2D simple Shader reflection

mistouluf

See:
I very need to resolve this problem, if you have suggestion do not hesitate.

xyz

mistouluf It's not a bug. The shader is based on the screen texture, i.e. it uses pixels that were rendered on screen. It can't use pixels that went out of screen because those are not actually rendered. So it just repeats border pixels of the screen texture.

mistouluf

Okay, is there a workaround?

xyz

mistouluf Depends on what results you want to get.

mistouluf

I need it to reflect the entire area regardless of the y of the camera

mistouluf

backbuffercopy can help ?

xyz

mistouluf What do you mean by "entire area"?

mistouluf

From the reflection area, depends on the shader with scale_y which copies the image at the top

xyz

mistouluf Why just not make a copy of the entire image and scale it by -100% in y direction, without a shader.

mistouluf

imagine a player or a physical element being part of the effect, that would be better...

mistouluf

BackBufferCopy can copy either the entire screen or a region. If set to only a region (not the whole screen) and your shader uses pixels not in the region copied, the result of that read is undefined (most likely garbage from previous frames). In other words, it's possible to use BackBufferCopy to copy back a region of the screen and then read the screen texture from a different region.

xyz

mistouluf Not sure I understand what you mean. BackBufferCopy can still only access what's visible on the screen. You can't get pixels that were not rendered. If you need that, your best option is to setup a custom viewport and adjust its camera to render the complete area that's needed for the reflection and then read that viewport's framebuffer texture in the shader. In order for this to work, you'll have to calculate viewport's camera position depending of how much of the "water" is visible so it "sees" all the stuff that's not visible on the main screen but still visible in the reflection.

mistouluf

I don't understand, how to recover the texture of the viewport outside the camera?