This might be common knowledge to developers from a design background or those who have worked with texture/image sheets in the past, but I think it’s useful to mention an important technique to those not as familiar with converting their previous “one-image-per-file” art over to image sheets with Corona’s recent “imageSheet” API…
Basically, if you’re placing a bunch of textures with solid/colored backgrounds *directly* next to each other on the texture sheet, you should try (if possible) to space them out and pad them with a few pixels of transparent space. I refer to when you’re placing image material directly touching the neighboring “frame” at the pixel level, and those frames have different colored backgrounds. For example…
Frame 1 is a “blue sky” image with a puffy white cloud in the middle. Frame 2 is a “sunset sky” image, with a bright orange background and a yellow sun in the middle… it is placed directly to the right of the blue sky image on your image sheet. In your app, you might see a slight “bleed” of the orange sky color onto the “blue sky” image when you display it. This bleed will be a mere hairline, but it flickers a bit and it’s definitely noticeable.
I’m not sure if this is a Corona issue or if it’s common to all SDKs; I’m not claiming that it’s a “bug”. I’m just mentioning it as a precaution to those currently converting their apps to use image sheets. It occurs at various resolutions, even at 1:1 ratio (i.e. your config is 768x1024 and you’re designing only for iPad which is that same resolution).
The solution to this, as I say above, is to pad the frames with a few pixels of transparent space, even if this makes your overall image sheet a bit larger. Or, arrange your frames so you don’t have different colors packed in right next to each other.
Hopefully this tip is useful to some!
Brent Sorrentino
Ignis Design [import]uid: 9747 topic_id: 23561 reply_id: 323561[/import]
