Thorsten > Im the last weeks, I've been working on integrating Lauri's skydome > scattering shader in a seamless way with the rest of the environment. I > have now a working version of the shaders available which could be > committed. > > This is: > > * the original skydome shader, with an added simulation of a low altitude > constant density haze layer and meaningful response to the parameters > /rendering/scene/overcast, /rendering/scene/scattering and > /rendering/scene/saturation. > > * a matching terrain shader which connects to the skydome in a (mostly) > seamless way > > * this can render everything from rather heavy fog on the ground to a near > space view at high altitude with (mostly) seamless transitions > > * some additional code getting the sunrise/sunset plausible by darkening > the haze where needed. See > > http://www.flightgear.org/forums/viewtopic.php?f=47&t=11274&start=135#p140 > 031 > > for some recent pictures > > * a small change in 3dclouds.frag to let clouds fade into a matching > horizon haze color. > > All this is conceptually independent of Local Weather - while it is > supported and the relevant parameters are automatically set by Local > Weather, they can be set from anywhere else. > > Now, I need some help. > > First, the combined effect of lots of 3d clouds and haze shading isn't > fast. It isn't really slow either, with multiple layers of 6/8 clouds > drawn to 45 km distance I still get ~20 fps out (36 without the haze and > skydome shader for the same clouds), but I have the feeling it could go > faster, there's too much redundant things happening. > > For instance, I get my altitude in model space by > > vec4 ep = gl_ModelViewMatrixInverse * vec4(0.0,0.0,0.0,1.0); > alt = ep.z; > > in the vertex shader - but this could probably easily be passed as a > uniform if I just would know how (lat, lon, alt) maps into model space. > And so on. So if anyone with more experience in shader writing can look > over it and smooth it a bit, that'd be very good. There is a writeup of > the underlying ideas available, and I have tried to comment a lot, and I > can also explain the underlying math. > > The second thing is - I can't get it into a distributable form myself. I > don't understand the structure of effect files. In my current > implementation, I have just overwritten the Flightgear defaults, used some > really ugly hack at one point and distributing that in this form means > either using my skydome/terrain or CPU rendering. I don't want to commit > it in such a form, this should be optionally linked to the scattering > shader on/off. Also, I run into other problems - I've tried to use the > haze shader instead of object default, but they're not blended to the same > final color when fully fogged, they come out too dark, and I don't know > why. I suspect that something happens to objects later that doesn't happen > to terrain... So, I'd need the help of someone who understands the effect > file structure to create a structure which can be committed without > wrecking everything else. > > If anyone is willing to help with either problem, please let me know and > then we can take the bulk of the technical discussion off list (where I > can use attachments). I have a pretty good idea what the issues are and in > what direction one should probably go to address them - I'm just a bit out > of my depth doing it myself. >
Looks like you are doing things the hard way. Emilian and I are busy rationalizing, and combining and improving shaders as appropriate right now: we would be happy to add your stuff to the pile. You could do a merger request to our sandbox here: https://gitorious.org/fgdata-textures-ng/fgdata-textures-ng Or post the files somewhere that we can get them, or email them as an attachment to me. I can't promise an instant solution, because we already have a heavy workload in FG and RL, but we can take a look. Vivian ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity and more. Splunk takes this data and makes sense of it. Business sense. IT sense. Common sense. http://p.sf.net/sfu/splunk-d2d-oct _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
