• 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
Migi0027

DX11
DX11 - API - Disadvantage of vector multiplication.

9 posts in this topic

Hi guys, wink.png

 

some few times multiplying vectors of same kind becomes a must, and so I do it, but I need to do multiply the components individually (Not a problem). But the class D3DVECTORX (2, 3, 4...), doesn't have an multiply operator with an overload for other vectors of it's kind, why not?

 

Why has the developers chosen that? ( Disadvantages ? )

 

Thanks, as usual.

-MIGI0027

0

Share this post


Link to post
Share on other sites

Probably because it can be confused with a dot product, which also takes two vectors as arguments. E.g. I use SlimDX and the math library there doesn't even have such an overload, but explicitly named functions for both dot and a so-called modulate. Counter example: HLSL uses modulate for *, but has an intrinsic for dot (or  mul for matrix vector multiplication).

 

If you don't find such a modulate function, it should be easy write a free function :wink:

2

Share this post


Link to post
Share on other sites

It is likely because multiplying one vector by another component wise doesn't make sense as an operation on vector spaces. Under what circumstances do you need to use component wise multiplication?

0

Share this post


Link to post
Share on other sites

It is likely because multiplying one vector by another component wise doesn't make sense as an operation on vector spaces. Under what circumstances do you need to use component wise multiplication?

 

Sure it does, its just a non-uniform scale. Granted its not the most common operation for 3D graphics, but its hardly unheard of, and it has wide applicability in other domains. In my own vector math library, I overload operator * and operator / between vectors to mean piecewise multiplication and piecewise division (non-uniform scaling), and between vectors and scalars by extending the scalar to a vector of same rank (uniform scaling). I feel that this configuration best satisfies the recommended design principles of "principle of least surprise" (particularly regarding operator associativity and operator precedense) and "do as the ints do". I provide for the dot, cross (and 2D psuedo-cross) product as (non-member) functions, along with some other useful ones. I'm pretty happy with how orthogonal this makes things, and while its not as terse as with operator overloading, it forces you to state the order of operations explicitly.

1

Share this post


Link to post
Share on other sites

 

It is likely because multiplying one vector by another component wise doesn't make sense as an operation on vector spaces. Under what circumstances do you need to use component wise multiplication?

 

Sure it does, its just a non-uniform scale. Granted its not the most common operation for 3D graphics, but its hardly unheard of, and it has wide applicability in other domains. In my own vector math library, I overload operator * and operator / between vectors to mean piecewise multiplication and piecewise division (non-uniform scaling), and between vectors and scalars by extending the scalar to a vector of same rank (uniform scaling). I feel that this configuration best satisfies the recommended design principles of "principle of least surprise" (particularly regarding operator associativity and operator precedense) and "do as the ints do". I provide for the dot, cross (and 2D psuedo-cross) product as (non-member) functions, along with some other useful ones. I'm pretty happy with how orthogonal this makes things, and while its not as terse as with operator overloading, it forces you to state the order of operations explicitly.

I think we have differing definitions of vectors.

0

Share this post


Link to post
Share on other sites

Not really. Strictly speaking, I suppose non-uniform-scaling isn't common in processing things like geometry, but it certainly has a meaning that's rational enough to be useful, and vectors and vector spaces have other applications. For example, if you consider a color space (like RGB), as a vector space, then operations like gamma-correction are just non-uniform scales. We can argue mathematical pedantries all day but when we're being pragmatic there's not a strong argument to be made for keeping to a 100% correct, mathematical definition of vectors intact (unless you're specifically working in a pure-math domain, and want the type system to chain you to the mathematical definition intentionally). For example, even though vectors and points are entirely different mathematical concepts, they can be represented in unified form, and often are, without making any dangerous compromises.

Edited by Ravyne
0

Share this post


Link to post
Share on other sites

 

 

It is likely because multiplying one vector by another component wise doesn't make sense as an operation on vector spaces. Under what circumstances do you need to use component wise multiplication?

 

Sure it does, its just a non-uniform scale. Granted its not the most common operation for 3D graphics, but its hardly unheard of, and it has wide applicability in other domains. In my own vector math library, I overload operator * and operator / between vectors to mean piecewise multiplication and piecewise division (non-uniform scaling), and between vectors and scalars by extending the scalar to a vector of same rank (uniform scaling). I feel that this configuration best satisfies the recommended design principles of "principle of least surprise" (particularly regarding operator associativity and operator precedense) and "do as the ints do". I provide for the dot, cross (and 2D psuedo-cross) product as (non-member) functions, along with some other useful ones. I'm pretty happy with how orthogonal this makes things, and while its not as terse as with operator overloading, it forces you to state the order of operations explicitly.

I think we have differing definitions of vectors.

 

Are you implying that a useful construct for computer graphics (non-uniform scaling, which is used in editors all the time) should not be allowed because of the mathematical definition of a vector?  Non-uniform scaling is very clearly used frequently - are you saying that such an operation should not be possible?

 

I just don't see the logic in the argument you are making here...

0

Share this post


Link to post
Share on other sites


some few times multiplying vectors of same kind becomes a must, and so I do it, but I need to do multiply the components individually (Not a problem). But the class D3DVECTORX (2, 3, 4...), doesn't have an multiply operator with an overload for other vectors of it's kind, why not?

 

Why are you asking about D3DVECTOR structs in a topic titled with "DX11"? DirectX 11 has DirectXMath, which has the XMVECTOR class, which has an operator for component multiplication.

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

  • Similar Content

    • By bowerbirdcn
      hi, guys, how to understand the math used in CDXUTDirectionWidget ::UpdateLightDir 
      the  following code snippet is taken from MS DXTU source code
       
        D3DXMATRIX mInvView;
          D3DXMatrixInverse( &mInvView, NULL, &m_mView );
          mInvView._41 = mInvView._42 = mInvView._43 = 0;
          D3DXMATRIX mLastRotInv;
          D3DXMatrixInverse( &mLastRotInv, NULL, &m_mRotSnapshot );
          D3DXMATRIX mRot = *m_ArcBall.GetRotationMatrix();
          m_mRotSnapshot = mRot;
          // Accumulate the delta of the arcball's rotation in view space.
          // Note that per-frame delta rotations could be problematic over long periods of time.
          m_mRot *= m_mView * mLastRotInv * mRot * mInvView;
          // Since we're accumulating delta rotations, we need to orthonormalize 
          // the matrix to prevent eventual matrix skew
          D3DXVECTOR3* pXBasis = ( D3DXVECTOR3* )&m_mRot._11;
          D3DXVECTOR3* pYBasis = ( D3DXVECTOR3* )&m_mRot._21;
          D3DXVECTOR3* pZBasis = ( D3DXVECTOR3* )&m_mRot._31;
          D3DXVec3Normalize( pXBasis, pXBasis );
          D3DXVec3Cross( pYBasis, pZBasis, pXBasis );
          D3DXVec3Normalize( pYBasis, pYBasis );
          D3DXVec3Cross( pZBasis, pXBasis, pYBasis );
       
       
      https://github.com/Microsoft/DXUT/blob/master/Optional/DXUTcamera.cpp
    • By YixunLiu
      Hi,
      I have a surface mesh and I want to use a cone to cut a hole on the surface mesh.
      Anybody know a fast method to calculate the intersected boundary of these two geometries?
       
      Thanks.
       
      YL
       
    • By hiya83
      Hi, I tried searching for this but either I failed or couldn't find anything. I know there's D11/D12 interop and there are extensions for GL/D11 (though not very efficient). I was wondering if there's any Vulkan/D11 or Vulkan/D12 interop?
      Thanks!
    • By lonewolff
      Hi Guys,
      I am just wondering if it is possible to acquire the address of the backbuffer if an API (based on DX11) only exposes the 'device' and 'context' pointers?
      Any advice would be greatly appreciated
    • By MarcusAseth
      bool InitDirect3D::Init() { if (!D3DApp::Init()) { return false; } //Additional Initialization //Disable Alt+Enter Fullscreen Toggle shortkey IDXGIFactory* factory; CreateDXGIFactory(__uuidof(IDXGIFactory), reinterpret_cast<void**>(&factory)); factory->MakeWindowAssociation(mhWindow, DXGI_MWA_NO_WINDOW_CHANGES); factory->Release(); return true; }  
      As stated on the title and displayed on the code above, regardless of it Alt+Enter still takes effect...
      I recall something from the book during the swapChain creation, where in order to create it one has to use the same factory used to create the ID3D11Device, therefore I tested and indeed using that same factory indeed it work.
      How is that one particular factory related to my window and how come the MakeWindowAssociation won't take effect with a newly created factory?
      Also what's even the point of being able to create this Factories if they won't work,?(except from that one associated with the ID3D11Device) 
  • Popular Now