Is there any way adding hemispherical light or Environment light without affecting the blackness of the shadow

Hello.In the process of making a large 3D scene, it is often necessary to have a directional light, and add a hemisphere light or Environment light to light the place where the directional light does not shine, such as the back of the house.
However, adding hemispheres or Environment light can cause the shadows to become very faint, even if the Intensity increases only a little. I want to ask is there any way adding hemispherical light or Environment light without affecting the blackness of the shadow.

PG:https://playground.babylonjs.com/#IFYDRS#722