itriix Posted August 3, 2009 Share Posted August 3, 2009 Well hello everyone, i have a question. to begin, i had a scene given to me, at some given size, which was WAY LARGE, for having to type in particle force values, and so it's simple practice to just do a transform, on the geo, and then do whatever particle sim i need to do at a reasonable scale, and then transform that back up by the inverse transform. and there is the thing, it all worked fine, but i did my shading at the small scale, and was testing the renders out, but then when i scaled it up, it looked super bad. and then i tried to tweak the shader in order to make up for whatever i thought the problem to be, and nothing. it still looked super bad! well that led me to thinking if there was some way for me to trick the camera into thinking the small scale geo is the size of the large scale geo. "the problem is, i have a matchmoved camera"... the thing is, if i just create a RANDOM default camera, and look through it, and then render, it looks FINE! it's only when i'm looking through my MM camera it looks terrible. well if someone has a suggestion please let me know. things i've tried to do, play with focal length and aperature to essentially tweak the camera to where it was supposed to be. this didn't work. gave me the same results as transforming the geo back. and i tried "scaling" the camera... this also had the same bad result. i feel like i need to somehow just use a default camera and apply the mm data to it... hmmm i'm stumped. any ideas? seriously appreciate the time Jonathan Quote Link to comment Share on other sites More sharing options...
itriix Posted August 3, 2009 Author Share Posted August 3, 2009 (edited) hmmmmm the more i play with this, i feel that it's gotta be something to do with the "pscale", "velocity numbers", "vex glass" shader, and the camera differences. *matchmoved cameras settings vs a default cam*... plus motion blurring. gonna have to just keep tweaking values. it's gotta be able to get back to the look of the "original" small scale look, imho... if that info helps anyone locate maybe "what in the vex glass" shader, or settings i need to adjust, i'd be glad to hear that and here are a couple images to see the crappy, scaled version look, and the small version Edited August 3, 2009 by itriix Quote Link to comment Share on other sites More sharing options...
itriix Posted August 3, 2009 Author Share Posted August 3, 2009 hmmmmm so after quite a bit of trying millions of things, it ended up being "kind of fixed" by: "reverse scaling" velocity and pscale... deleting the shaders, and recreating them AFTER the "inverse" scale of the geometry. lastly, seems that the only way i could get it "SOMEWHAT" back to how i had it was by lowering the shutter time... by eyeballing the values. all in all, it's back to ABOUT what it looked like, but not exactly there. it's missing a bit of motion blur "close" to camera. that's a bit sad but oh well, i've gotten it most of the way back now. Like I said, the main part that fixed it was recreating the shaders AFTER the xform... so i'm curious, either i was cracked out, or somewhere in houdini, is it keeping track of what values had originally been plugged into the "vex glass"? Cheers Quote Link to comment Share on other sites More sharing options...
Guest Swann Posted August 3, 2009 Share Posted August 3, 2009 and here are a couple images to see the crappy, scaled version look, and the small version I really like first image. Quote Link to comment Share on other sites More sharing options...
sam.h Posted August 3, 2009 Share Posted August 3, 2009 so i'm curious, either i was cracked out, or somewhere in houdini, is it keeping track of what values had originally been plugged into the "vex glass"? It wouldn't have been getting the values that you had when you created the shader. It must have been that you needed to scale up the velocity, pscale and any other attributes as well. Also, displacement values and frequencies and such would need to be scaled too. I'm pretty sure that rendering through a camera that is scaled up/down will look different to a camera that is in the exact same position but not scaled. Why didn't you just render the scaled down version if it was working how you wanted? Unless you are passing geo or particle caches to another app then it shouldn't really matter. Quote Link to comment Share on other sites More sharing options...
dbukovec Posted August 3, 2009 Share Posted August 3, 2009 hi! I had problems with rendering shadows, they dissapeared, trough fbx imported camera, which was scaled up. The easiest way to use the Fetch object to get the camera position, then I was able to render the scene correctly. Quote Link to comment Share on other sites More sharing options...
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