Forward Rendering

In forward renderingA rendering path that renders each object in one or more passes, depending on lights that affect the object. Lights themselves are also treated differently by Forward Rendering, depending on their settings and intensity. More info
See in Glossary mode HDR is only supported if you have a post-processing effect present. This is due to performance considerations. If you have no post-processing effect present then no tonemapping will exist and intensity truncation will occur. In this situation the scene will be rendered directly to the backbuffer where HDR is not supported.