Q&A: How Capcom Brought Path Tracing to RE ENGINE Across PRAGMATA and Resident Evil Requiem

Capcom’s RE ENGINE team set out to bring path tracing into two shipping titles at once, Resident Evil Requiem and PRAGMATA, each with a different visual identity. 

Over two years, the RE ENGINE team built a reference path tracer, validated its lighting against common DCC path tracers, then scaled it into a game-oriented version optimized for DLSS and built on the NVIDIA RTX Kit. 

The payoff: direct lighting now runs through the path tracer instead of shadow maps, the visual gap between gameplay and cutscenes is greatly reduced, and strand hair picks up real-time light transmission in both titles. 

The NVIDIA gaming team spoke with RE ENGINE about the transition from ray tracing to full path tracing, what it changed in the content pipeline, and where the renderer goes next.

Why was now the time for Capcom to introduce path tracing into RE ENGINE in PRAGMATA and Resident Evil Requiem?

RE ENGINE has long invested in rendering technologies, including ray tracing, to create more immersive experiences. Titles such as Resident Evil Requiem and PRAGMATA increasingly rely on lighting to define the player experience through dark atmospheres, complex materials, and natural reflections.

Our game teams wanted indirect lighting and reflections to be integrated naturally across environments rather than adjusted individually. Advances in NVIDIA path tracing and frame generation technologies also made it realistic to bring rendering quality once limited to offline production into real-time games.

We also wanted to provide high-end PC users with experiences that can only be achieved on powerful hardware.

The introduction of path tracing is therefore the result of years of R&D, creative demands from game teams, the maturation of external technologies, and changing market conditions all aligning at the same time.

Seeing lighting naturally connect across entire scenes in development builds was particularly impactful. Reflections and indirect light, previously adjusted individually, began to form a cohesive space, giving us strong confidence that next-generation real-time lighting was finally clicking into place.

We have also continued to share knowledge and train teams beyond rendering engineers, including technical artists and artists. To use next-generation lighting technology effectively, the technology itself is not enough; the team also needs the production structure and expertise to integrate it into real game development. We see path tracing not merely as a visual upgrade, but as an important turning point in the evolution of real-time rendering.

How did you evolve from a ray tracing pipeline to a path tracing pipeline across multiple titles?

The teams worked together for two years to improve quality before the release of Resident Evil Requiem and PRAGMATA. We first developed a reference path tracer, then created a game-oriented path tracer optimized for DLSS Ray Reconstruction denoising. The reference path tracer was progressively refined by validating its detailed lighting behavior and bounce results against common DCC path tracers.

The game version was then scaled down to operate efficiently in real-time environments.

Technical artists also led the in-game integration, which allowed us to introduce the path tracer into both titles at the same time. When certain elements were difficult to support correctly, such as transparent lampshades built around blur filters, the teams quickly shared the issues and possible improvements with all stakeholders. This helped bring path tracing to a stable, usable state in the titles.

How does the path tracing implementation differ from previous ray tracing renderers?

Previously, ray tracing was used only for indirect lighting. In PRAGMATA and Resident Evil Requiem, it is also used for direct lighting. Character lighting in particular has improved significantly, creating more dimensional shadows and indirect illumination.

Traditional ray tracing relied on shadow maps, which often suffered from limited resolution. While this was less noticeable in cinematics due to manually tuned shadows, the lighting quality could feel compromised during gameplay. Because path tracing is active at all times, the visual gap between gameplay and cutscenes has been greatly reduced.

How did you ensure both ray tracing and path tracing could run across a wide range of devices?

The relatively contained environments featured heavily in Resident Evil Requiem and PRAGMATA worked to our advantage. Furthermore, our development environment, RE ENGINE, utilizes RayQuery-based ray tracing, allowing us to continuously validate ray tracing at any time. This established a strong foundation for running ray tracing across a wide range of devices.

Denoising is one of the key challenges of path tracing NVIDIA DLSS Ray Reconstruction provides faster and more stable denoising than hand-written shader-based solutions and serves as a critical foundation for our implementation.

We also had to optimize reflections and shadows for damaged areas with missing geometry. In the previous ray-tracing approach, which used shadow maps, AlphaTest did not create a special problem. With path tracing, however, producing soft shadows requires evaluating cutout areas in the shader when a ray hits. Performing texture lookups for AlphaTest at every ray hit would be too expensive, so we created a lightweight ScreenSpaceAlphaTest method that compares the ray-hit position against screen-space depth to determine whether the ray should pass through.

When using NVIDIA RTX Kit and DLSS 4, how do you manage sampling, noise, and denoising in complex scenes?

For emissive samples, using only the results of BSDF sampling causes contributions to accumulate only on hits, which creates a lot of noise. To address this, we use a dedicated sampling structure for Next Event Estimation (NEE). Additionally, to reduce noise in indoor areas where IBL is dominant, we utilize ReSTIR GI to sample contributing paths. Rather than using the implementation in RTX Kit, we reimplemented ReSTIR GI ourselves based on the published paper.

How did path tracing change the content pipeline, especially for materials and lighting in PRAGMATA‘s science fiction environments compared with the grounded realism of Resident Evil Requiem?

In both titles, path tracing improves global illumination and specular reflections, enabling higher-quality realization of each game’s artistic vision. For Resident Evil Requiem, because the title places strong emphasis on reproducing the real world, high-precision path-traced lighting greatly improves overall scene consistency and spatial believability. It also made asset quality and implementation issues easier to see, so we reviewed not only lighting, but also asset production, implementation rules, and quality verification. This allowed us to establish a development workflow focused on building quality throughout the entire content pipeline.

Path tracing also works well with strand hair; real-time light transmission through Grace’s hair contributed significantly to the sense of volume and material quality.

For PRAGMATA, path tracing is highly compatible with its hard-surface science-fiction environments, and high-quality reflections improve the title’s visual quality. Because surface precision, normals, and material settings affect the final image more directly, reflection-aware asset production and quality checks are more important, evolving the content pipeline so that quality is built in not only through lighting but from the asset-production stage onward.

PRAGMATA also uses strand hair: together with path-traced transmission, the title’s frequent three-dimensional movement and Diana’s long hair help make the action feel more dynamic. Realizing Diana’s long hair required overcoming hurdles such as hair count, joint count, and physical-control optimization, supported by knowledge accumulated from Resident Evil Requiem and cooperation between the RE ENGINE and PRAGMATA teams.

For both titles, it was also necessary to support not only path tracing, but also existing ray tracing and probe-based GI lighting.

What was the most significant visual improvement in Resident Evil Requiem when path tracing was enabled?

The sense of grounding. Properly depicting the points where objects rest on top of one another requires accurate shadows and indirect lighting results. Furthermore, character faces in particular are where these visual effects are most prominent. We have reached a level of quality that cannot be achieved without computing GI via path tracing. In addition, shadows created by indirect lighting give scenes a dimensional, grounded look that is unique to path tracing.

This level of visual quality would be difficult to achieve with traditional rasterization techniques.

Get started with NVIDIA RTX Kit

Check out  full path tracing  in Resident Evil Requiem and PRAGMATA. NVIDIA RTX Kit is the suite of neural rendering technologies behind this work, covering path tracing, geometry handling, and neural denoising. 

If you’re integrating path tracing into your own engine or title, get started with RTX Kit and explore the NVIDIA DLSS.

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