Introduction:
This article was sent and accepted as one of the top ten full papers for SBGAMES 2010.
Fast Polygonization and Texture Map Extraction From Volumetric Objects explains the 3D Modelizer feature that is being developped for the beta versions of Voxel Section Editor III.
The Brazilian Symposium on Computer Games and Digital Entertainment is the most important brazilian symposium in game development and research, covering several areas from computer graphics to artificial inteligence, storytelling research, among other topics. It is the second biggest computer science conference in Brazil, only behind SBC's main event. (Note: SBC is the Brazilian Computing Society, a sort of equivalent organization to ACM, but in Brazil).
All articles must be written in english, however, at the event we were allowed to present them in portuguese, since most of the people who were in the conference are brazilians.
The motivation behind using Voxels for modelling purposes came from Project Perfect Mod Voxels forum.
How come people post much more voxels than 3D models in our forums? While it is notorious that PPM started with Tiberian Sun and the amount of modders who mod both Tiberian Sun and Red Alert 2 here still bypass the amount of those who work with the 3D SAGE engine used in Command & Conquer Renegade and newer games, we've noticed that even outside PPM, the number of artists who are able to create properly textured models for these newer games are very limited. The reason is very simple: in order to create complete 3D graphics used by these games, artists need to master extensive computer graphics concepts, including maths... and perhaps some physics as well. The existing conventional tools are not intuitive for the manipulation of textures: splitting the model in UV space is not a trivial task; users are not able to see where in the model they are painting, when they paint textures using Photoshop and other tools like that; normal maps shows colours instead of directional vectors; specular map is hard to understand; etc. There are tools like ZBrush that simplifies part of this process by allowing users to paint directly in the model, but they are expensive and they are still based in texture.
In this work, we understand that the use of textures is an artifact to optimize the use of the 3D model in the video card and it shouldn't be a duty from the artist to do that. Artists should express their ideas by modelling the shape and painting with voxels instead, just like what Voxel Section Editor III does, although we understand that VXLSE III is not the ideal program to create 3D models for newer games, since it has been created with the limitations of Red Alert 2 engine in mind since the beggining: limiting colour palette, normals and how it deals with skeleton hierarchy and animations.
This full paper explains how to make this process viable in a future 3D modelling program and providing the results in interactive time. It explains how the program should transform a model based on voxels in a 3D polygonal model with textures, by generating an initial mesh and manipulating the attributes of each vertex to make it look more smoothed, keeping the details added by the user. And it also shows how to generate a texture atlas that covers every face of the model automatically. The article does not get in details how to optimize the 3D mesh that it generates reducing the amount of polygons that it holds.
The method explained in this article has a couple of limitations that will be worked in the future. It may generate wrong results in the sections of the model that have a couple of topological problems, such as voxels whose neighbors are only linked by vertexes or edges, although it deals correctly with all other topoligical problems. Also, the texture atlas extraction technique is a bit naive and it may generate far too many partitions, decreasing the quality of the texture and the efficience of a future mesh optimization technique.
Abstract:
This work proposes a new method for the polygonization and texture map extraction from volumetric objects based on a polyhedral surface extraction and surface fairing approach. The surface faring approach is based on a mesh signal processing technique that uses an approximation of an adaptive low-pass filtering based on a function that combines the discrete laplacian operator and an adaptation of the Lanczos kernel. Differently from other works that propose surface fairing approaches we deal mainly with voxelized models created by artists for games which led us to design a filtering approach that smoothes strongly in high frequency
regions to remove the jagging effects of the sampling and less intensively in the low frequency regions to preserve the natural behavior of the model. The overall aim of this work is to propose a simple methodology in which it is efficient and easy to use voxel manipulation techniques to produce a final boundary representation of the model together with the appearance function codified in a texture atlas. The proposed method produced very promising results and enabled us to extract smooth texturized models that preserve the features of the original volumetric object at interactive times.
Downloads:
-> Fast Polygonization and Texture Map Extraction From Volumetric Objects Based on Surface Fairing Using a Modified Discrete Laplacian Operator (Article)
Additional Credits:
- The Warhammer Tank in the article was created by SaneDisruption and extensively used to test the technique. The other models were created by Westwood Studios. Demo Truck and Kirov Airship comes with the vanilla Red Alert 2. Yuri Head is in Yuri's Revenge expansion pack.
This article was sent and accepted as one of the top ten full papers for SBGAMES 2010.
Fast Polygonization and Texture Map Extraction From Volumetric Objects explains the 3D Modelizer feature that is being developped for the beta versions of Voxel Section Editor III.
The Brazilian Symposium on Computer Games and Digital Entertainment is the most important brazilian symposium in game development and research, covering several areas from computer graphics to artificial inteligence, storytelling research, among other topics. It is the second biggest computer science conference in Brazil, only behind SBC's main event. (Note: SBC is the Brazilian Computing Society, a sort of equivalent organization to ACM, but in Brazil).
All articles must be written in english, however, at the event we were allowed to present them in portuguese, since most of the people who were in the conference are brazilians.
The motivation behind using Voxels for modelling purposes came from Project Perfect Mod Voxels forum.
How come people post much more voxels than 3D models in our forums? While it is notorious that PPM started with Tiberian Sun and the amount of modders who mod both Tiberian Sun and Red Alert 2 here still bypass the amount of those who work with the 3D SAGE engine used in Command & Conquer Renegade and newer games, we've noticed that even outside PPM, the number of artists who are able to create properly textured models for these newer games are very limited. The reason is very simple: in order to create complete 3D graphics used by these games, artists need to master extensive computer graphics concepts, including maths... and perhaps some physics as well. The existing conventional tools are not intuitive for the manipulation of textures: splitting the model in UV space is not a trivial task; users are not able to see where in the model they are painting, when they paint textures using Photoshop and other tools like that; normal maps shows colours instead of directional vectors; specular map is hard to understand; etc. There are tools like ZBrush that simplifies part of this process by allowing users to paint directly in the model, but they are expensive and they are still based in texture.
In this work, we understand that the use of textures is an artifact to optimize the use of the 3D model in the video card and it shouldn't be a duty from the artist to do that. Artists should express their ideas by modelling the shape and painting with voxels instead, just like what Voxel Section Editor III does, although we understand that VXLSE III is not the ideal program to create 3D models for newer games, since it has been created with the limitations of Red Alert 2 engine in mind since the beggining: limiting colour palette, normals and how it deals with skeleton hierarchy and animations.
This full paper explains how to make this process viable in a future 3D modelling program and providing the results in interactive time. It explains how the program should transform a model based on voxels in a 3D polygonal model with textures, by generating an initial mesh and manipulating the attributes of each vertex to make it look more smoothed, keeping the details added by the user. And it also shows how to generate a texture atlas that covers every face of the model automatically. The article does not get in details how to optimize the 3D mesh that it generates reducing the amount of polygons that it holds.
The method explained in this article has a couple of limitations that will be worked in the future. It may generate wrong results in the sections of the model that have a couple of topological problems, such as voxels whose neighbors are only linked by vertexes or edges, although it deals correctly with all other topoligical problems. Also, the texture atlas extraction technique is a bit naive and it may generate far too many partitions, decreasing the quality of the texture and the efficience of a future mesh optimization technique.
Abstract:
This work proposes a new method for the polygonization and texture map extraction from volumetric objects based on a polyhedral surface extraction and surface fairing approach. The surface faring approach is based on a mesh signal processing technique that uses an approximation of an adaptive low-pass filtering based on a function that combines the discrete laplacian operator and an adaptation of the Lanczos kernel. Differently from other works that propose surface fairing approaches we deal mainly with voxelized models created by artists for games which led us to design a filtering approach that smoothes strongly in high frequency
regions to remove the jagging effects of the sampling and less intensively in the low frequency regions to preserve the natural behavior of the model. The overall aim of this work is to propose a simple methodology in which it is efficient and easy to use voxel manipulation techniques to produce a final boundary representation of the model together with the appearance function codified in a texture atlas. The proposed method produced very promising results and enabled us to extract smooth texturized models that preserve the features of the original volumetric object at interactive times.
Downloads:
-> Fast Polygonization and Texture Map Extraction From Volumetric Objects Based on Surface Fairing Using a Modified Discrete Laplacian Operator (Article)
Additional Credits:
- The Warhammer Tank in the article was created by SaneDisruption and extensively used to test the technique. The other models were created by Westwood Studios. Demo Truck and Kirov Airship comes with the vanilla Red Alert 2. Yuri Head is in Yuri's Revenge expansion pack.