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使Alpha通道/不透明度用于照明

[英]Getting alpha channel/opacity working for lighting

原文 2013-11-01 21:26:48 2 1 java/ opacity/ lighting/ alpha-transparency

I have two pixel arrays, foreground and lighting. 我有两个像素阵列，前景和照明。 When I draw a white radial gradient (blurry circle) onto the lighting array, I want it to make the foreground visible - much like a torch in terraria/starbound. 当我在照明阵列上绘制一个白色的径向渐变（模糊圆圈）时，我希望它使前景可见-就像terraria / starbound中的火炬一样。 However, I also want to be able to mix different colors of lighting, rather than be stuck with black to white. 但是，我也希望能够混合使用不同颜色的照明，而不是将其卡在黑与白之间。

So how do I manipulate the pixel arrays so that they 'multiply' (I believe it's called)? 那么，如何操作像素阵列，使其“相乘”（我相信它被称为）？ Or is there an easier way using RGBA which I have not been able to get to work (flickering black on white or image getting ever more posterized)? 还是有没有一种更容易使用RGBA的方法，而我却无法使用它（白色的黑色闪烁或图像变得更加海报化）？

So far most responses regarding alpha channels / opacity have been using libraries from java which for this project I want to refrain from using. 到目前为止，有关alpha通道/不透明度的大多数响应都使用了Java中的库，对于该项目，我想避免使用。

Any help much appreciated! 任何帮助，不胜感激！

1 个解决方案

If you want to know how the blending modes (such as "multiply") work in image editing programs on the pixel-value level, read this: How does photoshop blend two images together? 如果您想知道混合模式（例如“乘”）在像素值级别的图像编辑程序中如何工作，请阅读以下内容： photoshop如何将两个图像混合在一起？ . 。

Note that if you want to make the image lighter, you need a mode like "screen", because "multiply" makes it darker. 请注意，如果要使图像更亮，则需要“屏幕”之类的模式，因为“相乘”会使图像更暗。