There are people who aspire to achieve a fantastic and whimsical look for their 3D rendered images, achieving photorealistic results is still considered the "holy grail" of the rendering world.
So if you are looking to create some unique 3D indoor shots and 3D outdoor shots, here are some tips on how to achieve this lifelike effect.
Change Your Lighting: As any artist knows, lighting is crucial for any 3D rendering. Play with and experiment with lights that represent different times of the day. To make the scene look like an ultra-realistic 3D exterior rendering, take some suggestions from online sources.
Fix the problem: Use 2D photo editing software to add objects like real pictures of trees, bushes, and people to your interior and exterior 3D images.
Create reflections: Examine every object in your scene and analyze which ones would normally have reflective surfaces. Some examples are bodies of water, shiny ground, and the metallic surface of a car. Creating highlights for these will do wonders to make your rendering look realistic.
Drop Shadows: Shadows add depth to the scene and are essential for a natural appearance. Adjust the lighting to get a good play of light and shadow in your view.
Making it too sunny for a 3D exterior shot or inserting too many light sources in a 3D interior shot reduces the number of shadows so that the final image looks very flat. This is why it is important to choose the optimum amount of lighting for your 3D rendering.