i checked the tutorial (25 - Behind Effect.cpp ").
artifacts appears when i use the mode of RT_SINGLE_PASS or RT_SIMPLE. see screnshot.

This is D.depthTexture disabled/not supported yes?
I will fix this (disable RM_BEHIND) for the next release.

yes, one of my video cards does not support D.depthTexture. how can i determine this? i have two ways to display a player, when he is hidden:
1) if supported (and enabled) D.depthTexture -> RM_BEHIND.
2) if not supported (or disabled) D.depthTexture -> RM_BLEND for objects that hide the player.
i can only determine the state of D.depthTexture (true or false).
how to disable D.depthTexture (false), if the video card does not support it? i need it to use the second way.

if a card does not support RM_BEHIND then it will not be called at all (in the next release)
RM_BEHIND is always supported in RT_MULTI_PASS renderer