Render into Texture

[Andru]

I want to share with you some interesting fact about rendering into texture in different engines/libraries/etc., and I want to test some of them, which are you using(Andorra2D, Asphyre, Phoenix, whatever else, except ZenGL and quad-engine, because I know how they works ).

So, here the only needed resource:


Here the step-by-step operations for reproducing "interesting" effect:
- create window with size 256x256
- create and set current Render Target, which must be absolutely transparent(color - 0, alpha - 0)
- render white rectangle with size 256x256 and alpha equal to 255
- render penguin(size - 64x64) in coordinates 96, 96(or just in center - 128,128 ) with normal blending
- switch to scene
- render content of Render Target using normal blending mode

At the end you must get something like this:


Attach your screen here and describe which engine did you use. Most of engines(I think so) will show you little bit grey penguin instead of "cute and white" Like this:

[Darthman]

Sorry but I can't stand and not to post in this thread.
This interesting bug, Andru mentioned above, is really like second picture. Gray penguin (OMFG). I add from myself, that if rendertarget will be transparent and non black (green for example), then penguin will be green too(ZOMGF)!
So Andru knew, but I anyway post my result after modification of sourcecode to avoid this "effect" (thanks Andru for idea):

[User137]

You propably mean of what happens when rendering a transparent image to uninitialized rendertarget?

Haven't added FBO or RenderBuffer to Next3D yet but *note to self*: Use this when time comes http://www.songho.ca/opengl/gl_fbo.html

[Andru]

You propably mean of what happens when rendering a transparent image to uninitialized rendertarget?

Nope... this "problem" with uninitialized rendertarget is for children

http://www.songho.ca/opengl/gl_fbo.html

Here is no solution for problem above.

[User137]

Here is no solution for problem above.

No but maybe solution to problem of how to render into texture

[Dan]

Looks perfectly fine here (Gen2)

[Murmandamus]

Could it potentially a lighting issue? In other words, "neutral" illumination vs "full bright"?

Just venturing a guess...

[Andru]

Could it potentially a lighting issue? In other words, "neutral" illumination vs "full bright"?

If this reason was, then picture would be much worse

Dan
Thanks for the test. But you have some trouble with brightness of penguin...

Seems nobody else wants to help me with testing engines, so I will try to investigate engines myself )

About the "problem". For some reason this is not obvious for other developers, and they forget about Separate Blend, when they render into texture.

[Traveler]

To be fair, one day is too short a time to request feedback from different engines. Also, I think the amount of engines used nowadays is minimal. I wonder how many people, not counting their creators, are using them.

[Darthman]

Seems ur penguin, Dan, is quite brighter than it must be.