illuminated_lines

Synopsis

Display of Illuminated Field Lines using texture mapped illumination model on polylines with line halo and animation effects.

Input Port

in_mesh

Mesh+Node_data

Polylines Mesh with optional node data

Parameters

Name	Type	Description	UI panel control
Ambient Diffuse Specular Phong Shininess Phone Modifier Line Opacity Color Blend	Double	Normal Lighting/Shading Model control parameters	UIsliders
Line Width Halo Width	int	Polylines and Halo width parameters	UIslider
Depth Mask Antialias Smooth Shading	int	Rendr mode toggle controls, to set various modes of display and line treatment	UItoggles
animationOn	int	Enables effect animation controls	UItoggle
Stair Dash Modulate Transparency Modulate Width	int	Selcts type of effect: Stair/ Dash Transparency/Width modulation	UIradioBoxes
StairType	int	Selection of Stair effect Up/Down/Up&Down	UIoptionMenu
Length Spacing	int	Parameters for effect (active number of segments for effect, followed by inactive 'spacing' segments)	UIsliders
inverse effect	int	Inverses the effect (inverts opacity/width values)	UItoggle
effectStep	int	Current loop time

Output Port

obj

GDobject

Directly renderable output object

Description

Introduction

Computer graphics techniques have long been used as an investigative tool for computational fluid dynamics (CFD). Many techniques are in common use, including vector arrow plots, contours, isosurfaces, cut planes, streamlines and particle animation. The main problem with 3D-flow visualization is the comprehension of the spatial structures of a flow field. The ability to view a real-time animated display of surface as well as flow-field information allows the investigator to rapidly pinpoint key areas of study.

Illuminated lines is method for using a dynamic texture map on 3D polylines to represent field streamlines for the purpose of visualizing continuous fluid dynamics fields. The method combines stream lines and particle animation into one hybrid technique, and employs texture display on lines to represent full 3D lighting, motion and 3D flow structure in one view. The technique exploits texture graphics systems in common use for games, and achieves high graphics efficiency during animation. In AVS/Express, Illuminated lines is implemented using a custom OpenGL render method. Thus the technique is only available when using the OpenGL renderer.

The input for illuminated lines must be a poly-line cell-set (unstructured) field such as produced by the MODS.streamline macro. This means that streamline must not be run in "ribbons" mode, because it puts out quad cells that illuminated_lines cannot use. There is no literal dependency between illumniated lines and streamline, although in practice, almost all real applications using illuminated_lines will also have a streamline ahead of illuminated_lines. DV_OGL.illuminated_lines has no field output, only a renderable GDobject output.

Prerequisites

This module requires OpenGL rendering to be active. Objects used in the construction of this system require the AVS/Express Developer Edition.

Data Types

This module requires the input mesh to contain one Polyline cell set. Any other type of cell set will be rejected, and any additional cell sets will be ignored. Any scalar node data may be present, or none for purely geometric display. Any special id node data (color, rgb, etc.) and any cell data is ignored.

Renderer Context

The implementation of the project is done by creating a custom render method that connects to the Graphics Display kit in AVS/Express. Any time the viewer refreshes or does a new scene update, it calls this custom method to perform the object draw. This method then contains the appropriate OpenGL calls to implement the illuminated line technique. If this module is used with another renderer, such as the software renderer or the "OutputImage" module, lines will be drawn in the default mode with illuminated line features turned off.

Input

Parameters

Enable Illumination Rendering

This toggles between illuminated line mode and standard line drawing methods.

Ambient

This value provides a base shadow value, a constant added to all shading values.

Diffuse

Pure diffuse reflection term, amount of shading dependent on light angle

Specular

Amount of specular reflection hi-lights based on light and viewer angle

Phong Shininess

Tightness of specular reflection, low values are dull, wide reflections, high values are small spot reflections.

Phong Modifier

Alters the width and shape of the diffuse component, controlling tightness of shading values.

Line Width

Controls line width. Normal 1-pixel lines are 1, can be increased in whole increments. Wide lines are drawn in 2D screen space, not full 3D ribbons. If you want full ribbons, use streamline module ribbon mode.

Line Opacity

Variable transparency of all lines. A value of 1.0 is fully opaque, while a value of zero makes lines invisible.

Color Blend

If node data is present, this controls the relative mix of data color and shading color. A value of zero sets full contribution of data color, while at 1.0 no data color is used and the line shade is dominated by illumination effects.

Depth Mask

This mode assists visual quality when transparency or antialiasing modes are used, helping to reduce artifacts caused by non-depth sorted line crossings.

Antialias

This effect, sometimes called "smooth lines" blends the drawing of lines to create a smooth effect, reducing the effects of "jaggies" at pixel resolution.

Smooth Shading

This enables an additional interpolation mode for blended node data colors. In the off state, data is sampled once per line segment. When enabled, linear interpolation is used between end points of each segment. This can be helpful if large gradients are present on low resolution polylines.

Halo Width

The width control for the halo effect defines the size of the transparent mask region added to the edge of each line. A value of zero turns off the halo effect.

Enable Animation Effect

This toggle controls the application of line segment variable modulation effects. When off, all lines are uniformly shaded and have constant width.

Stair / Dash

This choice selects the style of effect variation. Stair creates a linearly increasing or decreasing value, while step makes a binary chop effect.

Blend Mode

In stair mode, the blending can be selected to start small then get big, or the reverse or both. The values are down, up, up&down respectively.

Length

This slider sets the length of the effect along the polyline.

Spacing

This slider sets the spacing between effects along the line.

modulate transparency

In this mode the line segment varies in transparency from completely transparent to opaque.

modulate width

In this mode the line width is varied between 1 (very thin) to fat, based on the effect modes and shape controls.

Inverse Effect

As the animation effect is applied between two zones, such as the dash and the space between the dash, this toggle reverses the area where the effect is applied.

Animation Run

Run

This toggle enables the animation loop to run.

Cycle

If enabled, the animation loop continues forever in a cyclic fashion. If unset, the animation stops after once complete cycle. This is similar to the cycle parameter of the "Loop" module.

Reset Time

This is one-shot control to reset the animation to the start of a cycle

Output Port

Example

Libraries.Examples.Vizualization.IlineSpiralNoLight

v/dv_examp/il_spnl.v

Libraries.Examples.Vizualization.IlineSpiralHalo

v/dv_examp/il_sphalo.v

File

v/dv_ogl.v

See also related modules

Not applicable