[Bf-committers] Blender success story, a couple of potential
bugs and a feature request.
Jonathan Merritt
bf-committers@blender.org
Mon, 24 Nov 2003 15:26:58 +1100
Forgot to mention...
I'm using the current CVS version of Blender, running on a customized
Intel Linux system, but with very recent versions (< 3 months since last
update from source) of all of the dependencies.
> Hi Everyone,
>
> I recently put Blender to use on an animation that was shown at
> Equitana, which is a big commercial horse show that was held here in
> Melbourne over the last weekend. I gave Blender a big plug, pointing
> out that the animation would not have been possible without the
> efforts of Free Software programmers all over the world. Here's a
> single frame:
> http://www.warpax.com/temp/forelimb-frame.png
> The animation showed a moving horse limb (animated with real
> kinematics data that I pulled out of a refereed publication), and
> illustrated the function of one of the ligaments of the limb in
> storing elastic energy. I'm reluctant to post the full animation at
> this stage, since there are a few things that need to be fixed, and
> among them are the bugs listed below.
>
> The limb is an animated armature (animated by rotation and location
> keyframes, not by an IK solver). It has a basic animation that is set
> to repeat by having a cyclic extend mode. In order to control the
> speed of the animation, the armature object has a Time IPO curve,
> whose slope varies through the animation to slow the limb down for a
> while before moving it back up to full speed.
>
> I discovered that the rendering of objects parented by the "Use
> Armature" method seems to have a bug after the first frame, when
> motion blur is used. The following is an example:
> http://www.warpax.com/temp/forelimb-ghost.png
> Here, the ligament at the back of the bones is rendered in entirely
> the wrong place for just *one* of the motion blur frames (the others
> may be out of place as well, but I can't tell). Note that this bug
> *does not* show up in the *first* rendered frame, only in subsequent
> frames, and does not appear in Blender itself when an animation is
> played using Alt-AKEY. Hence, you can't observe the bug by rendering
> a single frame - it will only appear in the second frame of a rendered
> animation.
>
> Also, the amount of blur applied to the animation does not seem to
> respect the relative progression of time indicated by the Time IPO
> curve. Hence, even when I slowed the Time IPO curve to a complete
> halt (ie: horizontal line in the IPO window), the rendered objects
> were still being motion-blurred. Is this the desired behaviour?
>
> Finally, an option to render a flat mirror reflection map (as opposed
> to a cube-face environment map) would be really wonderful. In this
> instance, with a heavily set-up scene, I was able to reflect things
> manually only by painstakingly selecting everything except the bone
> mesh objects and reflecting them in the ground plane. This was quite
> a hassle, considering the simplicity of the effect from a technical
> point of view.
>
> Jonathan Merritt.
> PhD Student in Equine Biomechanics,
> Faculty of Veterinary Science,
> The University of Melbourne.
>
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