Why are some modders lying about parallax effect?

Understanding Parallax Mapping, Displacement Mapping, and Bump Mapping in Games

As a modder who values honesty and transparency, it deeply bothers me to see some creators misrepresent their work. I always strive to be truthful with our supporters, without hiding behind technical jargon or overstating our achievements. Unfortunately, we’ve observed a trend where more and more modders falsely claim to implement advanced parallax effects when they’ve only used simpler techniques like bump mapping.

This practice is particularly painful because it takes advantage of users who might not fully understand the technical details but are drawn to terms like “parallax”, believing it represents the pinnacle of graphical enhancement. These users often pay for mods under false pretenses, unaware that what they’re seeing isn’t true parallax mapping. This article aims to clear up the confusion, not only to educate gamers and mod enthusiasts but also to promote integrity within the modding community.

Table of Content

1. What Are Texturing Techniques?
2. Bump Mapping: The Basics
3. Parallax Mapping: Adding Depth to Flat Surfaces
4. Displacement Mapping: True Geometric Depth
5. Why Some Modders Mislead About Techniques
6. How to Tell the Difference as a User
7. Terminology Section
8. Conclusion

1. What Are Texturing Techniques?

In video games, creating realistic surfaces involves more than just applying flat images (textures) to 3D objects. Advanced techniques simulate depth, lighting, and surface detail to make textures look more lifelike. Among these techniques, parallax mapping, displacement mapping, and bump mapping are commonly used. While they might appear similar to the untrained eye, they work differently under the hood.

2. Bump Mapping: The Basics

Bump mapping is the simplest of the three techniques. It was introduced to gaming as a way to make textures look more detailed without adding more polygons (the building blocks of 3D models).

How It Works:

• Bump mapping manipulates the surface normals of a texture. Normals define how light interacts with a surface. By altering them, bump mapping creates the illusion of bumps and grooves.
• The underlying geometry remains flat — there are no actual physical deformations on the surface.

Advantages:

• Low performance cost.
• Suitable for small details like scratches or small cracks.

Limitations:

• Doesn’t change the silhouette of the object.
• Lacks realism when viewed from sharp angles.

Common Use Cases:

• Used for subtle surface details that don’t require realistic depth, such as leather textures or small dents.

3. Parallax Mapping: Adding Depth to Flat Surfaces

Parallax mapping takes surface detail simulation a step further. It creates the illusion of depth by adjusting texture coordinates based on the viewer’s perspective.

How It Works:

• A height map, which represents the surface’s elevations and depressions, is used.
• The game’s rendering engine shifts the texture coordinates based on the camera’s angle. This makes textures appear to have real depth as you move around them.

Parallax Occlusion Mapping (POM):

• A more advanced version of parallax mapping.
• Uses ray tracing within the texture to determine which parts should be visible, creating more realistic results.

Advantages:

• Provides realistic depth illusions without modifying geometry.
• Effective for surfaces viewed at an angle, like pavements, tiled floors, and brick walls.

Limitations:

• Performance cost is higher than bump mapping but lower than displacement mapping.
• The illusion breaks when viewed from extreme angles or up close.

Common Use Cases:

• Ideal for surfaces that need depth illusions without actual geometric detail, such as cobblestone streets or tiled roofs.

4. Displacement Mapping: True Geometric Depth

Displacement mapping is the most realistic method because it physically alters the 3D model’s geometry based on a height map.

How It Works:

• The surface’s mesh is subdivided into smaller polygons (using tessellation).
• Vertices of the mesh are displaced along their normals based on the height map.
• This creates real 3D depth, meaning the surface casts accurate shadows and interacts naturally with lighting.

Advantages:

• Produces unparalleled realism with true geometric deformation.
• Accurate lighting and shadow behavior.

Limitations:

• High performance cost, especially for detailed meshes.
• Requires more complex shaders and higher resolution meshes.

Common Use Cases:

• Close-up objects like rocks, tree bark, and terrain surfaces in highly detailed environments.

5. Why Some Modders Mislead About Techniques

Modders sometimes exaggerate the techniques used in their mods, claiming bump mapping or basic textures as “parallax effects” to make their work appear more advanced.

Misrepresentation:

• When a modder claims their texture mod has parallax mapping but only uses bump mapping, they’re overstating its depth illusion capabilities.
• Users might notice that the “depth” doesn’t change realistically with perspective or lighting, revealing the truth.

Why It Matters:

• Parallax and displacement mapping require more effort and skill to implement, while bump mapping is simpler and less resource-intensive.
• Misleading claims can set unrealistic expectations and undermine trust in the modding community

6. How to Tell the Difference as a User

Here are a few ways to distinguish these techniques while playing:

Look for Perspective Changes:

• Move the camera around the surface. If the depth illusion changes with the angle, it’s likely parallax mapping or displacement mapping.
• If the “bumps” stay static, it’s just bump mapping.

Check for Shadows and Lighting:

• Displacement mapping will cast real shadows and interact accurately with light.
• Parallax and bump mapping won’t cast accurate shadows, as they’re visual illusions.

Examine Silhouettes:

• Displacement mapping alters the actual geometry, so edges and silhouettes will look jagged or uneven.
• Parallax and bump mapping will have perfectly smooth silhouettes, betraying their flat geometry

Terminology Section

1. Tessellation

• Definition: Tessellation is a process in 3D graphics that subdivides a surface into smaller polygons to add more detail dynamically. This technique works in real-time during rendering, allowing developers to increase or decrease detail based on the viewer’s distance from an object.
• Use in Mapping: Tessellation is critical for displacement mapping, where the actual geometry is altered. It allows a flat surface to deform into a realistic shape, creating true 3D depth.
• GTA 5 Usage: Not supported natively. The presence of a tessellation setting can lead some players to assume that GTA 5 extensively uses it for advanced features like displacement mapping, but in reality tessellation in GTA 5 is limited to specific objects and terrains, improving the overall appearance of the game without significantly increasing the performance burden.

2. Bump Mapping Technique

• Definition: A grayscale texture map that manipulates an object’s surface normals to create the illusion of depth and bumps without altering the geometry.
• How It Works: Lighter areas of the map appear raised, and darker areas appear recessed, but the actual 3D model remains flat.
• Strengths: Lightweight and easy to use, with minimal performance impact.
• Limitations: Fails to produce realistic depth when viewed from the side.
• GTA 5 Usage: Supported. Used extensively for minor details like small dents and scratches on surfaces.

3. Normal Mapping Technique

• Definition: A more advanced version of bump mapping that uses RGB colors to define how light interacts with the surface at different angles.
• How It Works: Each color channel (Red, Green, Blue) encodes directional information about the surface’s orientation, allowing for more accurate light and shadow effects.
• Strengths: Provides a more detailed and realistic look than bump mapping.
• Limitations: Like bump maps, it doesn’t alter geometry or silhouette.
• GTA 5 Usage: Supported. Widely used for enhancing textures like fabric, metal, and skin.

4. Height Mapping Technique

• Definition: A grayscale image where pixel intensity represents height. Unlike bump and normal maps, it’s often used to create physical deformations in displacement mapping or parallax mapping.
• How It Works: Light areas are elevated, and dark areas are recessed.
• Strengths: Essential for displacement and parallax effects.
• Limitations: Requires additional processing to translate into geometric or visual effects.
• GTA 5 Usage: Limited support. Used in some modding setups but not heavily integrated into the base game.

5. Displacement Mapping Technique

• Definition: Uses a height map to physically move the vertices of a 3D model’s geometry, creating real depth and deformation.
• How It Works: The game engine subdivides the surface using tessellation and adjusts each vertex based on the height map.
• Strengths: Produces true 3D effects with accurate shadows and interactions.
• Limitations: Requires significant computational power and isn’t viable for all systems.
• GTA 5 Usage: Not supported natively. Advanced modding techniques attempt to mimic this effect, but it’s not part of the game’s default rendering engine.

5. Parallax Mapping Technique

• Definition: A shader-based technique that uses a height map to simulate depth by shifting texture coordinates.
• How It Works: The game calculates how the viewer’s angle affects the appearance of the surface, creating a pseudo-3D effect.
• Strengths: Good balance between realism and performance.
• Limitations: Doesn’t alter geometry or cast real shadows, and the illusion breaks at extreme angles.
• GTA 5 Usage: Not natively supported. However, some mods implement custom shaders to achieve parallax-like effects.

6. Parallax Occlusion Mapping (POM) Technique

• Definition: An advanced version of parallax mapping that uses ray tracing within the shader to determine visible parts of a texture, enhancing the depth illusion.
• Strengths: Provides better results than standard parallax mapping with less distortion at angles.
• Limitations: Higher performance cost than standard parallax mapping.
• GTA 5 Usage: Not supported. Modders who claim to add POM effects in GTA 5 often use workarounds or misrepresent simpler techniques like bump mapping.

Conclusion

Understanding the differences between bump mapping, parallax mapping, and displacement mapping not only helps you appreciate the artistry behind game graphics but also enables you to critically evaluate mods and enhancements. While bump mapping provides basic detail, parallax mapping offers a more immersive depth illusion, and displacement mapping delivers true geometric depth at a higher performance cost.

As a gamer or mod enthusiast, recognizing these distinctions can help you make informed decisions and avoid falling for exaggerated claims. The next time you see a “parallax-enhanced” mod, you’ll know exactly what to look for and whether the creator’s claims hold up.