• Announcements

    • khawk

      Download the Game Design and Indie Game Marketing Freebook   07/19/17

      GameDev.net and CRC Press have teamed up to bring a free ebook of content curated from top titles published by CRC Press. The freebook, Practices of Game Design & Indie Game Marketing, includes chapters from The Art of Game Design: A Book of Lenses, A Practical Guide to Indie Game Marketing, and An Architectural Approach to Level Design. The GameDev.net FreeBook is relevant to game designers, developers, and those interested in learning more about the challenges in game development. We know game development can be a tough discipline and business, so we picked several chapters from CRC Press titles that we thought would be of interest to you, the GameDev.net audience, in your journey to design, develop, and market your next game. The free ebook is available through CRC Press by clicking here. The Curated Books The Art of Game Design: A Book of Lenses, Second Edition, by Jesse Schell Presents 100+ sets of questions, or different lenses, for viewing a game’s design, encompassing diverse fields such as psychology, architecture, music, film, software engineering, theme park design, mathematics, anthropology, and more. Written by one of the world's top game designers, this book describes the deepest and most fundamental principles of game design, demonstrating how tactics used in board, card, and athletic games also work in video games. It provides practical instruction on creating world-class games that will be played again and again. View it here. A Practical Guide to Indie Game Marketing, by Joel Dreskin Marketing is an essential but too frequently overlooked or minimized component of the release plan for indie games. A Practical Guide to Indie Game Marketing provides you with the tools needed to build visibility and sell your indie games. With special focus on those developers with small budgets and limited staff and resources, this book is packed with tangible recommendations and techniques that you can put to use immediately. As a seasoned professional of the indie game arena, author Joel Dreskin gives you insight into practical, real-world experiences of marketing numerous successful games and also provides stories of the failures. View it here. An Architectural Approach to Level Design This is one of the first books to integrate architectural and spatial design theory with the field of level design. The book presents architectural techniques and theories for level designers to use in their own work. It connects architecture and level design in different ways that address the practical elements of how designers construct space and the experiential elements of how and why humans interact with this space. Throughout the text, readers learn skills for spatial layout, evoking emotion through gamespaces, and creating better levels through architectural theory. View it here. Learn more and download the ebook by clicking here. Did you know? GameDev.net and CRC Press also recently teamed up to bring GDNet+ Members up to a 20% discount on all CRC Press books. Learn more about this and other benefits here.
Sign in to follow this  
Followers 0
Slaaitjuh

Texture matrix from triangle

2 posts in this topic

Hello,

 

I was wondering if there's anyone that can help me with the following idea. I am currently working on a CSG library. I made a function to import models. The models get converted to planes, and later on rebuild to vertices. For material editing I am using texture matrices per plane. I would like to continue this, but I am facing a problem/idea:

 

When reading an existing model, I can get the position, normal and texture coordinates for a given vertex/triangle. Since I can get the three vertices and texture coordinates of a triangle, I was wondering if there is a way to construct a Matrix from those parameters to recreate the texture coordinates after the CSG process.

This would mean that the matrix would be able to calculate texture coordinates by transforming the vertex position.

 

The reason I would like for this to work, is that I can reuse the texture coordinates in the models, making the initial model look much better.

 

I would prefer examples in C# if I have a choice, but any language will do :-) Idea's are very welcome as well. Any clarification can be provided also.

 

Thanks,

0

Share this post


Link to post
Share on other sites

I'm not completely clear about your intended use case, but I'll give it a shot anyways :)  So you have a process that converts a 3D mesh (which is a list of vertices + triangle connectivity information) into a new representation which is a list of planes, and the locations within those planes that define the vertex locations - is that correct?

 

Then if you want to have a single transformation that produces the texture coordinates from the positions, there are some strict limitations that would be required that I think would make this impractical.  You would need to have a uniform 3D mesh surface area to texture space mapping, which typically is not the case.  In addition, the production of the original texture coordinates must respect the mapping to and from position information, which is also not normally the case since texture information is just packed in as efficiently as possible.

 

So if I have understood what you want properly, then I don't think there is a generic way to map between positions and texture coordinates unless you impose this mapping on the original input models.  Have you considered just storing the texture data along with your planar representation of the positions?

0

Share this post


Link to post
Share on other sites

I'm not completely clear about your intended use case, but I'll give it a shot anyways smile.png  So you have a process that converts a 3D mesh (which is a list of vertices + triangle connectivity information) into a new representation which is a list of planes, and the locations within those planes that define the vertex locations - is that correct?

 

Then if you want to have a single transformation that produces the texture coordinates from the positions, there are some strict limitations that would be required that I think would make this impractical.  You would need to have a uniform 3D mesh surface area to texture space mapping, which typically is not the case.  In addition, the production of the original texture coordinates must respect the mapping to and from position information, which is also not normally the case since texture information is just packed in as efficiently as possible.

 

So if I have understood what you want properly, then I don't think there is a generic way to map between positions and texture coordinates unless you impose this mapping on the original input models.  Have you considered just storing the texture data along with your planar representation of the positions?

 

I am sorry for replying this late, I did not notice there was a reaction. Thanks for that. 

 

Your first assumption is correct. The problem is that we are performing CSG on these planes, which creates sub vertices etc etc. A way to recalculate the texture coordinates ( in my head, that is) was to produce a uniform texture matrix that somehow preserves the original intention of the texture map. This would be a matrix per plane. I guess I have to agree with you that it would be impractical, maybe even impossible. 

 

I considered barycentric coordinates (remember which plane had which vertices / uv, and do the math) yet the results were often _not spot on_. A lot of vertices got little offsetted texture coordinates which looks unnatural. 

 

Another way was to do planar world mapping, but I wanted to avoid that since that only results in something nice on a box. Mapping a sphere or cone with this is not pretty.

 

The previous version I was working on involved creating the planes, looking up the texture coordinates and interpolate them along with the vertex data. The problem I have with this, is that it requires a lookup table from the original model to the CSG model. This is a weak link, which I'd like to avoid.

 

Do you have any tips/ideas I did not try yet?

 

Thanks again for your clear explanation.

0

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0