zephyr707 Posted July 7, 2012 Share Posted July 7, 2012 Hello, I was trying to recreate something that I did in h11 in h12 and I couldn't do it. It involves putting an emissive piece of geo inside another one that has subsurface scattering. Kind of like a glowing object that shines through a translucent material. It workg in h11.1.67, but it doesn't appear to work in the various versions of h12 that I've tested (634 & 678). I'm wondering if I was exploiting a bug before that has been fixed or if this was broken in the transition? In the pictures you can clearly see the red emissive ball in the h11 version, but it just looks like the standard SSS occluded object in the h12 version. I've included the scene I used for the render and also another scene that I created entirely in h12 from scratch to isolate it to h12. Perhaps this isn't the best way to achieve what I am aiming for which is a glowing object under a surface like skin or some other organic material. The great disadvantage is that this gets burned into the SSS image plane and I haven't figured out a good way to export it correctly so I can tweak it in comp. Any help would be much appreciated as I'd rather work entirely in h12 rather than render certain things in the older version. h11_1_67_emission.hipnc h12_0_678_emission.hipnc many thanks in advance Quote Link to comment Share on other sites More sharing options...
theflu Posted July 7, 2012 Share Posted July 7, 2012 i ve also had some trouble with sss and refractions in h12... (mainly single scattering behind refractions..) Quote Link to comment Share on other sites More sharing options...
moondeer Posted July 7, 2012 Share Posted July 7, 2012 the SSS does not appear to use 'emissive' shaders. so i made an attempt with a geolight. also, light from within needs an inner surface, which i've also added. to test the penetration of the sss i have added a little window. lastly, to speed up the sss dev, i have tweaked the physicalsss2 node to activate 'optimize secondary rays'. your h11 'look' was not so much sss moving color from the inner to the outter as it was simple transparency. as you can see in my example, a true inner light does move color out, but in a very even diffused manner. i think you would rather see the sharp lines of the inner sphere. to accomplish this, i have set opacity to 90%. anyway, it was fun to play with SSS. cheers. h12_0_678_emission_new.hipnc.zip Quote Link to comment Share on other sites More sharing options...
zephyr707 Posted July 8, 2012 Author Share Posted July 8, 2012 thanks for your input gents. Eric, you are right about the color not moving out. i noticed this yesterday after I posted when I flippered up the images next to each other and did a diff. it does indeed look like the red circle is just slapped under there with no real bleed. I used this technique for a rushed project and it seemed like refractions were working, so i just assumed it was behaving correctly. Like you, i moved towards a geo light method and fumbled a bit with creating a usable inner surface that showed the shape of the geo light. My ultimate goal is to get this to look sort of like veins glowing inside an object and it seems that the farther the vein geo light is from the inner surface, the more diffuse it gets, which makes sense. I played around with some settings and got a nice result with decent definition of the curve and light bleeding out of the tube: and with 2 separate vein lights: the problem now is controlling the noise which seems to be crazy without high sampling rates. for example, using a polywired curve vs. just a nurbs curve for the geo light increased the noise dramatically. I'm looking through odforce trying to figure out how to optimize it and which rendering engine to use, seems to have changed a bit over the years what controls what most effectively... found some good posts though to read over. thanks for the help and the nice description + scene, i'll tak ea look at it now. if you know a good way to carve out a channel in geometry to place a curve in i'm all ears! thanks Quote Link to comment Share on other sites More sharing options...
moondeer Posted July 9, 2012 Share Posted July 9, 2012 this is simplistic, but it will give you some control over the curve while simultaneously carving a channel and creating a geo light from that same curve. carvechannel.hip.zip Quote Link to comment Share on other sites More sharing options...
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