3D Graphics Performance Comparison – Part 3 (SpaceClaim)

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Next up is the SpaceClaim 2010, the CAD system on which I previously bestowed the title “Freaking Awesome” with regard to graphics performance. SpaceClaim co-founder Blake Courter tells me that I needed to adjust only a couple of graphics settings to “make SpaceClaim the fastest“.

He told me to set rendering quality to 3 and turn anti-aliasing off. As it turns out, these are the default settings. So SpaceClaim has its graphics settings optimized for large models by default, unlike some other CAD systems I’ve seen. Let’s see what kind of display quality we get for these default settings.

Click image for larger view

You will need to click the image and zoom to actual size to appreciate it. I absolutely love this. First off, if the imported model does not have color information, SpaceClaim automatically colors parts differently using a dull color scheme that does not hit the eye. This makes it easy to work with as opposed to having a couple of hundred parts all colored in a dull gray like in SolidWorks or Inventor or bright green like KeyCreator. Secondly, the specular reflection is very subtle, almost non-existent. It looks almost like a flat shaded model which is what I absolutely love. Too much of realism and strong reflections distract me as I go to pick faces, edges and vertices to perform modeling operations. The shininess is just enough to highlight curved surfaces so that my brain can easily wrap itself around the model, but not too much jazz that it starts to get confused.

There was no need to create another video since the one from the original comparison one would do. But in this series I intend to do the navigation in the CAD systems in the exact same manner – orbit around the model about the Z axis, first slowly and then fast. So here goes.

Like I said, Freaking Awesome!!

Part 4 >>

  • Ken

    Looking at the image you posted from SpaceClaim, I noticed some display descrepancies with regards to horizon edges of many of the cylindrical portions. Namely, the horizon edges are plain missing! If you look at the starter, it is blatantly obvious that they are missing, and as you look around closely, you will notice them missing from many of the cylindrical surfaces. Could this be why they are so fast… just leave some of the edges out?

  • Ken

    It appears that the image from MoI is also missing horizon lines. Heck maybe they all lose them. I just happened to notice the image from SpaceClaim looked funny because it looked like portions were just missing.

  • Ken – is that an artifact of ACIS underpinning SpaceClaim (can't speak for MoI) and it not splitting cylinders into two halves (as Parasolid often does) or something in the translation/STEP reading process?

  • Ken

    I think it is a display option. I checked on SE also and the “silhouette” (horizon) lines are not displayed on rotation, but there is an option to display them on a static view.

  • Graphics enthusiast

    MoI does not support horizon/silhouette lines and does a really horrid job around sharp corners (e.g., the back-facing lines bleed through the front). MoI also seems to only be able to display the seam of (self-created) periodic surfaces.

  • Kevin Schneider

    Silhouette lines are calculated by the graphics system. they are not real edges. They can take two passes to calculate so they are a performance hit and most applications don't show them or offer options to disable them.

  • Actually, I messed up. You get even faster graphics if you set the rendering quality to 1. That's the way to get the fastest graphics out of SpaceClaim. I cannot claim that it will make SpaceClaim faster than any other 3D system. Looking forward to seeing your results.

    As for silhouette edges, we don't display them in shaded mode. I'm not aware of that being something customers have asked for. We do show them in hidden line mode, and you can project them to sketches from the Project tool.

    Thanks,
    -Blake

  • I believe the bleeding thing you mention is an effect in MoI and done on purpose. I believe it looks nice on small and simple objects, but can be confusing in large complex models like this one.

  • Silhouette edges are not real edges but can be useful when showing something like a sphere, which is a face that has only one edge. Different CAD systems show or display them in different situations. They are meant to aid in visualization, not in modeling. I mean you cannot pick silhouette edges.

  • Michael Gibson

    > and does a really horrid job around sharp
    > corners (e.g., the back-facing lines bleed
    > through the front).

    Yeah that is something I want to tune up in the future to not pull backfacing edges with as much zbias as other edges.

    Right now it pulls all edges forward in depth by a fair amount to make sure they don't get hidden by the surfaces.

    It's a pretty minor issue though.

    > MoI also seems to only be able to display
    > the seam of (self-created) periodic surfaces.

    This is incorrect – MoI will show the seam edge of any closed surface, no matter if it is created by MoI or imported or whatever. The seam edge is just treated the same as any other edge for display purposes.

  • Blake,

    Yes, setting rendering quality to 1 (lowest) speeds up things even further, but results in a very coarse mesh (see http://bit.ly/a9mvRn). With rendering quality set to 3 (default) the mesh is quite good (see http://bit.ly/b9jLUh). I think 3 is a good level. I don't think users will want to work with 1.

  • BTW, this comparison is not just about speed. It's about quality as well. Otherwise I could set up all CAD systems in such a way that spheres look like cubes.

  • Ken

    I realize they are not “real” edges, but they do come in very handy when looking at a shaded model where adjacent parts/features might be shaded similarly to determine where one ends and the other begins. And you can reference and project silhouette edges when sketching, this is essential to all mechanical modelers.

  • Ken

    That would be an interesting comparison… See which system can render the worse looking model!

  • Graphics enthusiast

    I did not mean to imply that the seams only display on MoI created objects – what I was trying to say was the MoI displays only seams and no silhouettes. Silhouette display would allow MoI to generate technical illustration style displays which IMO would greatly enhance your product.

  • Michael Gibson

    Yeah currently MoI does not display silhouettes dynamically, but there is actually a command that will generate the silhouettes as regular curve objects which can then be exported for making a technical illustration.

    See here for an example:
    http://moi3d.com/forum/index.php?webtag=MOI&msg

    I do want to improve that in the future to be a more full hidden line with silhouettes export to illustration formats.

    That kind of vector output of silhouettes seems to be more important to illustrators than having it as part of the realtime display but that could be nice too at some point.