How to implement off-screen rendering?

[igorvlassov]

Hello,

I need to implement some sort of rendering server. On the current project phase I need to show texture with off-screen rendering. Do you have an idea how to implement this?

Regards,
Igor

[so0os]

Render to Texture, and copy pixels from it. search for dynamic texture examples on wiki, and read from it instead of write.

[igorvlassov]

I know how to render to texture. But how to disable rendering to the screen?

[so0os]

make RTT your viewport rendertarget instead of a renderwindow

[madmarx]

I think pure offscreen is not possible (at least not without providing your own context).

I mean, there are plenty of thread about off-screen rendering in Ogre, and all of them tell that rtt without the device (for directX) or without the context (for openGL) is not possible. Which means : no window => no DirectX and no OpenGL available.

http://www.ogre3d.org/forums/viewtopic. ... 80&start=0
https://www.ogre3d.org/forums/viewtopic ... 14&start=0

Maybe this can be of some help, if you are ok to use a hidden window :
http://www.ogre3d.org/forums/viewtopic.php?f=4&t=59441

Anyway, you can build a 1*1 window and then use it to manage your rtt then.

[igorvlassov]

Thanks so0os & madmarx,

seems, I simply will not create viewport for my off-screen scene and render it onto rtt only. I'll try to create another scene with plane "screen" & rtt texture on it & show it. This enough for my current proj.

[mrmclovin]

Does this mean I can't have a server app that isn't intended for rendering (hence no window) but uses a scene manager and scene nodes to hold position, scale and so on that it will send to the clients? I know that a scene manager might not be the most appropriate way to go, but it will save some dev time in my project!

[madmarx]

@mrmclovin

1/ I think there are things about this in the wiki. Eg:
http://www.ogre3d.org/tikiwiki/Loading+ ... e=Cookbook
http://www.ogre3d.org/tikiwiki/LoadingM ... e=Cookbook
...

2/ Don't forget that Ogre won't necessarily update the parts that are not visible in your animations (but you are aware of that of course ).

3/ Ogre is not designed to be used like that as far as I know, so If it saves you time, good. If you end up losing it, sorry, it's your fault .