• Advertisement
  • Popular Tags

  • Popular Now

  • Advertisement
  • Similar Content

    • By lxjk
      Hi guys,
      There are many ways to do light culling in tile-based shading. I've been playing with this idea for a while, and just want to throw it out there.
      Because tile frustums are general small compared to light radius, I tried using cone test to reduce false positives introduced by commonly used sphere-frustum test.
      On top of that, I use distance to camera rather than depth for near/far test (aka. sliced by spheres).
      This method can be naturally extended to clustered light culling as well.
      The following image shows the general ideas

       
      Performance-wise I get around 15% improvement over sphere-frustum test. You can also see how a single light performs as the following: from left to right (1) standard rendering of a point light; then tiles passed the test of (2) sphere-frustum test; (3) cone test; (4) spherical-sliced cone test
       

       
      I put the details in my blog post (https://lxjk.github.io/2018/03/25/Improve-Tile-based-Light-Culling-with-Spherical-sliced-Cone.html), GLSL source code included!
       
      Eric
    • By Ty Typhoon
      ...if you got time to read and answer i would be happy . 
       
      So me and my co try to do a game.
      It should be in unity couse my co do everything in this engine.
       
      We got the rpg package from evila for inventor, but it only runs on pc right now.
       
      I like to make a online store for guns in the game and a multiplayer open world that runs on pc, android, mobile, ps4, xbox one. 
      Somebody told me that you "only" need to program it like so and that its possible in every engine...
       
      So if you are one of the lucky guys who could help me out or programm that, or even if you know a newer better package for maybe unreal which offers that - please let me know now.
    • By Octane_Test
      I am developing a mini golf game in Scenekit. I have applied dynamic physics body to the ball and static physics body to the grass surface and the brick walls show in this image.
      Issue:
      When I apply the force to the ball, the ball’s linear and angular speeds change as shown in the graphs.  The ball’s speeds don’t reduce to zero (so that the ball can stop) but remains constant after certain value.
      Ball linear speed graph
      Ball angular speed graph
      Analysis Tests:
      When I increase the values to both the rolling friction and the friction, the ball speed is reduced quickly but remains constant after certain value (similar to the above graphs). When I increase the values of the linear damping and the angular damping, the ball speed behavior is same as the point #1. When I set the gravity value to -9.8 m/s2, the ball’s linear speed remains constant after 0.1 m/s. If I reduce the gravity value to -5 m/s2, the ball’s linear speed remains constant after 0.05 m/s. The friction, linear friction, linear damping and angular damping are same throughout the motion of the ball.
      There is 1 millimeter overlapping between the ball and the surface of the golf course.
      Questions:
      From the analysis test #3, I think the gravity is causing the constant ball speed issue. Is my assumption correct? If yes, how can I fix the issue? I can’t remove the gravity field as without the gravity field the ball will not roll along the grass and it will slide. Why the friction and the damping properties are not affecting the ball speed after certain value?
      Are there any other physics properties can cause such issue?
      From the analysis test #5, are there any chances that the ball is receiving upward push to correct the position of the ball?
      Solutions:
      If I increase the physics timestep from 60 FPS to 200 FPS, the issue is resolved. I am not able to understand how this change can fix this issue? After reducing the gravity value to -1 m/s2 and physics simulation speed to 4 (4 times fast physics simulation), the issue is fixed. Again, I am not able to understand how this change fix the issue? I would appreciate any suggestions and thoughts on this topic. Thank you.
    • By stale
      I'm continuing to learn more about terrain rendering, and so far I've managed to load in a heightmap and render it as a tessellated wireframe (following Frank Luna's DX11 book). However, I'm getting some really weird behavior where a large section of the wireframe is being rendered with a yellow color, even though my pixel shader is hard coded to output white. 

      The parts of the mesh that are discolored changes as well, as pictured below (mesh is being clipped by far plane).

      Here is my pixel shader. As mentioned, I simply hard code it to output white:
      float PS(DOUT pin) : SV_Target { return float4(1.0f, 1.0f, 1.0f, 1.0f); } I'm completely lost on what could be causing this, so any help in the right direction would be greatly appreciated. If I can help by providing more information please let me know.
    • By Sandman Academy
      Downloadable at:
      https://virva.itch.io/sandman-academy
      https://gamejolt.com/games/sandmanacademy/329088
      https://www.indiexpo.net/en/games/sandman-academy
      https://www.gamefront.com/@sandmanacademy
      http://www.indiedb.com/games/sandman-academy
  • Advertisement
  • Advertisement

how to understand dxut CDXUTDirectionWidget class

Recommended Posts

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

Share this post


Link to post
Share on other sites
Advertisement

Probably easier to ask what you don't understand about it.

Do you understand what the basis vectors are?  Do you understand what the cross product operations do? What about the function is confusing to you?

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


  • Advertisement