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amm

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amm last won the day on December 1 2017

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    Anto
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  1. Distance from center in shops

    Well, then something else went wrong. From my small experience, it works....
  2. Distance from center in shops

    Should be something like in pic. That's SHOP, ''current'' space is camera.
  3. So here's attempt First of all, this is not an universal skin shader, exact replica or anything like that, I just tried to put some typical 'contemporary' methods into network. It is a mix of PBR Diffuse, PBR Single Scatter ( introduced in 16.5), and two PBR Reflections. It should showing what is possible to do, feel free to experiment with nodes inside shader network. There's just one subsurface scattering shader in mix. Houdini PBR Single Scatter has all map-able attributes, like scattering distance or attenuation color (while in old Mental Ray's Fast Skin, blurring radius is not) - things like exaggerated back scatter around ears or variances in attenuation color, are performed by simple trick: point color is used as mask for modulation. One SSS shader should be much faster to render than three, obviously. So at the end of the day, only typical Mental Ray's Fast Skin feature is screen blending of layers. I added switches between screen blend and plain additive. Important parameters: - Diffuse and SSS tint: that's 'modern' method, to multiply diffuse and SSS texture by complementary color, diffuse in light blue, SSS in orange. Overall is nearly the same as original color of texture, while complementary colors are there to get stronger diffuse - SSS difference. - Diffuse and SSS power: actually a gamma value, 1 is original, more than 1 is exaggerated darker color. - Diffuse and SSS Weights: for more of 'old paintings' style, feel free to raise the SSS weight. - Screen blending, Diffuse vs SSS, Reflections vs Diffuse and SSS: feel free to disable them just to see what happens. Nice side effect of screen blend is clumping of maximum direct lighting ( inside shader I set this to 1.25), making it easier to sample by Mantra. - Two reflections, first is wide, it acts more like additional diffuse shading. Second is sharp, intentionally disabled at edges. Bu some convention, shading model is set to Phong, as Phong does not fade the wide reflections (contrary to GGX) - so somehow Phong fits better, here. Any reflection parameter is a subject for tweaking, except maybe just one: in case of skin, it's always blueish tone, AFAIK that's natural effect of exaggerating the complementary reflection color in case of scattering media, something not automatically set by layered shading used in renderers like Mantra. Regarding wikihuman files, I've reduced resolution of bitmaps to make a smaller download, also I've used only three maps: diffuse color, specular color, and main displacement. Get files (around 30 Mb) there.
  4. I'd try to post Houdini scene this weekend, based on wikihuman files. Regarding Lee Perry's head, I'd say, enough is enough :).
  5. Hello McNistor, just a few thoughts: 'edge factor' in Mental Ray's fast skin (and default reflection falloff in all variances of MIA) could be a kind of very simplified Fresnel effect, precisely number 5 is exponent of dot product of shading normal and negated eye direction. In H, that could be 'normal falloff' node with mentioned exponent of 5 (or a bit more or less), plugged into 'fit range' node, where 'destination min' and 'destination max' are facing - edge weight, all that used to fade the reflection. That's simplified but gives a cleaner control over reflection weights than 'true' Fresnel. With unmodified 'fit range', it's zero at facing and one at edge. For subsurface shaders introduced in H 16 (honestly I don't know what is included in Principled thing), I'd definitively go to 16.5. Ones in 16 are utilizing indirect rays (while in 16.5 this switched back to direct) - so, I'm afraid, everything you'll be able to get with 16.0 versions, could be a long forum thread about long render times, fireflies and such. Unfortunately, there is no control over reflection color and face-edge weighting in H Skin shader, which makes it close-to-unusable. Why is that, I have no idea. PBR story should not be excuse for such brutal approach, IMO. IOR/Fresnel is present, but without precise facing/edge weighting control. Regarding Mental Ray's fast skin, 'subsurface' is actually based on wild approximations, it's baked diffuse shading to vertices and blurred later, that's why there's need for three layers. Anyway, author had a great artistic talent to get a good look out of all that. One important 'artistic' element is under 'advanced' tab, it is screen blending of layers, not plain additive, which helps to avoid 'burning' with strong lighting. That's in short. Last few months I've played a lot with this subject , basically I was able to get what I wanted. However, solution probably is not suitable for sharing all around. Anyway, it's possible to re-create a 'Master Zap's style' of shader components mixing in H. If anyone wants this, I'll be happy to help.
  6. Help With Speeding Up Render

    In case of glass, there's old trick utilized in some custom Mental Ray shaders, to distribute sampling, reflection *or* refraction, which on is more prominent for certain pixel. Worked well ten years ago, using machines of these times. Don't know what happens there, anyway result is really bad and unexpected. I've also tried your scene, tonight.
  7. Leaf Shader - How to get realistic translucency?

    Perhaps something like this. It is PBR Diffuse in translucency mode, 'shade both sides as front' is disabled. I think it should go as additive on top of some usual shader, as it seems it shades only opposite side of light. Alone is not enough.
  8. Smoothing Lighting in Material

    How about some light with soft shadows, that is, anything else than point or distant light. Another that comes in mind is blend based on luminance, instead of switch. Let's say 'fit' node with luminance as input, source max to something like 0.1, fit node as input of bias of color mix . Third option could be some subsurface shader (could be slower...) - some SSS shaders are based exactly on blurred diffuse shading, while I'm not sure does it apply to ones in Houdini. From my understanding, dealing with normals won't affect the terminator edge (that's old school name for edge between illuminated and no illuminated area). In case of lights with sharp shading and shadows, that's always sharp edge, while shading based on normal is able to smoothly fade the shading, down to zero on terminator edge - but not to change it.
  9. Space Suit

    Here is hiplc with complete ground with ground shader, I've cleaned scene a bit. For distribution of rocks, I think there are better methods described in tutorials around. I've used a sort of simple repeating by modulo to get multiple instances into positions of scattered points. Shader is somewhat special, I've tried to get as much bright 'dry' look, together with as much dark shadows from sun, typical for NASA photos of Mars. So finally there's mix of two PBR diffuse VOPs, one has faded front face to act as a 'dry reflection'. Mix is a bit modified screen blending of these two - instead of 'classic screen blending' where colors are subtracted from RGB 1, here's arbitrary value, I called it 'pedestal'. Effect is exaggerated brightness compared to standard diffuse shading, while color still can't go over 'pedestal' value, also bright parts are gradually blended to that max color, here it is some bright orange. Normally, someone will do such things in post. Doing that directly in render is a bit risky business - as it is for now, I'm not sure is it able to respond correctly to possible additional indirect light. Anyway it seems that Mantra is nicely resistant to such methods.
  10. Space Suit

    Thank You Yeah, ground is also Houdini, while there's nothing special there, IMO. Except instanced rocks, they are 'manual' work, it was just easier to get desired shape, still keeping as much low resolution, for around ten of initial instances. Perhaps only special part is small 'blending area' around each big rock, created by VDB combining, smoothing and deleting unwanted polygons. I believe that 'blending area' helped big rocks to fit to ground plane better, visually. Will see is there a way for as much generic mini-braids generation. For now it's based on (my own) system which generates really too much of guides in such case. Also has probably unnecessary loops, for syncing the along-length-distribution with arbitrary braid thickness, so on. In short, while it works, it's too slow and messy for going in public.
  11. Space Suit

    Hello I've started with this around H 16 release. Basically wanted to explore, to which level I'd be able to use procedural modeling when it comes to characters. So, "non procedural" part here belongs to another app, exactly Maya, where I've created a base body model, rig, posing - while Houdini part is hair of all sorts (hair, eyelashes, eyebrows..), also a lot of suit. Detailed map, what exactly belongs to which app is here. Let's say that 'harness system' is what I'm considering as most successful part. Later, started with Mantra renders, which turned out in kind of addiction - here are few of around hundred renders of this thing, I did in Mantra.
  12. Bird rig

    Thanks. Yeah that's something impossible to imagine by my Softimage - Maya mind. It seems they made me Cylon long time ago....
  13. Bird rig

    Forget me if I misunderstood, you mean 'diving' into bone node, or what. If so, that is giving some info about geometry, more or less in same way as Maya Shape node, but, not that much about transforms. By the way, in Houdini, things like Blend or Fetch Object, Look At Constraint , IK solver, they are behaving like parent, local transform is not affected. While in apps like Softimage or Maya, perhaps Blender too, "constrained transform" is firstly converted to local space of driven object, and modification is finally applied as blend-able override of local transform. In other words, if someone for example wants to read the local orientation of IK driven bone, this is immediately possible in mentioned apps. While in Houdini, this has to be calculated first, somehow, simple because ''local transform'' is not affected by some of mentioned "constraints" . As far as I know, one way is to use some specialized CHOP for that, another is optransform function. My vote for optransform, together with as much simple Houdini rig, because: - it allows to use SOP/VOP network, as imho only advantage against Maya or Blender when it comes to rigging. For any further deformation, distribution of instances, feathers or so. - Houdini kinematics is not so fast to evaluate, especially with a lot of CHOPs all around (to say politely). - it makes easier to replace the complete Houdini rig by animated hierarchy imported form another app, even in case when hierarchy does not match (because of global matrices and necessary re-construction of parent-child relationship).
  14. Bird rig

    I think the most versatile way is still a bunch optransform functions, with this you'll get global matrices into SOP/VOP network . You save the matrices as detail attribute, later you'll be able to deal with them in similar way as in Softimage ICE kinematics, as you know, inverse of one matrix multiplied by another, so on . For equivalent of Static Kine State probably you'll want to save a 'snapshot' of matrices into external bgeo file or something. So, 'Bone length' is a distance between bones. How to setup optransform function, I think you'll be able to find somewhere on forums, or download this thing from there (it could appear a little bit mangled in H 16, because of different working of Blend Object, but VOP structure should behave in same way). Few tips: Houdini bone uses a fixed rotation order, I think it's ZYX and Z is Local Rotation Axis. Whatever you're doing, take care of keeping the relative paths, to be able to create HDA, later. HDA creation seems to be allergic to too many linked parameters (or at least it still was in first public version of H 16), so, for a bit longer chain (parameter linked to already linked parameter), perhaps you'll want to build HDA first - while it's generally good idea to avoid any 'chain', if you can. For best evaluation, you'll want to have SOP/VOP network under the same hierarchy with your rig.
  15. Mesh Blend

    Thank you. I've uploaded to Orbolt .
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