Static 3D Triangle Mesh Compression Overview

3D triangle meshes are extremely used to model discrete surfaces, and almost always represented with two tables: one for geometry and another for connectivity. While the raw size of a triangle mesh is of around 200 bits per vertex, by coding cleverly (and separately) those two distinct kinds of information it is possible to achieve compression ratios of 15:1 or more. Different techniques must be used depending on whether single-rate vs. progressive bitstreams are sought; and, in the latter case, on whether or not hierarchically nested meshes are desirable during reconstructio

Multi-Resolution Texture Coding for Multi-Resolution 3D Meshes

We present an innovative system to encode and transmit textured multi-resolution 3D meshes in a progressive way, with no need to send several texture images, one for each mesh LOD (Level Of Detail). All texture LODs are created from the finest one (associated to the finest mesh), but can be re- constructed progressively from the coarsest thanks to refinement images calculated in the encoding process, and transmitted only if needed. This allows us to adjust the LOD/quality of both 3D mesh and texture according to the rendering power of the device that will display them, and to the network capacity. Additionally, we achieve big savings in data transmission by avoiding altogether texture coordinates, which are generated automatically thanks to an unwrapping system agreed upon by both encoder and decoder

ITEM: Inter-Texture Error Measurement for 3D Meshes

We introduce a simple and innovative method to compare any two texture maps, regardless of their sizes, aspect ratios, or even masks, as long as they are both meant to be mapped onto the same 3D mesh. Our system is based on a zero-distortion 3D mesh unwrapping technique which compares two new adapted texture atlases with the same mask but different texel colors, and whose every texel covers the same area in 3D. Once these adapted atlases are created, we measure their difference with ITEM-RMSE, a slightly modified version of the standard RMSE defined for images. ITEM-RMSE is more meaningful and reliable than RMSE because it only takes into account the texels inside the mask, since they are the only ones that will actually be used during rendering. Our method is not only very useful to compare the space efficiency of different texture atlas generation algorithms, but also to quantify texture loss in compression schemes for multi-resolution textured 3D meshes

El derecho ambiental y la participación ciudadana: hacia un vital punto de encuentro en México y el mundo

[RESUMEN] El derecho humano a un medio ambiente sano, precisa de una nueva conceptualización ala luz de la democracia participativa que le permita vincular los instrumentos del derecho ambientalcon las figuras de la participación ciudadana, para aspirar a la sustentabilidad y la protección delos derechos de las generaciones futuras; en virtud de que es imperativo que el ciudadano tomeconciencia de su deber ambiental ante las problemáticas ambientales que el accionar del ser humano,ha propiciado en el medio ambiente[ABSTRACT]The human right to a healthy environment needs a brand new conceptualization thattakes into account the advancements in participative democracy so it can link the instruments ofenvironmental law to mechanisms of citizen participation, to achieve the goals of sustainability andprotection of the rights of the future generations; in the understanding that it is imperative that thecitizen takes awareness of his environmental duty to the environmental issues that the actions of thehuman being have propitiated on the environmen

Colaboración con Centroamérica atiende grupos en vulnerabilidad

La propuesta se fundamenta en que el prefigurar acciones específicas de prevención hacia grupos altamente vulnerable por discapacitaciones físicas, considerando las características de las regiones en interacción con otros de alta marginación socio-econónomica, ha sido prácticamente soslayado

Evaluation of pulse detection of the Geostationary Lightning Mapper (GLM)

En aquest estudi s'evalua la sensibilitat del sistema GLM (Geostationary Lightning Mapper) davant els fotòmetres de MMIA (Modular Multispectral Imaging Array), en concret el fotòmetre 3 captant llum a 777.4nm de longitud d'ona. Per a fer-ho, les dades de GLM i MMIA son extrets dels fitxers amb informació preprocessada per LCFA (Lightning Cluster Filter Algorithm) -dades classificades per temps, geolocalització, intensitat de la detecció i amb un número identificatiu- per a posteriorment ser tractats mitjançant la classificació de les seves senyals en deteccions donades per la xarxa de detecció de rajos Linet a Colombia, sincronització de senyals i comparació de pics de senyal.En este estudio se evalúa la sensibilidad del sistema GLM (Geostationary Lightning Mapper) frente a la de los fotómetros de MMIA (Modular Multispectral Imaging Array), en concreto el fotómetro 3 captando la luz en 777.4 nm de longitud de onda. Para ello, tanto los datos de GLM como de MMIA son extraídos de los ficheros con información preprocesada por LCFA (Lightning Cluster Filter Algorithm) -datos clasificados por tiempo, geolocalización, intensidad de la detección y con un número identificativo- para posteriormente ser tratados mediante la clasificación sus señales en detecciones dadas por la red de detección de rayos Linet en Colombia, sincronización de señales y comparación de picos de señal.This study evaluates the sensitivity of the Geostationary Lightning Mapper (GLM) versus the Modular Multispectral Imaging Array (MMIA)'s photometer 3, both operating at the oxygen band at 777.4nm of wavelength. To do so, both GLM's and MMIA's data is extracted from pre-processed data files by a Lightning Cluster Filter Algorithm (LCFA) -data classified by time, geolocalization, detection intensity and with an ID number- to be treated by classification of their signals according to Linet Lightning Mapper Array (LMA) detections in Colombia, signal synchronization and peak comparison

3D facial merging for virtual human reconstruction

There is an increasing need of easy and affordable technologies to automatically generate virtual 3D models from their real counterparts. In particular, 3D human reconstruction has driven the creation of many clever techniques, most of them based on the visual hull (VH) concept. Such techniques do not require expensive hardware; however, they tend to yield 3D humanoids with realistic bodies but mediocre faces, since VH cannot handle concavities. On the other hand, structured light projectors allow to capture very accurate depth data, and thus to reconstruct realistic faces, but they are too expensive to use several of them. We have developed a technique to merge a VH-based 3D mesh of a reconstructed humanoid and the depth data of its face, captured by a single structured light projector. By combining the advantages of both systems in a simple setting, we are able to reconstruct realistic 3D human models with believable faces

COLLADA + MPEG-4 or X3D + MPEG-4

The paper is an overview of 3D graphics assets and applications standards.The authors analyzed the three main open standards dealing with three-dimensional (3-D) graphics content and applications, X3D, COLLADA, and MPEG4, to clarify the role of each with respect to the following criteria: ability to describe only the graphics assets in a synthetic 3-D scene or also its behavior as an application, compression capacities, and appropriateness for authoring, transmission, and publishing. COLLADA could become the interchange format for authoring tools; MPEG4 on top of it (as specified in MPEG-4 Part 25), the publishing format for graphics assets; and X3D, the standard for interactive applications, enriched by MPEG-4 compression in the case of online ones. The authors also mentioned that in order to build a mobile application, a developer has to consider different hardware configurations and performances, different operating systems, different screen sizes, and input controls

Domingo del Monte, ¿“El más real y útil de los cubanos de su tiempo”?

José Martí stated that Domingo del Monte was “the more real and useful of the Cubans of his time”. Scholars of Cuban culture have continued to use the phrase to affirm the role of del Monte in the gestation of the national consciousness. In discussing mainly the correspondence of del Monte with the U.S. diplomat Alexander Everett, this article demonstrates that, paradoxically, Marti judgment asserted a Cuban identity linked to racism and annexionism to the United States.José Martí llamó a Domingo del Monte “el más real y útil de los cubanos de su tiempo”. Los estudiosos de la cultura cubana no han dejado de usar la frase para afirmar el protagonismo de Del Monte en la gestación de la conciencia nacional. Al discutir principalmente la correspondencia de Del Monte con el diplomático norteamericano Alexander Everett, este artículo demuestra que, paradójicamente, el juicio martiano inscribió una cubanidad enlazada al racismo y al anexionismo