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Alpha channel texture problem
I’ve got a string of moving arrows with a material that has an alpha channel so that the color of the arrows will fade to invisibility when they reach a certain point. So, I have a material with a color channel and an alpha channel. It is mapped onto the arrows in flat mode, no tiling, rotated P=90 so that it’s in the X-Z plane. This works great, the arrows are yellow til they get to where the alpha begins and then they go invisible. I’m using a black/white gradient in the alpha channel.
The problem is that I want to change the color channel from yellow to orange over a four second interval. When I do this the alpha channel no longer works, and where it should be invisible it becomes black instead. I’ve tried this two different ways:
1. I duplicated the yellow material that had the alpha channel and changed only the color to orange, then animated a material change. The two materials that changed should have been identical except for the color, and it works until the material is changed completely over then it snaps to black where the alpha should make it invisible.
2. I tried using only one material and animating the color change in the color channel from yellow to orange, leaving the alpha alone. Again, it works until it gets to the second keyframe, then snaps to black where it should be invisible.
I can’t figure out why the alpha channel becomes inactive after the color change. Anyone have any ideas about this?
thanks,
Jack -
2 Replies
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Sounds to me like the alpha is running out at the end of the UV space you defined for the flat mapping … since you set the texture not to tile. I can’t think why the animation in the color channel would have any effect.
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I used Fit to Region to map the texture onto the stream of arrows (I have two other textures covering different areas also. I don’t think that’s causing a problem, and the texture grid seems to cover everything. It’s weird. But here’s something – I may have solved the problem (well, I say “solved,” but I still don’t really know what actually caused it). I’ve been using Make Preview to preview little slices of animation to make sure everything was working, and had the anti-aliasing set to None. I went in and set it to Geometry, and it seems to be working correctly now. Strange problem.
Jack
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