Vertex Shader Interpolation for Digital Map Style Rendering

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Solution Overview

Problem

Existing digital map rendering technologies face challenges in smoothly scaling road features across zoom levels due to the lack of style information for intermediate zoom levels, leading to abrupt transitions and poor rendering performance.

Innovation Solution

A software module interpolates style parameters for unavailable zoom levels by encoding style information into vertex attributes or textures, allowing for smooth scaling of road features and graphics elements, such as arrows, by arranging multiple instances along paths and adjusting their visibility based on zoom level.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If style information is provided only at discrete zoom levels, then bandwidth is conserved and server load is reduced, but abrupt transitions and popping occur between zoom levels

Engineering Contradiction:

Improvebandwidth consumptionVSAvoidrendering smoothness

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The system pre-provides style information at discrete zoom levels (N and N+2) during map data generation, enabling the client to perform linear interpolation for intermediate zoom levels (N+1) without requiring server computation at every possible zoom level. This preliminary preparation resolves the contradiction by providing sufficient data upfront for smooth rendering while maintaining server efficiency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Linear interpolation acts as an intermediary mechanism between discrete style definitions at zoom level N and N+2, generating smooth transitions for intermediate zoom levels. This mathematical intermediary allows the system to avoid providing style data for every zoom level while still achieving continuous visual transitions, resolving the bandwidth-smoothness tradeoff.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If style parameters are estimated at intermediate zoom levels, then continuous zoom display is enabled, but rendering accuracy decreases and transitions become abrupt

Engineering Contradiction:

Improvezoom level continuityVSAvoidstyle parameter accuracy

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The system changes the parameters provided to the client device from discrete, fixed values to interpolated values that continuously adapt to the current zoom level. By providing style parameters for multiple discrete zoom levels and enabling linear interpolation, the system achieves continuous adaptation to any zoom level while maintaining parameter accuracy through mathematical interpolation rather than rough estimation.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If arrows and graphics elements are rearranged to fill gaps during zooming, then visual continuity is improved, but rendering complexity and processing time increase

Engineering Contradiction:

Improvevisual continuityVSAvoidrendering complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Instead of dynamically rearranging and regenerating arrow graphics during zooming operations, the system creates multiple copies of arrow instances at predetermined positions along the road. These copies are pre-positioned to account for expected zoom levels, allowing the rendering system to simply select and display appropriate copies based on current zoom level without complex real-time calculations or rearrangements.

Inventive Principle:

Principle #26Copying

4Manufacturing precision

If multiple arrow instances are displayed at high zoom levels, then visual detail is improved, but data quantity and processing load increase at lower zoom levels

Engineering Contradiction:

Improvevisual detailVSAvoiddata quantity

Core Design Contradiction:

Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The system applies local quality by displaying different numbers of arrow instances based on the local zoom level context. At high zoom levels where more detail is needed and the visible road segment is shorter, multiple arrow instances are displayed. At lower zoom levels where less detail is needed and more road is visible, fewer arrow instances are displayed. This local adaptation optimizes both visual detail and data quantity dynamically based on display requirements.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS9542724B1Systems and methods for stroke rendering on digital maps

Publication Date: 2017.01.10 GOOGLE LLC

AI summary

To provide smoothly scaleable map features on interactive digital maps, a first and a second sets of style parameters for rendering a map feature at a first zoom level and a second zoom level, respectively, are received. The first and second sets of style parameters are provided to a vertex shader. The vertex shader is configured to interpolate the first set of style parameters and the second set of style parameters to generate an interpolated set of style parameters for a certain zoom level between the first zoom level and the second zoom level, and render the map feature at the certain zoom level in accordance with the interpolated set of style parameters.