture”.
- Right-click on the generated texture and click "Create Material" from the menu.
- You will be asked to select a material type, make sure "Alpha Channel Support" is set to "Automatic".
If you select Component Textures, the following material will be output.
If a black image like the one below appears, please play the level based on "Introduction 01 Simple Playback of Sofdec Movies."
The video will then load and an image will appear that matches the video.
If you select Render to Texture, the following material will be output.
The subsequent steps are the same as those explained in "Introduction 01 Simple Playback of Sofdec Movies."
