Rendering Techniques in Virtual Reality.pdf

This presentation is about Virtual Reality rendering techniques and algorithms. Some rendering algorithms in VR are discussed.

1. Rendering Techniques
in
Virtual Reality
Presented by-
88-CS-A-Aditya Bhendavadekar
89-CS-A-Gauri Kshirsagar
91-CS-A-Devansh Jaiswal
92-CS-A-Gauri Barge
Vishwakarma Institute Of Technology,Pune
Subject:

CGAVR

2. Introduction to Virtual Reality1.
Key Goals of VR Rendering2.
Fundamental Rendering Techniques3.
Technological Advancements4.
Basic Algorithms of Rendering5.
Challanges and Future Directions6.
Conclusion7.
References8.
Agenda

3. Introduction to VR
Definition of
Virtual Reality
Rendering is vital for
creating immersive
experiences in VR by
bringing virtual worlds
to life.
VR systems encompass
headsets, controllers,
and tracking systems for
user engagement.
VR is an interactive,
computer-generated
experience within a
simulated environment.
Rendering
Importance
Key Components
of VR

4. Key Goals of Rendering
1
Real Time Performance
Ensuring a seamless experience
without delays or lags for user
engagement.
2
Stereoscopic 3D
Creating depth and realism through
the perception of the 3D
environment.
3
Low Latency
Minimizing the delay between user
action and system response for
natural interactions.
4
Head-tracking &
Positional Tracking
Enabling accurate movement
tracking for a more immersive
experience.

5. Fundamental Rendering
Techniques in VR
Rasterization Ray Tracing
Converts 3D objects into
2D images for real-time
rendering with enhanced
speed.
Simulates how light
interacts with objects,
producing realistic
reflections and shadows
in VR.

6. Fundamental Rendering
Techniques in VR
Global Illumination Volumetric Rendering
Replicates complex
lighting effects, like
sunbeams and ambient
occlusion, for immersive
environments.
Creates 3D volumes for
fog, smoke, fire, and
other atmospheric
effects in VR scenarios.

7. Technological Advancements in
VR Rendering
Asynchronous
Timewarp
(ATW) &
Spacewarp
(ASW)
Minimizing motion
blur and judder for
smoother VR
experiences.
Concentrating
rendering power on
the user's focal point
for efficient
performance.
Dynamic
Lighting &
Environmental
Effects
Enhancing visual
realism with dynamic
lighting and
atmospheric effects.
Audio
Spatialization
Creating immersive
soundscapes to
match the visual VR
environment.
Foveated
Rendering

8. Ray tracing is a technique for rendering 3D graphics with very complex light
interactions.This means you can create pictures full of mirrors, transparent
surfaces and shadows with stunning results.
To recreate photo-realistic 3D images on a 2D computer screen.
Simulates light rays within a 3D environment.
Since light rays have predictable physical properties, the ray tracing algorithm
attempts to calculate the exact coloring of each ray-object intersection.
Ray tracing is revolutionary because it allows light rays to bounce from object
to object.
Ray Tracing
What is Ray Tracing?
Purpose of Ray Tracing

9. Ray Tracing Model
Fig 1. Ray tracing Model

10. Ray Tracing Algorithm
Scene Setup:
1. Define Scene Objects:
This involves specifying their positions, sizes, and orientations.
2. Set Camera and Viewport:
Define the camera position and orientation within the scene
3. Assign materials to objects in the scene:
Materials define how objects interact with light, including properties like
reflectivity, transparency, and color.
4. Lighting:
Set up light sources in the scene.(point light source, directional light (like
sunlight, or multiple light sources.)

11. Ray Casting:
5. Per-Pixel Processing:
For each pixel on the image plane (virtual screen):
Cast a primary ray from the camera position through the center of the pixel and
into the 3D scene.
6. Ray-Object Intersection:
Calculate the intersection(s) of the ray with objects in the scene.
7. Identify Closest Intersection:
Among all the intersections found, identify the closest intersection point to the
camera. This point contributes most to the pixel's final color.

12. Shading and Lighting:
8. Shading Calculations:
At the identified intersection point, perform shading calculations to determine
the final color of the pixel.
This considers factors like:
- Light source visibility
- Material properties at the intersection point
9. Recursion for Reflections (Optional):
For more realistic effects, ray tracing can be extended with recursion:
If the material at the intersection point is reflective, cast a new ray in the reflection
direction based on the incoming ray and surface normal.
Repeat steps 6-8 for this reflected ray to calculate its contribution to the pixel
color.

13. Image Formation:
10. Pixel Coloring:
Based on the shading calculations (and potentially reflections), set the
final color of the pixel in the image buffer.
Following these steps will guide you through the core process of
ray tracing an image.

14. Ray Tracing
Fig 2. Ray tracing effects

15. Challanges
Hardware
Limitations
Overcoming constraints
to achieve higher VR
rendering performance
and quality.
Photorealism
Goals
Striving to achieve lifelike
visual quality through
advanced rendering
techniques.
Foveated
Rendering
It is difficult to reduce
load by rendering only
center portion of user’s
field of view in detail.

16. Future Directions
Real-Time Ray
Tracing
hardware-accelerated ray
tracing for cinematic-
quality visuals in real-
time.
Machine
Learning and
AI:
AI-driven rendering
techniques improve VR
visuals by reducing
noise, enhancing details,
and accelerating
rendering.
Eye Tracking
Integration
enables efficient
rendering via techniques
like foveated rendering
and gaze-based depth-of-
field effects, enhancing
VR performance and
visual quality.

17. Immersion and
Innovation
Emphasizing the role of
rendering in fostering
immersive and innovative
VR experiences.
Future Exploration
Encouraging continual
exploration and
advancement in VR
rendering technology.
User-Centric
Experiences
Ensuring user comfort and
engagement through
cutting-edge rendering
approaches.
Conclusion

18. References
https://fortes.vision/blog/real-time-rendering/
https://blog.unity.com/news
https://developer.nvidia.com/discover/ray-
tracing#:~:text=Ray%20tracing%20generates%20computer%20
graphics,back%20to%20the%20light%20sources.
https://gfxcourses.stanford.edu/cs248/winter21content/media/v
r/12_vr_sm.pdf
https://www.canva.com/design/DAF9yQFyAek/cKliUKYmldzZQl
n9MbH5Iw/edit

19. Thank You