For the realistic and immersive experience in a virtual environment, it is important to estimate and reflect the acoustic characteristic of the real indoor scenes. This article proposes a method of directly measuring the reflection coefficient of a surface, which is an acoustic characteristics in the real environment. Because expensive optimization-based studies that mainly aim to reproduce recorded sounds indirectly estimate acoustic materials, new estimates are required whenever the actual environment changes. Our approach utilizes the method of the acoustics field to enable anyone to easily and directly measure the reflection coefficient of a real environment and generate sound in a virtual environment. We obtain the impulse response (IR) for the target surface, separate the direct sound and the reflected sound, and calculate the reflection coefficient for each surface. The measurement of the IR and the reflection coefficient calculation takes about 2 s. Our result produces a sound with a similar reverberation time to the sound recorded in the real environment.