• 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

Help with Stencil Test and Deferred Shading [SOLVED]

0 posts in this topic

I'm having real trouble getting my stencil test to work correctly with a basic deferred shading implementation. I'm aware there are other options, but I really need to get the stencil test working because I plan to try and use stencil volume shadows. I've done pretty much this exact implementation before, and it worked fine, so I'm really at a loss for what the problem is.
In any case, the real problem is that the stencil test doesn't seem to properly take account of the first pass depth buffer, even though depth test is on during the stencil pass. In addition, the stencil test seems corrupted when it's behind the geometry. Three screenshots below and then stencil and depth buffer grab.
[attachment=19744:stencil test ex 1.png]
In this first image, the light volume that I'm rendering to the stencil buffer and then again in the light pass is behind terrain geometry. So why is it visible? 
[attachment=19745:stencil test ex 2.png]
This second image looks alright from the other side, although you can see underneath the geometry a bit again.


[attachment=19746:stencil test ex 3.png]

The third image shows the output of the stencil past, so clearly the geometry is ok. 


[attachment=19747:FrameStencil_0021_0099_Pre.png] [attachment=19748:FrameDepth_0021_0099_Pre.png]
Sorry they're so small. It's too slow to capture with any larger framebuffer size.


Here's the rendering code:

// geometry pass
m_gbuffer->bindWrite();    // binds fbo
m_gbuffer->setDrawBuffers(0, m_num_drawbuffers); // glDrawBuffers(num_buffers, buffers)







// light pass
glDrawBuffer(GL_COLOR_ATTACHMENT0 + m_num_drawbuffers);   // same fbo, so same depth buffer, but different texture for light pass
m_gbuffer->bindToTextures();    // bind fbo textures for shaders



// stencil pass
        glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);


	glStencilFunc(GL_ALWAYS, 0, 0);
	glStencilOpSeparate(GL_BACK, GL_KEEP, GL_INCR, GL_KEEP);
	glStencilOpSeparate(GL_FRONT, GL_KEEP, GL_DECR, GL_KEEP);



// light pass
        glStencilFunc(GL_NOTEQUAL, 0, 0xFF);

	glBlendFunc(GL_ONE, GL_ONE);







Thanks for your time. I appreciate any suggestions.





I swear, posting on these forums just makes me think differently and I solve it easily. The glStencilOpSeparate needs to be set to GL_INCR_WRAP or GL_DECR_WRAP respectively. The WRAP portion means that decrementing at 0 will wrap the buffer to 255, and incrementing at 255 will wrap the buffer to 0. Very useful, yet my previous code that worked did not use WRAP. It must be somewhat platform dependent. Hope this can help someone.


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