• 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
domok

3D Rain Particle System

6 posts in this topic

Hi

I'm working on a 3d rain particle system. Till now I have used billboards (with ID3DXSprite) but this doesn't look nice if you look up to the sky because then the rain drops (they are more like lines) still look the same. The lines can't always show the camera but I don't know how to make it look real.
Another problem with billboards is that you can't make diagonal rain (or I haven't found out how...).
The rain can't just be a 2D overlay because it interacts with the terrain.

What is the best way to draw real looking and always correctly oriented rain drops?
0

Share this post


Link to post
Share on other sites
[size=3][font=arial,helvetica,sans-serif]Would depend on your engine, but I'd try [/font][/size][size=3][font=arial,helvetica,sans-serif]Geometry Instancing[/font][/size] to use real rain drop shapes.

[url="http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter03.html"]http://http.develope..._chapter03.html[/url]

But billboards are still fine for slower machines, not sure what options DX9 gives you on controlling them, cant you rotate them? can you maybe shift the lower UVs to move the line to match the fall direction? can you lock a rotation so it wont look directly at the camera but still follow it position.

Anyway Good luck !
0

Share this post


Link to post
Share on other sites
The problem with rotating the billboards is that the rotation depends on the position of the camera.

If the drops fall down with a vector (1, -1, 0) and your view direction is parallel to the yz-plane then the lines should be diagonal but if your view is parallel to the xy-plane the lines should be straight down.

I'd like to have them fall straight down correctly first. I disabled billboarding and the result was much better, but now if you watch from a certain angle, you can see almost no drops, because the quads are parallel to the view direction.

What I need to have is billboarding that only affects the y-axis. Is that what you meant with:

[quote]can you lock a rotation so it wont look directly at the camera but still follow it position.[/quote]

Anyway I don't know if I can, I probably do but I don't know how...?
0

Share this post


Link to post
Share on other sites
Ok it was easier than I thought.

You just calculate the angle between the view direction (with y = 0) and the vector (0, 0, 1), then create a rotation matrix around y-axis with this angle.

I think I'll find out the rest with diagonal rain

Thanks!
0

Share this post


Link to post
Share on other sites
Here's how to build a matrix that keeps it vertical and facing the camera (taken from http://www.gamedev.net/topic/546352-billboard-rotating-along-one-axis/ ):

One axis is fixed, 'up' is always (0,1,0)
'Forward' will obviously be (cameraPosition - raindropPosition) normalized.
'Right' is the cross product of 'up' and 'forward'
'forward' needs to be made orthogonal by another cross product of 'right' and 'up'

The columns of the transformation matrix are 'right'|'up'|'forward'|'position'
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