Scene Optimization

Optimizing the 3D scene you’re working on is one of the most effective ways to speed up rendering in Blender. In this article we outline a couple of the most effective ways to optimize your scene:

Reduce the number of objects, materials, and lights in the scene:

‍The more objects, materials, and lights that are in the scene, the more processing power is required to render the image. Try to simplify the scene by removing unnecessary elements or combining similar objects. For example, you can use the “Merge” tool to combine objects that are close together or use the “Boolean” modifier to create complex shapes from simpler ones.

If you’re using many of the same or similar objects, you should really see if you can use instancing. Instancing is particularly useful when you have a large number of similar or identical objects in your scene. A good example is a field of grass or a forest. In these cases, having the render engine re-compute every blade of grass, or every tree in a forest respectively, is very computationally expensive and will make your graphics card work overtime.

By using instancing in such cases, your renders will speed up drastically because it allows you to create multiple copies of a single object without increasing the overall number of objects in the scene; this will decrease the sheer amount of VRAM that must be used on the GPU when rendering your field of grass. When you have multiple copies of the same object in your scene, the rendering engine must process and render each individual object, which can take a significant amount of time. By using instancing, you can create multiple copies of an object using a single, underlying object, which reduces the overall number of objects in the scene and can improve render times.

In these cases, using instancing can significantly reduce the overall number of objects in the scene and improve render times.

To use instancing in Blender, you can select the object that you want to use as the base for the instance, then choose Object > Instance from the menu. This will create a new object that is a copy of the original, but any changes you make to the original object will be reflected in all of the instances. You can also use the Duplicate Linked tool to create instances of an object, which is found in the Object menu or by pressing Shift + D.Another approach you should use is instancing. You can also use the “Layers” feature to hide or isolate objects that are not needed in the final rendering.

Use simple materials and setups:

‍Complex materials and light setups can be computationally intensive and may slow down the rendering process. Try to use simple materials and light setups where possible. For example, you can use the “Diffuse” shader for most surfaces and the “Emission” shader for simple light sources. You can also use pre-made materials or light probes to save time. Pre-made materials are pre-configured materials that are optimized for certain types of surfaces, such as metal or wood. Light probes are pre-rendered images that can be used to simulate indirect lighting in the scene.

Use the “Simplify” modifier:

The “Simplify” feature in Blender allows you to reduce the complexity of the scene by adjusting settings such as the maximum number of faces, the maximum number of subdivisions, and the maximum number of shadow samples. By using the “Simplify” feature, you can speed up the rendering process without sacrificing too much detail. However, it’s important to be careful when using the “Simplify” feature, as it can also reduce the quality of the final rendering if you adjust the settings too aggressively.

Use proxies

Proxies are simplified versions of objects that can be used to speed up the rendering process. When you use a proxy, Blender will render the simplified version of the object instead of the full version. This can be especially useful for large or complex objects that may slow down the rendering process. To use proxies in Blender, you can use the “Make Proxy” feature in the “Object” menu.

Pre-render elements of the scene:

‍Pre-rendering is the process of rendering part of the scene in advance and saving the result as an image or video file. You can use pre-rendering to speed up the rendering process by rendering certain elements of the scene in advance and then compositing them together in the final rendering. For example, you can pre-render shadows, reflections, or other complex effects and then use them in the final rendering.

Use a render farm:

If your rendering times are still taking too long, you may want to consider using a render farm. A render farm is a network of computers that can be used to distribute the rendering workload across multiple machines. This can significantly speed up the rendering process, especially for large or complex projects. With renderjuice, you can easy setup and use our plugin to be able to use the Render Juice feature to submit your project to a render farm and track the progress of the rendering process. We’re quite proud of our technology and think it could vastly speed up your workflows.

Still too slow?

Overall, optimizing the 3D scene is a crucial step in speeding up rendering in Blender. By reducing the number of objects, materials, and lights in the scene, using simple setups, and utilizing features such as the “Simplify” tool and proxies, you can significantly improve the rendering speed of your project. If after applying some of these changes, your render is still taking too long, try using some of our other recommended approaches on configuring settings to continue to improve your render times. This is part three of a series in which we teach you how to improve your render times in Blender.