aelstein Posted April 11, 2008 Share Posted April 11, 2008 Hi-- This is my first post on od[force] but I have been lurking around for a while. I have learned a lot from all the forum contributors, so...thank you. I have the following question: Does anyone know if a physical sun position calculator exists within or has been created for houdini? What I would like to do is have a system where I could input a real world latitude, longitude, and time and have the system correctly position a "sun" in the "sky". This is a standard feature in many CAD programs (rhino, for example) but I have not been able to find it in Houdini. Maybe I am not looking in the right place though. I am an architect and have been exploring uses for Houdini in the context of generative design. The sun system would be used to drive a locator, which would in turn drive behaviour of an adapative facade system thks! adam Quote Link to comment Share on other sites More sharing options...
michael Posted April 11, 2008 Share Posted April 11, 2008 you should be able to finds the components of this with google... there isn't any such thing for Houdini as far as I know... but building it is trivial... give it a go and let us know how it goes and if you have any questions... Quote Link to comment Share on other sites More sharing options...
Wolfwood Posted April 11, 2008 Share Posted April 11, 2008 Oddly enough I just started working on this in my spare time. Sky colors are done (ignoring various division by zero bugs) and now I just need to do the sun (direct illumination). http://www.shadeops.com/skycolor/ Quote Link to comment Share on other sites More sharing options...
symek Posted April 12, 2008 Share Posted April 12, 2008 (edited) Oddly enough I just started working on this in my spare time.Sky colors are done (ignoring various division by zero bugs) and now I just need to do the sun (direct illumination). http://www.shadeops.com/skycolor/ How nice Wolfwood! Thanks! Atmosphere shader should work also with that code right? Edited April 12, 2008 by SYmek Quote Link to comment Share on other sites More sharing options...
Wolfwood Posted April 12, 2008 Share Posted April 12, 2008 How nice Wolfwoold! Thanks! Atmosphere shader should work also with that code right? I don't see why not. I use that code to generate lat-long environment maps, and then use those environments maps as a hemisphere area light. (Light Dome). Quote Link to comment Share on other sites More sharing options...
graham Posted April 12, 2008 Share Posted April 12, 2008 I actually started working on one a few months ago. Never got around to finishing it though. Might try and get around to finishing it sooner or later I suppose. Quote Link to comment Share on other sites More sharing options...
Jason Posted April 12, 2008 Share Posted April 12, 2008 Oddly enough I just started working on this in my spare time.Sky colors are done (ignoring various division by zero bugs) and now I just need to do the sun (direct illumination). http://www.shadeops.com/skycolor/ Nice work, Jim:) PBR needs a good one of these for a daylight illumination model; it really helps you get pretty pictures quite quickly. Quote Link to comment Share on other sites More sharing options...
stevenong Posted April 12, 2008 Share Posted April 12, 2008 Good stuff! Nice tip about using the code to generate environment maps too. Cheers! steven Quote Link to comment Share on other sites More sharing options...
Wolfwood Posted April 12, 2008 Share Posted April 12, 2008 Good stuff! Nice tip about using the code to generate environment maps too. The code posted can easily be converted to make lat-long maps in COPs. For the movie thing I made a sphere, attached the Cd point attributes, slapped on a constant shader, then rendered the sphere with my EnvBox thingy. (Makes reflection maps like the auto-gen...but I'm in control!!) EnvBox.otl sample.hip Quote Link to comment Share on other sites More sharing options...
flyingc Posted December 26, 2008 Share Posted December 26, 2008 Oddly enough I just started working on this in my spare time.Sky colors are done (ignoring various division by zero bugs) and now I just need to do the sun (direct illumination). http://www.shadeops.com/skycolor/ really a good thing, but i don't know how to use it..i build an otl with the code and apply it to a geometry sphere ,but it doesn't work. one more thing..i can't understand the theory about Chromaticity,can u recommend a place where i can't find some basic knowledge about Chromaticity? Quote Link to comment Share on other sites More sharing options...
atap3d Posted April 14, 2009 Share Posted April 14, 2009 http://www.shadeops.com/skycolor/ : Not FoundThe requested URL /skycolor/ was not found on this server. Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request. Apache/1.3.41 Server at www.shadeops.com Port 80 http://www.shadeops.com/ : Blogs can suck it.created with vim Quote Link to comment Share on other sites More sharing options...
kubabuk Posted April 16, 2009 Share Posted April 16, 2009 (edited) Hi, First of all many thanks for sharing, I'm still trying to get my head around it. Meanwhile testing I run across some questions and problems though. First of all, I'm getting strange artifacts around the horizon area (image1). Not sure but could it have something in common with too little zenith angle? The second issue is the brightness. Looks like the lower turbidity sky (around 1 value) gives black renders no matter how hi you increase bigness. Thanks for any help, really appreciate it. kuba PS. Quick update, looks like normalizing colour fixes some brightness quirks (some values were negative) Edited April 16, 2009 by kubabuk Quote Link to comment Share on other sites More sharing options...
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