[Paraview-developers] [EXTERNAL] Re: Remind me - AA

[Utkarsh Ayachit]

While the technical arguments are indeed sound, we tend to get asked
about this quite periodically. What do folks think about using AA by
default for builtin or client-side render and not when compositing?
This way, 2D charts, for example, will always have AA turned on --
just a nice little perk.

Utkarsh

On Tue, Jul 5, 2016 at 10:08 PM, Scott, W Alan <wascott at sandia.gov> wrote:
> OK, much better pushback.  I would say AA (either the hack mentioned below
> or real) probably isn’t worth a non-trivial software change at this point.
> We should keep it on the table for future work.
>
>
>
> Alan
>
>
>
> From: Moreland, Kenneth
> Sent: Friday, July 01, 2016 7:58 PM
>
>
> To: Scott, W Alan <wascott at sandia.gov>; David E DeMarle
> <dave.demarle at kitware.com>
> Cc: paraview-developers at paraview.org
> Subject: Re: [Paraview-developers] [EXTERNAL] Re: Remind me - AA
>
>
>
> OK, let me rephrase my pushback. There are several technical hurtles to
> implement this feature. We know how to achive this effect, but it requires a
> non-trivial change to the rendering system that will take significant
> development cycles, add complexity to the rendering system, and potentially
> destabilize several features relying on the rendering. Plus, this is all
> happening in the middle of a push for other (more important) rendering
> features (OpenGL2, OpenSWR, Ospray, IndeX).
>
>
>
> We turned off antialiasing in ParaView years ago because it caused way more
> problems than it was worth. The question is, do you really think it is
> important enough now to have a software push for it?
>
>
>
> -Ken
>
>
>
> From: Walter Scott <wascott at sandia.gov>
> Date: Friday, July 1, 2016 at 12:12 PM
> To: Kenneth Moreland <kmorel at sandia.gov>, David E DeMarle
> <dave.demarle at kitware.com>
> Cc: "paraview-developers at paraview.org" <paraview-developers at paraview.org>
> Subject: RE: [Paraview-developers] [EXTERNAL] Re: Remind me - AA
>
>
>
> Makes sense.  But…
>
>
>
> 1)      Make it 2X – i.e., 4 times the pixels, if the user asks for better
> images when lines are visible.  Default off.  You want better images, it
> will be slower (when lines are visible).
>
> 2)      We do it (when rendering off screen) all the time when making movies
> for the power wall.  I don’t see this as an issue…
>
> 3)      Have the line widths automatically written 2X requested width.
> Thus, when it shrinks by 2, you get normal, poor man’s AA lines.
>
>
>
> Alan
>
>
>
> From: Moreland, Kenneth
> Sent: Friday, July 01, 2016 9:20 AM
> To: Scott, W Alan <wascott at sandia.gov>; David E DeMarle
> <dave.demarle at kitware.com>
> Cc: paraview-developers at paraview.org
> Subject: Re: [Paraview-developers] [EXTERNAL] Re: Remind me - AA
>
>
>
> Reason 1: Increasing the resolution 2X increases the compositing overhead by
> up to 4. Increasing the resolution 4X increases the compositing time by up
> to 16. It can be a noticeable difference when rendering interactively.
>
>
>
> Reason 2: There can be technical difficulties in rendering images that
> large. You are likely to have a rendering context of the original
> resolution. To render such large images with images/movies, it renders image
> tiles and stitches them together. This adds further overhead and
> complication in rendering.
>
>
>
> Reason 3: Line width is measured in pixels. Changing the resolution of the
> image in this way will change the perceived line width.
>
>
>
> -Ken
>
>
>
> From: Paraview-developers <paraview-developers-bounces at paraview.org> on
> behalf of Walter Scott <wascott at sandia.gov>
> Date: Thursday, June 30, 2016 at 7:48 PM
> To: David E DeMarle <dave.demarle at kitware.com>
> Cc: "paraview-developers at paraview.org" <paraview-developers at paraview.org>
> Subject: Re: [Paraview-developers] [EXTERNAL] Re: Remind me - AA
>
>
>
> OK, why can’t we do that?  Have a mode that internally runs 2X or 4X
> resolution, does the compositing, and then shrinks back to what the user
> wants?  Only turn it on when 3d lines are in the image?
>
>
>
>
>
>
>
> From: David E DeMarle [mailto:dave.demarle at kitware.com]
> Sent: Thursday, June 30, 2016 7:46 PM
> To: Scott, W Alan <wascott at sandia.gov>
> Cc: paraview-developers at paraview.org
> Subject: [EXTERNAL] Re: [Paraview-developers] Remind me - AA
>
>
>
>
> Antialiasing confuses depth compositing.
>
> Better to save out images/movies at 4x resolution and resample outside of
> paraview.
>
>
> On Thursday, June 30, 2016, Scott, W Alan <wascott at sandia.gov> wrote:
>
> Why can’t we turn anti alias lines on?  I am doing a feature edges, and it
> looks horrible.
>
>
>
> Thanks,
>
>
>
> Alan
>
>
>
> --------------------------------------------------------
>
> W. Alan Scott
>
> ParaView Support Manager
>
>
>
> SAIC
>
> Sandia National Laboratories, MS 0822
>
> Org 9326 - Building 880 A1-K
>
> (505) 284-0932   FAX (505) 284-5619
>
> ---------------------------------------------------------
>
>
>
>
>
> --
> David E DeMarle
> Kitware, Inc.
> R&D Engineer
> 21 Corporate Drive
> Clifton Park, NY 12065-8662
> Phone: 518-881-4909
>
>
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