• 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
Alundra

Compute Shader ThreadGroup Order

5 posts in this topic

Hi all,

Compute shader works using a split of work by ThreadGroup.

You can use a groupshared to have a cache to reuse data with the next ThreadGroup.

The problem is if you want to store an offset based on each cell who has a count the order is important.

My question is simple : Compute Shader works using a linear dispatch ?

I mean, does it work running thread group left to right and top to bottom ?

Thanks

0

Share this post


Link to post
Share on other sites

It isn't entirely clear what you are asking for here, so I'll take my best shot.  The way that you define your thread group and dispatch dimensions is usually intended to model your dataset that is being processed.  Generally, if the data set is a 2D texture, then your dispatch and thread groups are sized accordingly to address chunks of the 2D region (and your z coordinates will be 1).  Alternatively, if you are processing a 1D buffer of data, then you would just use the x-coordinate for addressing.

 

The linear index for a complete dispatch is available in the SV_GroupIndex, which includes all thread groups together.  This is good when you are processing a linearly stored data set.  Otherwise you can choose one of the other System Value semantics (SV_GroupID, SV_GroupThreadID, or SV_DispatchThreadID) to get a better addressing for your problem.

 

The group shared memory is intended for sharing intermediate results among the threads in a thread group.  So typically you would use the SV_GroupThreadID system value to address it, since it is local to the thread group.  If you wanted a linear index for your group shared, then you can either choose a 1D thread group shape, or you can flatten your indices manually based on the shape of the thread group.  However, I would highly recommend to just choose your thread group shape according to the data you are processing so that you can skip any additional math in your shader.

 

Does that help clarify the issue?

1

Share this post


Link to post
Share on other sites

Like Jason mentioned, group shared memory is only for sharing data within a single thread group. You can't use it to share memory with other thread groups. There's also no ordering guarantees on thread groups (the hardware can and will execute multiple thread groups in parallel) so you can't rely on that in your algorithms.

0

Share this post


Link to post
Share on other sites

Thanks for answer.
The problem is I need to store a list of indices in an array and I need to store a StartOffset.

The data need to be ordored so, and the only way found is to not use sync and has worst case indices buffer size.

That work but that use a lot of wasted memory (width*height*depth*MaxIndex).

No workaround exist to avoid this ? On CPU it's easy since the offset just need to be added by one each time an index is added.

0

Share this post


Link to post
Share on other sites

You'll want to use an AppendStructuredBuffer for this. It essentially has a hidden counter, and whenever you call Append it will perform a global atomic on the counter value. Just keep in mind that the resulting order of the elements will be non-deterministic in most cases, since the appends are happening in parallel.

0

Share this post


Link to post
Share on other sites

Ok but still the problem of start offset.

The data needs to be StartOffset and Count (uint2).

Read the length of the buffer as start offset ?

The start offset and the order of indices who is added is important.

Edited by Alundra
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