Introduction
Real-time cinematic rendering refers to the ability to render high-quality 3D graphics and visual effects in real-time, at the same frame rates used for film and television. This allows content creators to see their final rendered output as they work, without having to wait for renders to complete.
In recent years, real-time rendering technology has advanced rapidly, bringing it much closer to the “Hollywood standard” of offline rendering used for major motion pictures and VFX. However, there are still limitations and challenges to overcome before real-time can fully match offline rendering in all aspects.
In this article, I will provide an in-depth look at the current state of real-time cinematic rendering and how close it is to the Hollywood standard in different areas like visual fidelity, workflow, and production capabilities. I will also discuss the remaining challenges and how developers are working to bridge the gap.
Visual Fidelity
Current Capabilities
The visual fidelity of real-time cinematic rendering has improved enormously thanks to advances in game engine technology like Unreal Engine and Unity, as well as dedicated real-time rendering engines.
With techniques like physically-based rendering (PBR), ray tracing, volumetrics, and high-resolution scanning and texturing, real-time cinematic rendering can now produce stunning, photoreal visuals that come very close to offline CGI for many shots. Real-time renders can match offline in areas like:
- Materials, surfaces, and textures
- Lighting and shadows
- Many environmental and atmospheric effects
This allows for very realistic looking characters, objects, and environments. Certain effects like smoke, fire, water, and debris are still better in offline rendering, but the gap has narrowed significantly.
Remaining Challenges
However, real-time rendering still faces challenges matching offline rendering in certain areas like:
- Geometry detail – offline can handle more complex and dense geometry.
- Shaders and materials – offline renderers like Arnold have more advanced shaders and materials.
- Lighting complexity – offline can simulate extremely complex lighting environments.
- Effects animation – offline can animate nuanced, detailed effects like cloth, hair, and fluids.
So for extremely complex scenes with things like huge crowds or tons ofSimulating natural phenomena like smoke, fire, and water at cinematic quality in real-time is still difficult. As are lifelike human characters that can emote convincingly.
Closing the Gap
Game engines continue to improve their material systems, geometry handling, and physical simulation capabilities with each new release. And real-time focused render engines like Unreal’s Lumen and Unity’s Enlighten are incorporating more cinematic features as well.
With cloud compute and improved algorithms, real-time rendering can leverage more resources to handle greater scene complexity that approaches Hollywood levels. AI and machine learning also show promise for filling the gaps in areas like animation and effects.
Most experts agree real-time rendering will match offline Hollywood CGI for many shots within the next 5-10 years if current trends continue. But it may take longer to simulate truly convincing human characters and extremely nuanced effects and animations.
Workflow
Current Capabilities
Using real-time game engines and interactive rendering, content creators can now work in a WYSIWYG (what you see is what you get) environment instead of having to imagine the final result while working and wait for test renders.
This enables:
- Instant feedback on creative choices
- Faster iteration and changes
- Reduced reliance on technical art and coding skills
With virtual production tools like LED walls, in-camera VFX, and motion capture, real-time environments can even be used live on set, with final pixel visuals in-camera. This brings many advantages:
- More creative freedom and spontaneity
- Cost savings compared to shooting on green screens
- More realistic lighting and reactions from actors
So in terms of creative workflow, real-time rendering can already provide many benefits over traditional offline workflows. Though offline workflows are still better suited for complex effects-heavy shots.
Remaining Challenges
However, real-time rendering introduces new workflow challenges including:
- More hardware dependencies
- Added complexity for collaboration and asset sharing
- Lack of existing pipelines for virtual production
- Limitations for making changes and tweaks after principal photography
These present obstacles for adopting real-time into larger productions with many collaborators. Solving these workflow hurdles is key for more widespread real-time cinematic adoption.
Transitioning Workflows
Dedicated solutions from companies like Framestore, Magnopus, and ARRI are helping tackle these challenges by building tailored real-time pipelines, collaboration tools, and onset workflow systems.
Many major studios are also forming specialized real-time focused divisions, training artists in Unreal and Unity workflows, and figuring out how to best incorporate real-time with their existing offline workflows.
So while real-time has some workflow challenges to overcome, many production houses are actively transitioning to hybrid pipelines that can leverage the strengths of both real-time and offline rendering. Most experts predict this hybrid approach will become the standard Hollywood workflow in the coming years.
Production Capabilities
Current Capabilities
Real-time rendering is already being used in production in areas like:
- Previs and storyboarding
- On-set visualizations
- Postvis and early shot exploration
This allows filmmakers to explore shots and sequences earlier, providing more flexibility in the edit.
For final pixels, real-time has been used successfully for things like:
- Backdrops and set extensions
- Static/minimal environments
- FX like fire, smoke, muzzle flashes
- Vehicles and mechanical objects
So it can already handle many simpler assets and effects at final production quality.
Remaining Challenges
However, for more central hero elements like characters, creatures, and environments, real-time rendering still faces limitations in capability and artistry compared to offline CGI. As well as constraints for complex camera animation, effects, and composition.
This makes it challenging for real-time to carry full sequences or shots on major hero elements that require the highest level of visual fidelity right now. Most studios still prefer offline rendering for these critical elements that drive storytelling and emotion.
Expanding Production Uses
But developers are actively working to expand real-time’s production capabilities for more central frame elements. For example, virtual humans and creatures are rapidly improving in quality and realism.
As real-time visuals continue approaching offline quality, its production use will dramatically expand, likely first taking over the majority of secondary visual elements.
Many experts predict within 5 years real-time CG will be able to carry full sequences and even replace offline rendering entirely for certain productions like lower budget films and real-time only projects.
Conclusion
In summary, real-time cinematic rendering still has some gaps to close, but has come extremely close to offline CGI quality for many types of shots, visual elements, and sequences.
It provides great advantages for creative iteration and on-set visualizations, though complex effects and final hero elements still benefit from offline rendering in many cases. Real-time workflows are evolving quickly as more studios transition to hybrid pipelines.
With steady advances in visual fidelity, workflow tools, and production capabilities – real-time rendering is poised to take on an increasingly central role in Hollywood production. Within the next decade, it has the potential to disrupt traditional workflows and emerge as a viable replacement to offline rendering across the board.
The future is bright for real-time rendering to finally fulfill its promise of providing real-time cinematic quality visuals to unlock new creative possibilities. But there are still challenges to solve before it can reliably match or exceed the Hollywood gold standard across all measures.
