Blender’s volumetrics system offers incredible depth and realism, allowing artists to create stunning fog, smoke, clouds, and other volumetric effects. However, rendering volumetrics can often be tricky—especially when artifacts appear in the final render. Whether you’re working on a cinematic animation or a visual effects project, ensuring that your volumetric effects are clean and artifact-free is essential for achieving professional-quality renders.

Fortunately, rendering Blender volumetrics in the cloud offers a solution that bypasses some of the limitations of local hardware. In this post, we’ll discuss how to render volumetric effects in Blender without artifacts and how using a Blender Render Farm like 3S Cloud Render Farm can elevate your rendering process.

What Are Volumetrics in Blender?

Before diving into rendering techniques, let’s first define what volumetrics are. In Blender, volumetrics refer to the way light interacts with particles within a scene, creating effects like fog, smoke, fire, and clouds. These effects add depth, atmosphere, and realism, making them a powerful tool in visual storytelling.

However, rendering these effects comes with its own set of challenges. Volumetrics can be computationally expensive, especially in scenes with complex lighting and high-resolution simulations. This can lead to issues such as grainy or noisy renders, light leaks, and other visual artifacts.

Common Volumetric Rendering Issues

1. Noise and Grain
   The most common issue when rendering volumetrics is noise or graininess. This happens because of insufficient sampling, which causes inconsistencies in the light passing through the volumetric material.
2. Fireflies
   Fireflies are bright, isolated white pixels that can appear in scenes with high contrast, especially in volumetric effects like smoke or fire. These can be distracting and ruin the final output.
3. Light Leaks
   Light leaks occur when light passes through unintended gaps in volumetric materials, creating harsh, unrealistic edges or light streaks.
4. Low Resolution
   Another issue is the lack of resolution in the volumetric simulation, which can result in low-quality effects that appear blocky or pixelated.

How to Render Blender Volumetrics Without Artifacts

1. Increase Sampling for Volumetrics

The most effective way to reduce noise and grain in your volumetric renders is to increase the sampling rate. In Blender, volumetric effects use the Volume Scatter and Volume Absorption shaders. These shaders are sampled to calculate how light interacts with the material.

• In Cycles Render, increase the Samples under the Render Settings tab. A higher sample count results in less noise but also longer render times.
• In Eevee, adjust the Volumetric Samples and Volumetric Scattering settings for better light interaction and clarity.

However, increasing samples can significantly impact render times, especially when working with large, detailed scenes. This is where utilizing a Blender Render Farm like 3S Cloud Render Farm can be a game-changer. With cloud-based rendering, you can distribute the workload across multiple machines, ensuring faster rendering times without sacrificing quality.

2. Enable Denoising

To further reduce noise and grain, especially in low-sample renders, enabling denoising is an excellent technique. Blender provides built-in denoising options that can help clean up your renders.

• Cycles Render: Use the OptiX Denoiser or OpenImageDenoise to remove noise from the render after it’s complete.
• Eevee: Enable denoising under the Post Processing section in the Render settings.

Denoising can be particularly useful when rendering on a Blender Render Farm, as cloud rendering platforms like 3S Cloud can provide more robust denoising algorithms and faster compute resources.

3. Clamp the Lighting

One of the main causes of fireflies in volumetric renders is overexposed lighting. Clamping light intensities can prevent fireflies by limiting the maximum light contribution from any single light source.

• Clamp Direct and Indirect Lighting: In the Render Properties tab under the Sampling section, enable Clamp Direct and Clamp Indirect to reduce the chances of fireflies appearing in your renders.

This method helps keep the lighting more controlled and prevents the sharp, bright spots that can cause unwanted artifacts.

4. Use the Right Resolution for Volumetric Simulations

Low-resolution volumetric simulations are more likely to produce blocky, pixelated effects. Therefore, ensure that your simulations are set to a higher resolution for smooth results.

• Increase the Resolution Divisions in the Render Settings under the Volume section.
• Use Voxel Size settings to control the size of the grid used in your simulation. Smaller voxel sizes lead to more detailed effects but require more computational power.

When rendering high-resolution volumetric simulations, using a Blender Render Farm like 3S Cloud can handle the increased computational demand, speeding up the process significantly.

5. Optimize the Scene for Volumetrics

Ensure that your scene is optimized for volumetric rendering. Here are some tips for optimizing volumetric effects:

• Avoid Overlapping Volumes: Multiple overlapping volumetric materials can cause unintended artifacts. Instead, create separate volumes with proper spacing.
• Use Proper Light Setup: Make sure your light sources are appropriately placed to illuminate your volumetrics without causing harsh shadows or light leaks.

A well-optimized scene not only renders faster but also looks more polished, especially when processed through a Blender Render Farm.

>>> Read more: Grease Pencil in Blender: The Future of 2D/3D Hybrid Animation​

Why Choose 3S Cloud Render Farm for Volumetric Rendering?

Rendering complex volumetrics locally can be challenging due to the high demands on your computer’s hardware. A Blender Render Farm like 3S Cloud Render Farm provides several benefits for volumetric rendering:

• High-performance GPUs: With powerful GPUs dedicated to rendering, 3S Cloud Render Farm can handle the heavy computational load of volumetric effects, reducing render times significantly.
• Scalability: Need to render a large scene or animation with complex volumetrics? 3S Cloud Render Farm scales with your needs, ensuring faster turnarounds for large projects.
• Seamless Integration: 3S Cloud offers smooth integration with Blender, allowing you to upload and render your scenes quickly without additional hassle.

By offloading the heavy lifting to 3S Cloud Render Farm, you ensure that your volumetric effects are rendered at the highest quality, free of artifacts, and within the tightest deadlines.

Conclusion

Rendering volumetrics in Blender can be a challenging task, but with the right techniques and tools, you can produce stunning, artifact-free results. By increasing sampling, enabling denoising, clamping lighting, and using high-resolution simulations, you can significantly improve the quality of your volumetric renders.

For faster, more efficient rendering of complex volumetrics, consider using a Blender Render Farm like 3S Cloud Render Farm. With our powerful cloud infrastructure, you can ensure that your final render is not only free of artifacts but also produced on time.

Start your next project with 3S Cloud Render Farm today and experience seamless, high-quality volumetric rendering.