• 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
menohack

Finding pixel offset for silhouette shadow mapping

2 posts in this topic

I've looked around but I can't figure out if D3D will give me what I need. I want to create a silhouette map to implement this paper. What I need is an x-y offset of a line relative to the center of the pixel. That is, when a wireframe model is rendered D3D picks the closest pixel to the line and draws it. I want to know where exactly the line cuts through the pixel. This will be the value stored in my silhouette map. Is there any way to get this in D3D11? The x-y values of POSITION are just the pixel index plus 0.5. Do I have to do this on the cpu or use a compute shader or is there an easier way? From the attached image I want to find point O. The paper passes in the endpoints of the line segments but it would be a lot easier if D3D gave me access to some of the values that it computes at the rasterization state. Thanks.

0

Share this post


Link to post
Share on other sites

I can't think of any automatic ways that this can be done through a pipeline feature or anything like that.  The closest thing you will get is the pixel location in the pixel shader, but that will give you the address of the center of the pixel and not the central point of your line within that pixel.

 

If you pass the two endpoints as vertex attributes though, then you should be able to get a linearly interpolated approximation of the value.  Unfortunately the interpolation is performed for the pixel (and not the line) so it would again be with respect to the center of the pixel...

 

However, you are essentially just doing line intersection tests within the boundary of the pixel, which should be fairly fast operation and the lines are always oriented in the same way with respect to the pixel center.  That should let you optimize the process a bit and help you determine which of the four cases you have in your pixel shader.  I would say to give it a shot and see if you can implement it yourself - I think it should be possible to get working in an efficient manner.

 

By the way, have you considered using multi-sampling?  I assume not, since this is an anti-aliasing technique, but it would give you access to the sample coverage information if you are using it.

1

Share this post


Link to post
Share on other sites

Thanks! I'm trying to pass the other two vertices of a triangle in as vertex attributes. Then I'll pass all three to the pixel shader and compute the intersections. It may be possible to do this in the geometry shader before rasterization but I am not familiar enough to know. I'm still going to render in wireframe mode to reduce the number of pixel threads.

 

I'm also not familiar with how multi-sampling works below the covers.

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