1. 03 Jun, 2019 1 commit
  2. 28 Feb, 2018 1 commit
    • Ken Martin's avatar
      update glsl code to 140 standards · 3c999de5
      Ken Martin authored
      While maintaining backwards compatibility at least
      update our code to use the more modern in/out
      qualifiers as opposed to attribute/varying  Also
      remove old glsl 120 if statements as we no longer support
      it and also remove a performance issue in querying the
      gl major minor version on every shader test.
      3c999de5
  3. 08 Mar, 2016 1 commit
  4. 16 Oct, 2015 1 commit
    • Ken Martin's avatar
      Fix a couple issues with lic · eb81836d
      Ken Martin authored
      there was a texture pasting size error int he old code and both
      versions were eliminating the mask value when they should not.
      eb81836d
  5. 09 Oct, 2015 1 commit
    • Ken Martin's avatar
      Add android vr example and fixes to support it · c8fd8f3e
      Ken Martin authored
      This topic adds a volume rendering example to android builds.  It also
      fixes a number of issues to make it work with android including on
      Samsung devices which have a different OpenGL driver.
      
      VR use of 1D textures have been replaced with 2D textures as
      1D textures are not supported on OpenGL ES.
      
      Some minor build inprovements are included as well.
      c8fd8f3e
  6. 20 May, 2015 1 commit
  7. 11 Mar, 2015 1 commit
  8. 13 Sep, 2013 1 commit
    • Burlen Loring's avatar
      Surface LIC : parallelization & fine tuning features · ad4dddfc
      Burlen Loring authored
      * Parallelization:
      Support for Multiblock datasets and MPI parallel usage. Three compositing
      strategies are provided, with a heuristic to automatically make a reasonable
      selection between them. [1] INPLACE, [2] INPLACE_DISJOINT, [3] BALANCED.
      The inplace strategy processes data where it falls given its parallel domain
      decomposition and projection to the screen. For simple surfaces such as
      slices where ranks/blocks data does not overlap in screen space this is the
      most efficient approach. However where ranks/blocks data have large amount
      of screen space overlap, this approach has high communication/compositing
      and overhead and a large amount of redundant computation that's discarded.
      The inplace-disjoint strategy was designed to address these issues. It
      leaves data inplace as much as possible but will assign pixels to ranks
      uniquely eliminating redundant computation. The communication costs are
      the same as the inplace strategy however they are split into two temporally
      disjoint parts with computation in between which tends to reduce congestion
      and contention. The balanced strategy divides the screen into equally sized
      disjoint regions and assigns each rank a region. This strategy can suffer
      from load balancing issues, and because no account is made of the initial
      data distribution it may have higher communication/compositing costs than
      the others. The parallel implementations have been tested with IceT in
      ParaView. The compositors uses non-blocking mpi communications, MPI
      subarrays for describing non-contoguous memory extents, and communicates
      efficiently by pasing mpi gpu mapped memory via extensions made to
      vtkPixelBufferObject. An object factory is used to override the serial
      objects with their parallel counterparts  when the parallel module is
      linked.
      
      * Contrast and Color Contrast Enhancement:
      The new contrast enhancement feature increases both dynamic range contrast
      while preserving patterns in the LIC. Contrast enhancment is implemented using
      histogram stretching. The color contrast enhancement is made in HSL space on
      the L channel to minimize color distortions. During the "enhanced" LIC mode
      contrast enhancement is also applied after the first pass of LIC compution.
      This helps strengthen streaking patterns.
      
      * Enhanced scalar color shading:
      A new mode has been added to the shader that shades surface geometry combining
      both LIC and scalar colors. The new shader produces bright colors without
      diminishing the visibility of the LIC by multiplying colored lit surface with
      computed LIC texture. The original blending implementation is left in place
      as it works well in many situations.
      
      * Noise texture customization:
      A new noise texture generator has been added to improve control over "streaking"
      in the convolved texture. The noise textures produced are fully customizable over
      9 degrees of freedom. [1] Noise distribution (Gaussian, Uniform, Perlin); [2] Noise
      texture size [3] Noise grain size [4,5] Min/max noise values [6] Number of noise
      levels; [7] Impulse noise probability; [8] Impulse noise background color; [9]
      Noise generator seed
      
      * Fragment masking controls:
      The new fragment masking provides controls over the color and intensity of masked
      fragments and their blending with scalars. Fragments are masked by threshold |V|<t,
      where t is a user specified threshold value, and V are mask vectors. Masking vectors
      can be optionally projected onto the surface or passed through un-modified so that
      threshold is provided in the original vector units and matches scalar color shading.
      
      * Vector Normalization Control:
      The new vector normalization control lets the user turn on and off normalization
      in the integrator. Disabling normalization can help highlight relative strengths
      in strongly varying regions of a flow field by making the amount of smoothing that
      occurs during convolution proportional to the flow strength.
      
      * Antialiasing:
      An optional anti-aliasing stage was added. In some cases the CE and EE stages
      produce streaks with sharp jagged transitions from black to white. The AA stage
      can be used to soften the result and smooth sharp transitions.
      
      * Optimizations:
      The implementation has been split into 8 major steps with the result of each stage
      cached in a texture.[1] Vector projection and lighting calculation; [2] Gather;
      [3] Compositingand guard pixel generation; [4] LIC Computation; [5] Scatter;
      [6] Scalar coloring; [7] Color contrast enhance; [8] Depth test. During user
      interaction stages that do not have modfied paramters or input data can be skiped
      using the cahced result instead.  This can save large amount of time for expensive
      operations such as projecting vectors, computing the LIC etc. Classes
      were added to simplify monitoring of various system paramters that would trigger
      an update, such as changes to lights, modelview or projection matrices, background
      color, etc. A new framebuffer object has been introduced, designed specifically
      for efficient buffer ping-pong, as well as efficiency improvements for setting
      shader unfiorms on inner parts of buffer ping-pong loops.
      
      * Porting and Testing:
      The code has been ported to Apple + ATI systems, and to OS Mesa with the gallium
      llvmpipe state tracker. A number of ctests have been introduced to excersize the
      new features. Parallel features have testing coverage in ParaView.
      
      Change-Id: I26f90a4e1e4e204289d38993d1e32fe5493b7a0d
      ad4dddfc