hatrick Posted March 17, 2009 Share Posted March 17, 2009 I posted some detailed questions about my current work in this forum and got some very usefull informtion... although i have common problems with lightning and materials. Hopefully you have some time for a beginner. Here are some issues i stuck with: My first step was to setup an environment light with an HDRI map. Further i created a white softbox around the model to make it overall brigther. That caused a very diffuse look to my reflective materials. Somehow i cant use the lightlinkerpane the right way to exlude the white surface of the box from my reflection. Another try was to link the HDR map only to my reflections in the material propertys .... without success. may you can give me some common recommendations how to light and shade such a scene propperly here is a pic and the hipfile... thx a lot impala_pokal_v2.hipnc Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 17, 2009 Author Share Posted March 17, 2009 .... what kind of info do you need ? just a little help would be great please guys Quote Link to comment Share on other sites More sharing options...
ihab Posted March 17, 2009 Share Posted March 17, 2009 I posted some detailed questions about my current work in this forum and got some very usefull informtion...although i have common problems with lightning and materials. Hopefully you have some time for a beginner. Here are some issues i stuck with: My first step was to setup an environment light with an HDRI map. Further i created a white softbox around the model to make it overall brigther. That caused a very diffuse look to my reflective materials. Somehow i cant use the lightlinkerpane the right way to exlude the white surface of the box from my reflection. Another try was to link the HDR map only to my reflections in the material propertys .... without success. may you can give me some common recommendations how to light and shade such a scene propperly here is a pic and the hipfile... thx a lot Hey, I don't see a white soft box in yur scene. Just to make things clear, is this box a geometry object or an area light? Regarding HDR images in your reflections only; you can do that without your HDR light. If you specify the HDR image as an environment map in your material it will appear in the reflections only. I noticed that you have only the light name HDRI in your light mask field of your object. This means that this object will only be illuminated by this light. so the other lights will be neglected in this case. Hope this helps Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 hey man thx a lot! sry i ve erased the box.... it was a normal polybox with a white standard material ... may you can help me a little further and give me a veryvery rough setup greets Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 so ... the goal isn`t a physical correct rendering.... the bacground should me minimal and light but the reflective materials should look diffuse. a nice glossy look Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 a third sorry .... how i can adjust the lightlinker two stop my map reflection in the bulb? the helpfile sounds logic but somhow...? and may a little hint about gls and " index of refraction " i ve found something on the web what talks about 1,448 as an index someone in this forum told me something about 1/1.55. thx a lot Quote Link to comment Share on other sites More sharing options...
Jason Posted March 18, 2009 Share Posted March 18, 2009 So: *) your gold shader has a lambert of 0.2 - which is quite diffuse-ey. put this at 0.05. (The shader has a bad default, IMHO) *) your metal shaders have "Use Index Of Refraction" checked. this makes your surface have a fresnel falloff on your reflections - which is incorrect for metals. metals reflect evenly at all angles of incident light. (This is also a bad default in Houdini) *) your pocal object has a lightmask of HDR, make it * *) your pocal object has a reflection mask of nothing. make it * (why?) *) your pocal object has shading qualities of 10 - make it 1. (10 is hugely oversampled- 5-10x what you need, usually) *) you have a subdivide SOP, _and_ "Render as Subdivisions" set. Use only 1 of these - preferably the "Render As Subdivision". *) use a full environment HDR if you want metallic reflections all over your object. just a square arealight and a couple of pointlights are never going to give enough detail to reflect in your object. *) you had negative specular values on your aluminium shader- why? (your spiral ramp thing) Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 wow.! manymany thx .... you ve really helped me further... nice to learn in here Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 questions over questions.... i ve posted something already... how can i get a glow like effekt with pbr.... for example for the wire in the bulb... only comp? the glow material does not work with PBR ... at least with my settings... Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 ok something bout the light linker ore the maskfields if i type the name of a light in the lightmask field i only use that light for illumination that object wright ? and how to exclude somthing... for example for reflaction. let`s say i don not wanna have reflections of m HDR in my bulb ... Quote Link to comment Share on other sites More sharing options...
Jason Posted March 18, 2009 Share Posted March 18, 2009 questions over questions.... i ve posted something already... how can i get a glow like effekt with pbr.... for example for the wire in the bulb... only comp? the glow material does not work with PBR ... at least with my settings... Correct - you must use comp. The "right way" is to make the surface of the material have really bright values - like 1.0 and higher, and then only glow the very bright values in comp (ie, using the threshold). You can get a dreamy look if you glow values over, say, 0.5 - but it has a more realistic feel if only very bright values get glowed. Note that in order to preserve very bright values, you must save the render to a file format like .picnc (for Apprentice) or .exr (for commercial versions). Also, note that there are really two types of "glow" - the type that happens in the eye or camera due to imperfections in the lens ("bloom") and the type that is atmosphere being illuminated by nearby light sources (atmospheric optics). I think you're looking for the former type, although with PBR in it's current state it is wise to produce the atmospheric glow in a separate pass right now (its just too slow to be practical) and then comp it too. Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 at the moment people like you are the only chance i see geting a little deeper into rendering in houdini.. it s so hard finding recources for mantra, digital tutors a.s.o. quality but very basic... hopefully that will turn better in the future... many thx again Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 the thing with the exclusion of objects or hdr maps from reflection for specific object keeps me thinking... i can not find a field for reflectionmask in the glass properties... how to add it with VOB`s ... would that be the right way... thx Quote Link to comment Share on other sites More sharing options...
Jason Posted March 18, 2009 Share Posted March 18, 2009 the thing with the exclusion of objects or hdr maps from reflection for specific object keeps me thinking...i can not find a field for reflectionmask in the glass properties... how to add it with VOB`s ... would that be the right way... thx I'm not sure what a VOB is, so let me at least answer your other question: use a ^ symbol to exclude things. This is a standard pattern-matching operator in Houdini. * - wildcard ^ - exclusion So: "* light2" will use all lights except light2. Good luck, Jason Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 vop:) Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 my questions was about how to extend the glass shader a little .... i though with VEX ... VOP's that i can enter a reflectionmask... would that be the right way o exlude some objects in my case the HDR light from reflection thx Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 another thing is about GI, i ome from cinema 4d and there you can set the GI intensity for an object ore material. means you can affect only the raybounce intensity from an single object ore material. you can set it to 0 to exclude it from operation so that no rays are bouced to other objects. So with PBR and mantra : Do i have real raybounces if i extend the diffuse limit in PBR settings? and is it possible to exlude materials ore objects without rendering multible passes.... thx Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 somehow i can not type a "^" ......all fields in properties turn red while clicking and nothing is entered ,,, i tried to paste from the specil character list without succsess so back to the GI the lightning for the bright picture is exactly the same as for the contrasty one... i triede to exclude the reflections of the white box from the pokal object.. the goal is a contrasty glossy pokal over a bright background... i know physically not correct but... and the last issue for now is the shadow occlusion... how can i control ambient occlusion with PBR thank you impala_pokal_v3.hipnc Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 that include and exlude thing just does not work could that be a problem with the sop hirarchy ? are the maskfields in my geo container only affecting a material asigned directly to the geo sop? in my scene i ve assigned different materials to diffrent objects inside one geo node ... with a material node? i have still the problem that i can`t exlude the reflection ore specular of my HDR map (assigned to an environment light) from my glasshader ore the bulb only Quote Link to comment Share on other sites More sharing options...
hatrick Posted March 18, 2009 Author Share Posted March 18, 2009 jason:) are you there Quote Link to comment Share on other sites More sharing options...
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