Zoom Animation-Causes Shifting to Left-BUG?

[goddi]

Greetings,

I have seen this problem before but I could not figure out where it was coming from. But now I have found what is producing it.

The problem is that when I have selected Accelerate or Smooth of the Animation/Zoom, the image (the map in this example) will shift slightly to the left and then back to the right as it is doing the Zoom animation. It does not do this with Linear or Slow Down.

I have attached a PTE sample with just 2 slides. The second slide is a map that I have set to Zoom with Accelerate. The shift is more pronounced with Accelerate, but it also shows up with the Smooth setting.

Is this a bug? If not, how can I prevent these 'shifts'? I could increase the map's size beyond the 100% to help hide the shifting but I don't want to just mask the problem.

Thanks... Gary

ADDED LATER...and if you notice if you select Smooth, the map will, after shifting back to the right, makes a tiny shift back to the left at the end of the Zoom.

Tortuguero-Test Animation_Jul24-2012_11-35-47.zip

[Lin Evans]

Gary,

A long time ago I wrote a tutorial covering the necessity of setting pan, zoom and rotate to the same linearity or non-linearity. Your problems will be solved if you set all three to the same - in this case - accelerate.

Regardless of the logic - the probability is that there will nearly "always" be slight shifts from zero due to mouse cursor control, etc.,when you are setting parameters.

Set all three: Pan, Zoom and Rotate to Accelerate....

Best regards,

Lin

[davegee]

What Lin said.

DG

P.S. Why the keyframes on the Arrow - they don't do anything?

[fh1805]

Gary,

No that's not a bug; but it could be difficult to explain why not.

Think about what you are asking PTE to do. For the Zoom, you are not moving the centre point of the image, you are just expanding around that centre point. For the Pan, you are asking PTE to move the centre point to the left a fair amount and down slightly.

Now look at the point of key interest in your image. It's the end of the arrow, right? That's fairly tight over to the right hand side. So, if you pan the image to the left before the zoom has chance to develop, you will inevitably move the image off screen a little and reveal some of the default background.

To achieve the result that you want, I would delete the ending keyframe on the map, change the Auto to 50% on the toolbar of the O&A window, create a new ending keyframe and then set its values by holding down the shift key while you click and drag on the lower left corner of the map. This has the effect of anchoring the map at its top left corner. That will give you a pan and zoom that shows the map as you want it. You can then tune either or both away from the standard Linear option if you want to.

regards,

Peter

[goddi]

Gary,

A long time ago I wrote a tutorial covering the necessity of setting pan, zoom and rotate to the same linearity or non-linearity. Your problems will be solved if you set all three to the same - in this case - accelerate.

Regardless of the logic - the probability is that there will nearly "always" be slight shifts from zero due to mouse cursor control, etc.,when you are setting parameters.

Set all three: Pan, Zoom and Rotate to Accelerate....

Best regards,

Lin

==================

Greetings Lin,

Well, I must have missed that tutorial. I have noticed this funny movement problem for many years. I always thought it was something I was inputting. Thanks for the tip. I tried it (setting Pan, Zoom and Rotate to the same linearity setting) and it stopped the shifting. This is a pretty strange effect and seems to be a 'bug' because who would have thought that this is the way to 'fix' the problem? It must be a technical hurdle to fix, but thanks for the work-around.

Gary

[Lin Evans]

Hi Gary,

It's not a bug. You were asking PTE to perform a zoom at one rate of change while performing a pan at another. The net result is to "shift" the position viz the observer at various points along the timeline. Even though it's not always "necessary" to set all three parameters to the same rate of change, there is no "penalty" for doing so and it obviates the potential for issues such as you experienced. There are times when one might want these types of non linear behaviors, but generally just setting all three parameters to the identical setting will result in one's expectations being met.

Best regards,

Lin

[goddi]

What Lin said.

DG

P.S. Why the keyframes on the Arrow - they don't do anything?

Dave,

I was in the middle of making the arrow to have an Opacity of zero at the beginning and going to 100% midway. I just was not finished with it and eventually will be 'fixed'.

Work in progress....

Gary

[davegee]

Gary,

Read carefully what Peter has said.

You are asking it to move to the left and down at a faster rate than you are asking it to zoom.

Remove the zoom parameters and see what happens in the mini viewer.

Then in the end key frame add the zoom back in.

The map has (effectively) moved to the left and down and then zoomed in - but at different rates.

For the first half of the movement the Pan is moving quicker than the zoom - second half, vice versa.

It's not a bug.

DG

[goddi]

Gary,

No that's not a bug; but it could be difficult to explain why not....

regards,

Peter

======================

Peter,

The reason I would call it a 'bug' is that the shifting does not occur if you select the Linear or the Slow Down settings, but it does in the other two options. Lin has the easy 'solution'. I just don't think users should be jumping through hoops to stop the Zoom from doing strange things with non-intuitive steps. Your steps might be a remedy but I don't want to get too complicated when trying to do a simple Zoom.

Thanks... Gary

[Lin Evans]

Hi Gary,

Keep this in mind. When you set multiple parameters (zoom, pan and/or rotate) you "must" set the parameters to the identical rate of change (linear, accelerate, slow down, smooth) to avoid unanticipated results.

It's not a bug with PTE, it's just complex logic. As Peter explained - you are asking the program to perform at differing rates of change. The reason there is no shift with linear is because it is the "default" and all parameters are defaulted to the same rate of change. Whenever you change one of these parameters and others are active and not changed, you will see a "shift" in position at various points along the timeline. This is inevitable and the logical result of linear versus non-linear interactions.

If you think about it for a bit and work through the logic it will become apparent.

Best regards,

Lin

[davegee]

======================

............the shifting does not occur if you select the Linear or the Slow Down settings,........

Look again!

If you choose Slow Down instead of Accelerate the the map moves to the right instead of moving to the left but does not go "off screen".

DG

[goddi]

Gary,

Read carefully what Peter has said.

You are asking it to move to the left and down at a faster rate than you are asking it to zoom.

Remove the zoom parameters and see what happens in the mini viewer.

Then in the end key frame add the zoom back in.

The map has (effectively) moved to the left and down and then zoomed in - but at different rates.

For the first half of the movement the Pan is moving quicker than the zoom - second half, vice versa.

It's not a bug.

DG

========================

Dave and Lin,

I am better understanding what is happening, now. When I did the Zoom, I used the Zoom's up/down arrows to set the initial Zoom parameter. However, when I 'moved' the map to reposition it after setting the Zoom, I just clicked and dragged the map over to where I wanted it to end up. I wasn't thinking that I was actually 'Panning' the map over to that position. So I now understand the Pan/Zoom movement explanation and see it is the combination of the two.

Maybe there is a good reason for being able to select different settings for Pan, Zoom and Rotate a keyframe, but why is it not the default to have Pan, Zoom and Rotate automatically retain the same setting (with the option to undo the default), and then allow the user to be able to be override the default, if that is what one wishes? For example, if one choose Slow Down for either Pan, Zoom or Rotate, they would all change to that setting. This would avoid these 'shifting' problem without having to understand the non-intuitive way to avoid it, but allow for the flexibility that in now has.

Thanks...

Gary

[Lin Evans]

Hi Gary,

That might make a good suggestion - why not post it in the suggestion forum...

Best regards,

Lin

[fh1805]

Maybe there is a good reason for being able to select different settings for Pan, Zoom and Rotate a keyframe... For example, if one choose Slow Down for either Pan, Zoom or Rotate, they would all change to that setting. This would avoid these 'shifting' problem without having to understand the non-intuitive way to avoid it, but allow for the flexibility that in now has.

Gary,

If they all change when one changes then you have destroyed the flexibility. Flexibility is the "good reason" why it works the way that it does.

Peter

[goddi]

Hi Gary,

That might make a good suggestion - why not post it in the suggestion forum...

Best regards,

Lin

======================

Lin,

Ok...I did not know if my idea would float or not. Just because it makes sense to me does not mean it would be a good idea. I'll give it a try in the Suggestions forum. It seems to have passed your 'sniff' test.

Thanks... Gary

[Lin Evans]

Hi Gary,

As long as there were the "option" to go back to the way it is now for flexibility, I see no real issue with having all defaulted to whatever you choose. The question has been asked in the past about auto setting of "glue" "separate" at keyframes to avoid having to manually change for multiple keyframes on multiple objects, but so far there has been no explanation as to why the default is as it is. Perhaps there are programming issues which make it difficult - I don't know because I don't program in Pascal.

Best regards,

Lin

[goddi]

Gary,

If they all change when one changes then you have destroyed the flexibility. Flexibility is the "good reason" why it works the way that it does.

Peter

======================

Peter,

I am not suggesting to not keep the current flexibility. What I am suggesting is that the 'default' should be that when you select one of the settings (Linear, etc.) for a particular keyframe, then the settings would automatically change for all three (Pan, Zoom and Rotate). This would remove the possibility for the 'shift' problem to occur. Lin's solution to set all three animations to the same setting to avoid the 'shift' problem works. I am just suggesting to make this action to be the 'default'.

Who would know you needed to do this unless someone told them? But I also said that there should be a way to override this default for those who wanted to retain the flexibility of the current menu's structure. It seems to me that most people would want the results from having all three settings to be set to the same choice as the default. All that has to be done is to have them linked so that a change in one will change the other two. And also have the ability to unlink them to get back the current 'flexibility'. Doesn't this make sense?

Gary