phg-vis 4.0.1

A package for the PHG modeling language and 3D visualization tool.

PHG

PHG (噬菌体) is a powerful 3D modeling and visualization library that combines a minimalist modeling language with Python integration. It provides procedural 3D scene generation, shader-based rendering, and specialized pipe system visualization.

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🌟 Features

• Minimalist Syntax - Declarative node tree description for 3D scenes
• Hierarchical Modeling - Support for nested nodes and transform inheritance
• Parametric Design - Flexible property system and function definitions
• Pipe Visualization - Specialized system for visualizing pipe structures with world/local coordinate support
• Shader Conversion - Convert PHG scripts to GLSL shaders for GPU rendering
• Dual Rendering Modes - Both real-time visualization (vis.exe) and offscreen rendering
• AI Parser Bridge - Use DGE++ PHG parser to normalize/enhance scripts before visualization
• Web Viewer - Export OBJ and view in a three.js browser viewer
• Python Integration - Comprehensive Python API for all features

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📦 Installation

pip install phg_vis

Or install from source:

pip install phg

Shader renderer dependencies (optional):

pip install phg_vis[shader]

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🚀 Quick Start

Python Usage

import phg

# Define PHG code
phg_code = """
{
    # Create a simple cylinder
    base{md:cylinder 5 10; rgb:100,150,200}
}setup_draw();
"""

# Execute PHG code
phg.run(phg_code)

Visualization Rendering

import phg

# Method 1: Direct rendering
phg.image("box(10);", filename="cube.png")

# Method 2: Complex scene rendering
scene = """
{
    base{md:cylinder 10 2; rgb:100,100,100}
    column{md:cylinder 5 20; y:2; rgb:200,200,200}
    top{md:cone 5 3 3; y:22; rgb:150,150,150}
    structure{[base,column,top]}
}setup_draw(structure);
"""
phg.image(scene, filename="tower.png")

# Method 3: Multi-view rendering
phg.image("sphere(5);|||view=2 width=1920 height=1080", filename="top_view.png")

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✨ Unified Visualization API

import phg

# Traditional vis.exe
phg.visualize("box(10);", mode="vis")

# Shader ray-march preview (GLSL)
phg.visualize("sphere(5);", mode="shader", width=800, height=600)

# Web (three.js) viewer
phg.visualize("box(10);", mode="web", out_html="view.html")

AI Parser Bridge (for improved PHG)

Use DGE++ PHG parser to normalize/enhance scripts before visualization:

import phg

phg.visualize(script, mode="vis", ai=True)
phg.visualize(script, mode="shader", ai=True)
phg.visualize(script, mode="web", ai=True, out_html="ai_view.html")

Environment override (optional):

set PHG_AI_ROOT=<PATH_TO_DGEPP_PHG_ROOT>

Web live server (serves HTML + OBJ):

phg.web_serve(script, host="127.0.0.1", port=8766, ai_root=None)

Notes for web viewer:

• Uses three.js CDN (requires network access)
• Uses AI bridge to export OBJ; ensure DGE++ is available
• Use web_serve to avoid file:// loader restrictions

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Script Syntax Essentials (PHG 3.0)

This section summarizes the most important script rules for stable rendering.

Mandatory Structure

{
    main_part{
        md:cylinder 5 20;
        xyz:0,0,0;
        rgb:180,180,220;
    }
}setup(); draw();

• Always use root braces { ... } to host scene nodes.
• Always finish with setup(); draw(); or setup_draw(node);.
• If setup/draw is missing, scene execution succeeds but no visible render is produced.

Node and Parameter Rules

• Node names should use English letters, digits, and underscore.
• For md: geometry parameters, use spaces: md:cylinder 5 10;.
• For vector attributes, use commas: xyz:1,2,3;.
• Avoid mixing comma-separated values into md: argument lists.

Composition Semantics

• Sequence <a,b,c> means parent-child chaining; transforms propagate along the chain.
• Array [a,b,c] means sibling nodes; they share parent context.
• Reusable templates are recommended for repeated parts to reduce duplicated attributes.

Primitive Origin Convention (Important)

• md:box w h d: origin p is the minimum corner, not center.
• md:cylinder r h: origin p is bottom-center, axis extends along local +Y.
• md:cone rb rt h: origin p is bottom-center, apex direction is local +Y.

To center-align box/cylinder/cone, add explicit offsets in node transforms.

Coordinate Convention

• Visualization side is typically left-handed with Y-up.
• Runtime coordinate switch in VIS affects display convention only; it does not change source modeling intent.

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Visualization Methods

Use one of these four methods depending on your workflow.

1) Desktop Interactive Viewer (vis)

import phg
script = "{ part{md:box 10 8 6; rgb:120,160,220;} }setup_draw(part);"
phg.visualize(script, mode="vis", ai=True)

• Best for interactive inspection, coordinate checks, and screenshots.
• Supports runtime coordinate convention switching.

2) Shader Preview (shader)

phg.visualize(script, mode="shader", ai=True, width=1024, height=768)

• Fast preview for basic geometry and transforms.
• Useful for lightweight render validation.

3) Web Viewer (web)

phg.visualize(script, mode="web", ai=True, out_html="scene_view.html")

• Generates browser-viewable result with OBJ pipeline.
• Prefer this for sharing and review.

4) Local HTTP Serving (web_serve)

phg.web_serve(script, host="127.0.0.1", port=8766, ai_root=None)

• Avoids file:// loading limitations in browsers.
• Recommended for stable three.js preview and OBJ loading.

5) 3D Scene Marking: Line / Arrow / Text

Use these markers to annotate dimensions, directions, and labels directly in the scene.

A. Line Markers (md:line / md:polyline)

{
    center_line{
        md:line 0,0,0 20,0,0 20,10,0;
        rgb:255,220,0;
        ts:2;
    }
}setup_draw(center_line);

• Syntax: md:line x1,y1,z1 x2,y2,z2 ...;
• Typical use: centerlines, route preview, measurement guides.

B. Arrow Markers (md:ptr)

{
    dir_x{ md:ptr 0.15, 1,0,0; xyz:0,0,0; rgb:255,80,80; }
    dir_y{ md:ptr 0.15, 0,1,0; xyz:0,0,0; rgb:80,255,80; }
    dir_z{ md:ptr 0.15, 0,0,1; xyz:0,0,0; rgb:80,120,255; }
}setup(); draw();

• Syntax: md:ptr radius, dx,dy,dz;
• dx,dy,dz is arrow direction vector.
• Typical use: nozzle orientation, local axis direction, flow direction.

C. Text Markers (md:text)

{
    tag_A{ md:text 'NOZZLE-A'; xyz:3,1,0; rgb:255,210,0; }
    tag_B{ md:text 'CHECK POINT'; xyz:8,2,1; rgb:180,220,255; }
}setup(); draw();

• Syntax: md:text 'your label';
• Typical use: part IDs, debug labels, warning notes.

D. Coordinate Frame Marker (md:C)

{
    frame_world{ md:C; xyz:0,0,0; }
    frame_local{ md:C; xyz:5,0,3; rz:30; }
}setup(); draw();

• Use md:C when validating axis orientation before checking geometry.

Coordinate Convention (Important)

• Default convention: Left-handed, Y-up.
• In default view: +X right, +Y up, +Z forward.
• Runtime coordinate switching in VIS changes display convention only, not the source modeling intent.

When exchanging data with other systems (e.g. Z-up pipelines), validate orientation with md:C + md:ptr first.

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📖 Syntax Reference

1. Basic Structure

{
    # Scene node definitions
    node definitions...
}setup();draw();  # or setup_draw();

Key Points:

• All nodes must be defined within the root node (anonymous braces)
• Call setup();draw(); or setup_draw() at the end for scene rendering
• Use # for single-line comments

2. Node Definition

2.1 Basic Syntax

nodeName{attributes and content}

2.2 Node Attributes

Attribute Type	Syntax	Description
Position	x:value y:value z:value	Single-axis position
Position (Combined)	xyz:x,y,z	Three-axis position
Rotation	rx:angle ry:angle rz:angle	Single-axis rotation (degrees)
Rotation (Combined)	rxyz:x,y,z	Three-axis rotation
Scale	s:scale	Uniform scaling
Color	rgb:red,green,blue	RGB color (0-255)
Tessellation	ts:subdivisions	Curve/surface subdivision level

Examples:

node1{x:10; y:20; z:30; rx:45; ry:90; rz:0}
node2{xyz:10,20,30; rxyz:45,90,0; s:2.0}
node3{rgb:255,128,0; ts:32}

2.3 Node Composition Methods

Sequence Composition (Transform Propagation):

parent{<child1,child2,child3>}

• Use angle brackets <> for sequences
• Parent node transforms are propagated sequentially to child nodes
• Commonly used for creating repetitive patterns (turbine blades, gear teeth)

Array Composition (Independent Transforms):

group{[item1,item2,item3]}

• Use square brackets [] for arrays
• Each child node maintains independent transforms
• Used for combining unrelated components

Comparison Example:

{
    # Sequence: Each box accumulates rotation
    gear1{<box1,box1,box1,box1>; rz:90}  # Four boxes at 0°, 90°, 180°, 270°

    # Array: Each box has independent transform
    gear2{[box1{rz:0},box1{rz:90},box1{rz:180},box1{rz:270}]}
}

2.4 Node Reference and Reuse

# Define template node
template{md:cylinder 10 20}

# Reference node
instance1{template; x:10}              # Inherit template and add translation
instance2{{template; s:0.5}; y:20}    # Scale first, then translate

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3. Model Definition (md Command)

3.1 Basic Syntax

{md:commandName param1 param2 ...}

3.2 2D Shapes

Command	Syntax	Description
Rectangle	md:rect width height	Rectangle
Circle	md:circle radius	Circle
Ellipse	md:ellipse2d majorAxis minorAxis	Ellipse
Polygon	md:poly x1,y1,z1 x2,y2,z2 ...	Arbitrary polygon

Examples:

rect1{md:rect 10 20}
circle1{md:circle 5; ts:64}               # 64 subdivisions
triangle{md:poly 0,0,0 10,0,0 5,10,0}

3.3 3D Primitives

Command	Syntax	Description
Cylinder	md:cylinder radius height	Cylinder
Cone	md:cone bottomRadius topRadius height	Cone/Frustum
Spherical Crown	md:sphericalcrown radiusX radiusY radiusZ	Spherical cap/hemisphere
Box	md:box length width height	Box

Examples:

cylinder1{md:cylinder 5 10}
cone1{md:cone 5 2 8}
hemisphere{md:sphericalcrown 3 3 1.5}
box1{md:box 10 5 2}

3.4 Curve Commands

Interpolated Curves:

{md:ccurve interpolationType startNode endNode}

Interpolation Types:

• lerpTX - Linear interpolation (tangent X direction)
• lerpTY - Linear interpolation (tangent Y direction)
• lerpTZ - Linear interpolation (tangent Z direction)
• lerp - Standard linear interpolation

Example:

{
    p1{} p2{x:10; rz:15}
    curve1{md:ccurve lerpTX p1 p2}
}

3.5 Surface Commands

Patch:

{md:face interpolationType curve1 curve2}

Extrusion:

{md:extrudex profile xStart yStart length}

Loft:

{md:loft profile1 profile2 path parameters}

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4. Data Structures

4.1 Location Data (Locations)

{md:Locations;
list:"
1
    1 0 0  # x coordinate
    0 1 0  # y coordinate
    0 0 1  # z coordinate
"
}

4.2 Curve Data (Curves)

{md:Curves;
list:"
    type param1 param2 param3 dirX dirY dirZ
"
}

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5. Control Statements

5.1 Conditional Statement

?(condition) { statement } : { else_statement };

5.2 Loop Statement

@n { statement1 ? (_i = x) ~; statement2; }

5.3 Function Definition

$functionName(args...) { statement; $return }

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6. Scene Rendering Functions

setup();draw();                  # Setup and draw entire scene
setup_draw();                    # Combined call
setup_draw(node1);               # Draw specified node
setup_draw(node1,node2,...);     # Draw multiple specified nodes

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🎨 Visualization Features

1. Interactive Screenshot (UI Button)

Click the Shot button in the 3D view interface to take a screenshot.

Features:

• One-click operation with auto-generated timestamped filename
• Default save location: Desktop as screenshot_YYYYMMDD_HHMMSS.png
• Real-time notification of screenshot results

2. Python API Rendering (Recommended)

import phg

# Default screenshot (shot.png)
phg.image("box(10);")

# Specify filename
phg.image("box(10);", filename="cube_render.png")

# Full path
phg.image("box(10);", filename="C:/output/result.png")

# Advanced: Custom resolution and view
phg_code = "box(10);"
phg.image(phg_code + "|||width=1920 height=1080 view=2")

3. HTTP API

Save to File:

POST http://127.0.0.1:5088/phg_img
Content-Type: text/plain

box(10);|||file=output.png width=1920 height=1080 view=0

Return Binary Data:

POST http://127.0.0.1:5088/phg_img
Content-Type: text/plain

box(10);|||width=800 height=600

4. Rendering Parameters

Request Body Format:

<PHG_CODE>|||<PARAMETERS>

Available Parameters:

Parameter	Type	Default	Description
file	string	-	Output filename, omit for binary return
width	int	1288	Render width (pixels)
height	int	800	Render height (pixels)
view	int	3	View mode (see table below)
quality	string	high	Render quality: high/low

View Modes:

Value	Mode	Description
0	Front	Front view (orthographic projection)
1	Right	Right view (orthographic projection)
2	Top	Top view (orthographic projection)
3	Perspective	Perspective view (default)

5. Batch Rendering Example

import phg

# Batch generate different views
views = [(0,"front"), (1,"right"), (2,"top"), (3,"perspective")]
phg_code = "box(10);"

for view_id, view_name in views:
    phg.image(
        f"{phg_code}|||view={view_id}",
        filename=f"cube_{view_name}.png"
    )

# Batch render different sizes
for size in [5, 10, 15, 20]:
    phg.image(f"box({size});", filename=f"box_{size}.png")

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🔧 Pipe Visualization System

PHG includes a specialized pipe visualization system for creating 3D pipe structures from simple string commands.

Pipe String Commands

• F - Forward (move forward in current direction)
• B - Back (move backward in current direction)
• R - Right (turn right and move)
• L - Left (turn left and move)
• U - Up (turn up and move)
• D - Down (turn down and move)

World Coordinate System

World coordinate pipes use absolute directions regardless of current orientation:

import phg
from coordinate_system import vec3, quat, coord3

# Create a pipe in world coordinates
# F moves along world Z+, R moves along world X+, etc.
start_pos = coord3(vec3(0, 0, 0), quat(1, 0, 0, 0))
phg_script = phg.world_pipestr_vis("FFRRUD", start_pos)

# Custom pipe appearance
phg.world_pipestr_vis(
    "FFLLUU",
    start_pos,
    pipe_color=(255, 100, 50),  # Orange pipe
    pipe_radius=0.5               # Thicker pipe
)

Local Coordinate System

Local coordinate pipes use directions relative to current orientation:

import phg
from coordinate_system import vec3, quat, coord3

# Create a pipe in local coordinates
# F moves forward relative to current orientation
start_pos = coord3(vec3(0, 0, 0), quat(1, 0, 0, 0))
phg_script = phg.local_pipestr_vis("FFRRUD", start_pos)

# The same string produces different results in local vs world coordinates
phg.local_pipestr_vis(
    "FFRRFF",  # Forward, Forward, Right turn, Right turn, Forward, Forward
    start_pos,
    pipe_color=(0, 255, 100)  # Green pipe
)

Direct PHG Script Generation

For advanced use cases, you can generate PHG scripts without immediate visualization:

import phg
from coordinate_system import vec3, quat, coord3

start = coord3(vec3(5, 0, 0), quat(1, 0, 0, 0))

# Generate PHG script for world coordinates
world_phg = phg.world_pipe_to_phg("FFRUD", start)

# Generate PHG script for local coordinates
local_phg = phg.local_pipe_to_phg("FFRUD", start)

# Visualize later
phg.vis(world_phg)

Example: Complex Pipe System

import phg
from coordinate_system import vec3, quat, coord3

# Create a complex pipe network
def create_pipe_network():
    # Main pipeline
    main_pipe = phg.world_pipestr_vis(
        "FFFFRRFFRRUUFFLLFF",
        coord3(vec3(0, 0, 0), quat(1, 0, 0, 0)),
        pipe_color=(100, 100, 255),
        pipe_radius=0.5
    )

    # Branch 1
    branch1 = phg.world_pipestr_vis(
        "RRUUFFFF",
        coord3(vec3(4, 0, 0), quat(1, 0, 0, 0)),
        pipe_color=(255, 100, 100),
        pipe_radius=0.3
    )

    # Branch 2
    branch2 = phg.local_pipestr_vis(
        "FFLLDDFF",
        coord3(vec3(8, 2, 2), quat(1, 0, 0, 0)),
        pipe_color=(100, 255, 100),
        pipe_radius=0.3
    )

    return main_pipe, branch1, branch2

# Create and visualize the network
pipes = create_pipe_network()

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💡 Complete Examples

Example 1: Simple Geometry

{
    # Create a cylinder with base
    base{md:cylinder 10 2; rgb:100,100,100}
    column{md:cylinder 5 20; y:2; rgb:200,200,200}
    top{md:cone 5 3 3; y:22; rgb:150,150,150}

    structure{[base,column,top]}
}setup_draw(structure);

Example 2: Parametric Gear

{
    # Create gear tooth
    tooth{md:box 2 5 3; z:10}

    # Create gear by rotating around center (8 teeth)
    gear{
        <tooth,tooth,tooth,tooth,tooth,tooth,tooth,tooth>
        rz:45  # Each tooth automatically rotates 45° (360/8)
    }

    # Center shaft
    shaft{md:cylinder 3 10; rgb:50,50,50}

    # Assembly
    assembly{[gear,shaft]; rx:90}
}setup_draw(assembly);

Example 3: Turbine Blade (Complex Assembly)

{
    # Define control points
    p1{}
    p2{x:4; rz:15}
    p3{x:4; rz:-15}

    # Create curves
    c1{{md:ccurve lerpTX p1 p2}{md:ccurve lerpTX p1 p3}}
    c2{c1; z:14; rz:75; s:0.75}

    # Create blade surface
    blade{{md:face lerp c1 c2; z:2; rz:90}ry:15}

    # Create impeller (24 blades)
    wheel{<blade,blade,blade,blade,blade,blade,blade,blade,
           blade,blade,blade,blade,blade,blade,blade,blade,
           blade,blade,blade,blade,blade,blade,blade,blade>}

    # Hub
    hub{md:cylinder 8 5; rgb:80,80,80}

    # Assembly
    turbine{[wheel,hub]}
}setup_draw(turbine);

Example 4: Python Rendering Workflow

import phg

# Define complex scene
scene = """
{
    # Ground
    ground{md:cylinder 20 0.5; rgb:80,80,80}

    # Main structure
    base{md:cylinder 5 2; y:0.5; rgb:150,150,150}
    column{md:cylinder 2 10; y:3.5; rgb:200,200,200}
    top{md:cone 3 0 2; y:9; rgb:180,180,180}

    # Decoration
    ring1{md:cylinder 4 0.3; y:5; rgb:255,200,0}
    ring2{md:cylinder 4 0.3; y:7; rgb:255,200,0}

    # Assembly
    monument{[ground,base,column,top,ring1,ring2]}
}setup_draw(monument);
"""

# Render multiple views
phg.image(scene + "|||view=3", filename="monument_perspective.png")
phg.image(scene + "|||view=0", filename="monument_front.png")
phg.image(scene + "|||view=2 width=2560 height=1440", filename="monument_top_4k.png")

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🎯 Best Practices

1. Naming Conventions

• Use meaningful node names
• Use lowercase letters and underscores
• Avoid using PHG keywords as node names

2. Structure Organization

• Group related nodes together
• Use comments to explain complex structures
• Use node references to reduce repetition

3. Performance Optimization

• Set appropriate tessellation levels (ts parameter)
• Reuse node definitions instead of recreating
• Use sequence and array composition appropriately

4. Debugging Tips

• Build complex models incrementally
• Use setup_draw(nodeName) to test nodes individually
• Check coordinate system and transform order

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📚 Built-in Functions

Math Functions

• rnd() - Random number
• sin() - Sine
• cos() - Cosine

Node Operations

• im() - Image operations
• on() - Enable node
• wak() - Wake node
• dump() - Dump node data

Data Conversion

• tojson() - Convert to JSON format

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🔧 Coordinate System

Coordinate System

• Uses right-hand coordinate system
• X-axis: Right
• Y-axis: Up
• Z-axis: Forward

Rotation Rules

• Rotation angle unit is degrees
• Positive rotation follows right-hand rule

Transform Order

• Transform order: Scale → Rotation → Translation
• Child node transforms are applied on top of parent transforms

---

❓ FAQ

Q1: What's the difference between sequences and arrays?

• Sequence <a,b,c> equals {a {b {c}}} - Transforms accumulate
• Array [a,b,c] equals {{a}{b}{c}} - Transforms are independent

Q2: How to create repetitive structures?

Use sequence composition <> with rotation:

# Create 8 evenly distributed elements
element{md:box 2 2 2; z:10; rz:45}
ring{<element,element,element,element,element,element,element,element>}

Q3: How to set transparent background?

Currently the rendering engine uses RGB format and doesn't support transparent backgrounds. For transparency, remove the background color in post-processing.

Q4: Is there a resolution limit for rendering?

Recommended maximum resolution is 4096 x 4096. Excessively large resolutions may cause insufficient GPU memory or rendering failures.

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🔗 Links

• PyPI Package
• Mathematical Foundation

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📄 License

This project is licensed under the MIT License.

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🙏 Acknowledgments

PHG is inspired by concepts from group theory, aiming to provide a flexible way to describe complex data structures in programming. Special thanks to all developers who have contributed to the PHG ecosystem.

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🤝 Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

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© 2025 PHG - Minimalist 3D Modeling Language