View Full Version : Very much a noob. Need some help

06-06-2006, 07:48 PM
To start, sorry this might be long. I'll get right to it.

I am trying to animate a fish approaching a hydroelctric dam. I am using an imported 3D CAD drawing for the dam. It took some doing, but it looks pretty good. The dam was created using state plane coordinates. Just in case you don't know what that is, it's like GPS, but uses feet from a central location, so my xyz might look like this: 195642 42150 725, instead of a GPS location in decimal degrees with an elevation. So the dam has been created in it's true to life location in space. This is because the data used to create the true to life fish tracks is also in state plane so the track will fit perfectly into the scene. Anyway, when I imported the dam, it is brought in in a way that I can't zoom in on it (it is very small). In order to get close to it I have to resize it. This really isn't a problem, but I just have a feeling that it is part of my problem further on.

I created my fish in Modeler, in the default coordinate system (which I think doesn't exist). I imported the data points of a fish track created in the field and connected the dots in Modeler to create a path for the fish to follow. Again, though, when I imported the track, it was very small and needed to be resized to fit with the dam.

I followed the directions in the path tutorial to make the fish follow the path. The fish has to be sized way way up now. It was created in true to life sizes, about 200mm. The dam and track have to be sized up so far that the grid can be as much as 5Mm. It should be, in real life, about 25-50m. This makes the fish several kilometers long. That's a big fish! This is where the problems begin.

1. The pivot point (not sure if that's what it's called) for the fish is quite a ways away from the fish itself. When I try and rotate it, it rotates around the pivot point in a big arc.

2. When I set up the fish to align to the path (curve constraint) it goes flying out of the scene because the pivot point is what gets aligned to the path.

3. The pivot point gets aligned to the "end" of the path, not the "start."

4. When the animation is played, the pivot point follows the path (backwards albeit) and the fish bounces around irratically way outside the scene.

The picture shows where the pivot point is in relation to the fish, which is on the right at the "start" of the track. (The picture is just to show my point. It looks much better when combined with Vue5 and the lighting is done right)


Again, sorry it's long, but if anyone can give me at least a place to start, I'd be forever greatful.

06-06-2006, 11:05 PM
The animation of an object is allways done around its pivot point. The pivot point lays per default in the center of the object (0,0,0). The body of your fish isn't modeled in the center, and there is your problem from.
One solution is to move the pivot point - in Layout there is a button "move pivot" beneath the move button.
Or you move the body of your fish to the center of the object by pressing F2 in modeler.
You will have to realign your fish to the path.

To the problem with your scale:
What was the way you imported you model so you couldn't zoom in? Do you know the "fit all" (a) button under the view menu?

06-06-2006, 11:35 PM
I've done the move pivot, but it still sends the fish way out of the scene when I align it to the path.

Because I created the dam in AutoCAD I had to do some round-a-bout things to get it to into Modeler. I think I used Accutrans, it's been a while. Even then, there were things missing that I had to recreate in Modeler. When it brought it in it was just very small to the point where even zoomed all the way in, it was still very small.

The only way I can find my model when I load it each sesssion is to "fit all," otherwise it's way off in space so I can't find it. I don't understand what that has to do with it's size.

I'll try your recentering with F2, but I think I've already tried it, but again I've tried so many things I don't know where I am anymore.

06-07-2006, 12:43 AM
I went through and realigned everything in Modeler and sent it to Layout. Everything lines up properly, sort of. The fish still snaps to the "end" of the track. When I play, the fish swims tail first from the "end" to the "start." If I play it in reverse it is absolutely perfect. I have tried aligning the each end of the track to the origin and both ways, the fish will always align to the "end" of the track. Any Ideas?

06-07-2006, 01:19 AM
sounds like your path needs reversing.
paths (or rather curves) have a "direction" just as polygons do.
One end of your curve will have a yellow circle around it when it is selected.
This is the nominal start point of the curve.
Select your path in modeller and hit the "f" key to flip it.
The circle should now be at the other end of the curve.
Take the path into layout and reattach the fish and it should now work.
Hope that helps.

06-07-2006, 10:15 AM
Of course it was just that easy to fix it's direction. I'm hoping the next bit is as easy. The fish still wants to swim tail first. How do I get it to swim head first?

06-07-2006, 10:32 AM
It might be worth rotating it in modeler and saving it out with the new orientation in place.

06-07-2006, 10:33 AM
Rotate it in Modeler 180 about the Y-Axis. The fish should look to Z+.

06-07-2006, 10:34 AM
I've been experimenting with the "Rotate pivot point" and it seems to be working. It looks like just a little bit of trial and error to get it set right. Now it seems like the fish doesn't align properly to the path. When the path goes up, I want the fish to swim up, meaning I want the path to always go into the mouth and come out the tail. Now it is just kind of going in and out of the sides.

06-07-2006, 10:35 AM
Thanks I posted the last one as you guys posted. I'll try it out.

06-07-2006, 10:46 AM
Fantastic, worked great. Thanks so much for the help. It's amazing how simple the fix is for something that can cause so much pain.