Bug with Object transparency in overlays

[david1939]

I think I have encountered a bug in Motion Studio. I create fade-ins and fade-outs of objects by changing the transparency property, e.g. fade-in has the object's transparency initially set to 100%, set a key frame at the start of fade, set another one for the end of fade with transparency 0%. This works fine if an ordinary video file is being created. What I have noticed is that if I create an overlay file, then when I drop that file into VS (I'm using X4) in an overlay track, the resulting display shows that as soon as the transparency drops below 100% (i.e. 99% !) the object's outline appears with an opaque black fill; as the transparency setting drops, the surface details of the object appear. In other words, the object is not transparent at all except when the setting is exactly 100%.

Has anyone seen this effect? There are some work-arounds: if the background on the main video track is static, I can just make that the background in MS, create a video file and put it on the main track, but if the background is changing (series of images or a video), the work-arounds get complicated and labour-intensive. Then I suppose one just has to put up with a "black blip" at the beginning of a fade-in. For quick transitions it's not really noticeable (except to its creator!).

[Kingston]

Yes, I have seen that. My solution was to use a green screen background and export as a regular video, without an alpha channel. Then I used chroma key in the video editor.

[Kingston]

I believe we are suppose to use the Merge Control plug-in by adding it to the object, and keyframe the Merge Control's Transparency attribute instead. Anyway, that works the way we thought the object's transparency attribute was suppose to work when exporting as an overlay.

[david1939]

I just checked out the Merge plugin. Am I missing something here: it appears to be a global effect and you can't fade in and out objects independently.

Yes, I had forgotten the "green screen". That's what I used with my old version of Cool3D which came bundled with VS some versions ago. It only let you create video files. The trouble with the chroma approach was that sometimes the background scene's colour content was such that the overlay appeared partly transparent and the chroma adjustment level was quite tricky. I was very pleased to find the overlay option in MS!

[david1939]

I guess this topic is pretty well defunct now, but I have a question for the Moderators. We are discouraged from placing perceived "bugs" in the Wishlist, but is there a way of informing Corel of such things as this, which might properly be described as a "programming oversight", to be considered for correction in any forthcoming patch?

[Kingston]

This should be the place to submit English questions that don't require a service plan:
http://corel.force.com/index/KBCaseSubm ... ge?lang=en

BTW, I was able to get the effect by exporting two overlays. When I get the chance, I'll post back with my method.

Okay, I'm back with my method for fading out an object among other objects that don't fade out.

1. Start with two objects in the edit workspace, a cone and a cube. We want to fade out only the cone.

2. Move the Timeline Control Slider to frame 0.

3. Add the Merge Control plug-in in the Attributes panel. Set the Merge Control Transparency value to 0.

4. Move the Timeline Control Slider to the end of the animation, and set the Merge Control Transparency value to 100. This makes both objects fade out. Don't worry about the cube fading out as that will be overlayed later.

5. Export this animation to VideoStudio.

6. In VideoStudio, drag the clip down to Overlay Track 1. While you're at it, you might as well add a color clip to the main Video track for the background.

7. Back in MotionStudio 3D, select the cube in the Edit window, then hide the cube by clicking the Show/Hide icon on the Standard Toolbar.

8. Disable the Merge Control by clicking the corresponding Enable/Disable icon next to the thumbtack in the Timeline controls.

9. Export this animation to VideoStudio.

10. In VideoStudio, drag the clip to Overlay Track 2. You will need to add Overlay Track 2 with the Track Manager.

11. Click the Project button and then the Play button. The effect will be that the cone fades out but the cube doesn't.