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      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.
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Multisampling is a compromise for people who really want to use supersampling, but can't afford it.

The idea is simple: instead of increasing the resolution for all rendering, what if we do triangle rasterization and depth/stencil tests at the higher resolution, but leave pixel shading and texture lookups at the original, lower resolution?

Where standard rendering goes like:

  • For each final output pixel covered by a triangle:
    • Run the pixel shader
    • Perform the depth test
    • Write the pixel colorAnd supersampling is:

      • For each high resolution supersampled pixel covered by a triangle:
        • Run the pixel shader
        • Perform the depth test
        • Write the pixel color
        • After all geometry is drawn, downsample the high resolution image to the final sizeThe process for multisampling is:

          • For each final output pixel covered by a triangle:
            • Run the pixel shader
            • For each high resolution multisampled pixel covered by the intersection of the triangle and the current output pixel:
              • Perform the depth test
              • Write the pixel color
              • After all geometry is drawn, downsample the high resolution image to the final sizeUnlike supersampling, which can be implemented by drawing to a standard rendertarget and using a pixel shader to apply the final downsize filter, multisampling requires dedicated hardware support. In XNA, it is enabled by adding this to your Game constructor:

                graphics.PreferMultiSampling = true;Because triangle rasterization and depth testing are performed at the higher resolution, multisampling is every bit as good as supersampling at combating triangle edge and geometry aliasing. But because the pixel shader only runs once per final output pixel, it does not help at all with texture map or shader aliasing.

                This is an important and easily missed point: multisampling only knows about the edges of polygonal geometry.

                Multisampling can smooth the edges of triangles, and also the edges formed where one zbuffered triangle intersects another, but it knows nothing about what happens within the interior of each triangle. Texturing, shading, and lighting produce exactly the same results as if multisampling was not used at all (think about it: the pixel shader runs just once, then we write out 2 or 4 copies of the same color, after which the downsample filter averages these identical colors, producing the exact same value we started with). If your triangles have interior borders caused by texture lookups or shader code (for instance the border of an alpha cutout sprite), multisampling will be irrelevant. This often surprises people when they see aliasing on cutout sprites and turn on multisampling in an attempt to fix it, but nothing changes. Yet this is the nature of the beast. If you want to antialias alpha cutout borders within a triangle, you need supersampling, or one of the texture/shader based techniques I will talk about later.

                So why is multisampling popular? (and it is very popular, to the extent where many people confuse the generic term "antialiasing" with the specific technique "multisampling")

                Simple: it's cheap. On some hardware (notably Xbox 360) it can be very cheap indeed.

                Remember that the GPU is an asynchronous parallel processing pipeline. Multisampling increases the cost of some stages along this pipeline (notably rasterization, depth/stencil testing, and framebuffer writes), but it does not affect the areas that are most often performance bottlenecks (vertex fetch, vertex shading, texture fetch, and pixel shading). Adding work to things that were not the perf bottleneck can sometimes even be entirely free, so multisampling often turns out to improve visual quality for low cost.

                Even if you are bottlenecked by framebuffer bandwidth, hardware designers are clever and can pull all sorts of neat silicon tricks to make multisampling efficient, taking advantage of the coherency where the same color value is usually written many times in a row. Why waste memory bandwidth saying "write X, ok, write X again, and again, and one more 'gain", when you could send just a single copy of X over the bus, followed by a couple of bit flags indicating which multisamples this pixel shader result should cover?

                Oh yeah, before I go I should show you how it looks. Here's our favorite tank model, first with no antialiasing, then using 4x multisampling:

                5001.image_5F00_1EBD84D2.png 2352.image_5F00_6AA8E57E.png

                And the same images zoomed in:

                5008.image_5F00_4E982693.png 6177.image_5F00_75663CD3.png



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