View Full Version : Render Double Sided, but Single Sided in OpenGL.. possible?

01-22-2015, 11:17 PM
for objects such as high density trees with transparency/clip maps openGL slows down a great deal after adding a few of these. Not using transparency maps helps a lot, but unchecking double sided speeds things up a lot in openGL too!. Is there a way to have the 'double sided' box unchecked but also render a surface as double sided?

01-23-2015, 06:41 PM
This sounds like the beginning of a "Who's on first?"-type comedy sketch... "So unchecked 'double-sided' box..." "Right." "And then what?" "Check the 'double-sided' box."

I'm not sure I'm understanding what you want -- are you looking for a way to temporarily override the unchecked 'double-sided' box? Otherwise doesn't it control precisely what you want?

01-23-2015, 07:24 PM
Hey Jwiede thanks for the reply. Looks like I possibly didn't explain myself correctly, basically I noticed with 'multitexture shaders' there is a HUGE openGL speedup with 'double sided' is turned OFF in the surface editor. I mean the difference between light speed openGL navigation and slowing down to a crawl at an estimated 5-7 fps. Probably not noticeable for some LW users but add 1 or 2 high density trees @1.5mil polys each and you'll see what I mean. So.. I was hoping there was some way to have openGL ignore back faces without effecting the F9 render.

01-27-2015, 10:41 PM
Ideally it sounds like it should be a nodal property and hence be able to override the surface editor. That's how I sometimes use openGL to show certain textures (surface editor) yet render with others (nodal). Not sure if it would apply to double sided however? Worth an ask of the LW3dg folks .

01-30-2015, 02:49 AM
I tried playing around with the nodes but thus far haven't found a way to override any of the flags beneath the 'bump', ie: smoothing, smoothing threshold, double sided etc using nodes

01-30-2015, 07:21 AM
I had a large scene recently that would not return a reasonable frame rate when I hit play so I experimented and swapped the transparency channel setting from 'Sort by Object' to 'Alpha Clipping' which made a huge difference in OGL