このプロパティーの値にハイダイナミックレンジ (HDR) データが含まれていることを示します。
When this flag is set, the default material inspector will display warning if incompatible data was assigned in the Material. For instance default material inspector will warn and suggest to fix the texture that contain alpha channel (unsupported in HDR textures). This corresponds to "[HDR]" attribute in front of property in the shader code.