The issue you're experiencing with alpha value animation in Unreal Engine is likely related to differences in color space and blending modes between Spine and Unreal Engine. In Spine, you might be using gamma space rendering, while Unreal Engine uses linear color space by default. This can cause discrepancies in how alpha values and colors are interpolated and displayed. To address this, you can try switching Unreal Engine's rendering pipeline to gamma space or previewing the blending in Spine 4.0-beta with linear blending to match Unreal Engine's settings. Additionally, ensure that your texture atlas is exported with the correct alpha settings, such as premultiplied alpha, to match Unreal Engine's expectations.
