Tequila

List of commands

Description

Tequila computes a UV texture image from a ply file, a set of images and their orientations. Ply file has to be a mesh, and can be the result of TiPunch (but not the direct result of C3DC).

Tequila performs six steps:

• load data
• compute zbuffers
• choose which image is best for each triangle
• filter mesh according to visibility
• write UV texture
• write ply file with uv texture coordinates

Choosing which image is best for each triangle can be done for the moment with two different criterions:

• best angle between triangle normal and image viewing direction (parameter Crit=Angle, by default)
• best stretching of triangle projection in image (parameter=Stretch)

For the angle criterion, expressed in degrees, a threshold is set to avoid using images that view a triangle with a low incidence (parameter Angle). It means that if the angle between triangle normal and image viewing direction is lower than Angle, the image will not be used for texturing.

Tequila has also two modes, which refer to texture computing strategies: basic and pack. In the basic mode, all images from the set are stored in the uv texture, and if necessary are downscaled. Each image is masked with the zbuffer, to store a minimum of significant information. In the pack mode, each image is divided in small regions, and only useful regions are packed into the uv texture, in an optimal way. This mode leads to smaller images, and gives better texture quality.

Relevant parameters are:

• Angle, threshold for minimum angle between normal and viewing direction (if Crit=Angle)
• Mode, choose between Basic and Pack (see upper)
• Crit, choose between Angle and Stretch (see upper)
• Scale, which allow to speed up computation (higher downscale factor leads to faster computation).
• Sz, which will force texture size, to conform with graphic card capacity (see GL MAX TEXTURE SIZE)
• QUAL, the jpeg compression quality, which allows to compact UV texture image.

Syntax

The global syntax for Tequila is :

mm3d Tequila FullName Orientationpath Plyfile

Help

You can access to the help by typing :

mm3d Tequila -help

Mandatory unnamed args :

• string :: {Full Name (Dir+Pat)}
• string :: {Orientation path}
• string :: {Ply file}

Named args :

• [Name=Out] string :: {Textured mesh name (def=plyName+ _textured.ply)}
• [Name=Bin] bool :: {Write binary ply (def=true)}
• [Name=Optim] bool :: {Graph-cut optimization (def=false)}
• [Name=Lambda] REAL :: {Lambda (def=0.01)}
• [Name=Iter] INT :: {Optimization iteration number (def=2)}
• [Name=Filter] bool :: {Remove border faces (def=false)}
• [Name=Texture] string :: {Texture name (def=plyName + _UVtexture.jpg)}
• [Name=Sz] INT :: {Texture max size (def=4096)}
• [Name=Scale] INT :: {Z-buffer downscale factor (def=2)}
• [Name=QUAL] INT :: {jpeg compression quality (def=70)}
• [Name=Angle] REAL :: {Threshold angle, in degree, between triangle normal and image viewing direction (def=90)}
• [Name=Mode] string :: {Mode (def = Pack)}
• [Name=Crit] string :: {Texture choosing criterion (def = Angle)}