It's been a while since my last post, sorry about that...
I was playing with Houdini for the last 1 year, did a couple of jobs with it. It saved my ass a couple of times and I can say that I completely felt in love with it, and I really felt sorry for the years I spent without Houdini. Anyway, after a while later I decided to try to complete the jobs more and more with Houdini and try to go away from Maya a little bit. I'm not going to enter the valley of the differences of the two programs and how awesome Houdini is etc. but I need to say that it feels awesome.
Yet, there is another job that I need to finish up (the deadline is tomorrow). The job is about a tire brand etc. Lets cut the chase, the object was not looking good just because they've sent us the production model that they are using to produce the product in the factory, and you now this kind of nurbs models are a little bit too perfect, has sharp edges and a lot of details. In Maya, to break this perfection, I generally use the round corner shader to smooth the sharp edges and it works perfectly. But in Houdini you don't have this kind of already built in shader but you have the powerful VEX.
I've first searched for it on the web, there was microBevel from Simon Barrick but it was not working with Houdini 11 (by the way I need to thank Simon, for his fast and friendly responses to my e-mails).
Then I tried to find a paper about how to smooth edges of geometries in render time. And I found a document about the round corner shader in mental ray from Hakan Andersson (the famous master zap). So it was pretty obvious actually...
Here are the results of my round corner OTL with different curving choices:
and here, the tire with and without round corner shader:
Edit:
I've removed the OTL links because they are not working with Houdini 13 anymore, but good news! I've created a simple shader that does the trick without needing any OTLs. You can download it here:
round_corners.hipnc
Also I've did it from scratch, it should be much cleaner, faster and easy to follow. Please let me know if you have any suggestions for the shader. Have fun!
I was playing with Houdini for the last 1 year, did a couple of jobs with it. It saved my ass a couple of times and I can say that I completely felt in love with it, and I really felt sorry for the years I spent without Houdini. Anyway, after a while later I decided to try to complete the jobs more and more with Houdini and try to go away from Maya a little bit. I'm not going to enter the valley of the differences of the two programs and how awesome Houdini is etc. but I need to say that it feels awesome.
Yet, there is another job that I need to finish up (the deadline is tomorrow). The job is about a tire brand etc. Lets cut the chase, the object was not looking good just because they've sent us the production model that they are using to produce the product in the factory, and you now this kind of nurbs models are a little bit too perfect, has sharp edges and a lot of details. In Maya, to break this perfection, I generally use the round corner shader to smooth the sharp edges and it works perfectly. But in Houdini you don't have this kind of already built in shader but you have the powerful VEX.
I've first searched for it on the web, there was microBevel from Simon Barrick but it was not working with Houdini 11 (by the way I need to thank Simon, for his fast and friendly responses to my e-mails).
Then I tried to find a paper about how to smooth edges of geometries in render time. And I found a document about the round corner shader in mental ray from Hakan Andersson (the famous master zap). So it was pretty obvious actually...
Here are the results of my round corner OTL with different curving choices:
and here, the tire with and without round corner shader:
Edit:
I've removed the OTL links because they are not working with Houdini 13 anymore, but good news! I've created a simple shader that does the trick without needing any OTLs. You can download it here:
round_corners.hipnc
Also I've did it from scratch, it should be much cleaner, faster and easy to follow. Please let me know if you have any suggestions for the shader. Have fun!
Comments
use the round corner in slots that accepts surface normals.
So with the new materials in houdini 11 create a round corner node and attach its result to the "surface normal" attribute of the "surface model" or just follow what is connected to it and try to replace any "global variables" nodes that has its "surface normal" slot connected to some other nodes with the "roundCorners node. Then increase the samples to 6 or more in roundCorners then promote the radius and bias parameters or just connect a constant to them, and set the bias to 0.001 to start and play with it incase you get artifacts, and then set your radius according to your objects scale... hope it is clear enough...
It was the BIAS - I never had it that low. It's always the same - I try every possible combination, but not the right one.
Thank you so much
Cheers
There should be a PDF version also...
Thanks!
(tested on v11 and works)
I've updated your otl to work with v12.5. I haven't put it through rigorous testing but if you'd like to post it and get some feedback, let me know. I'd also be interested to hear any suggestions to further speed up the calculations.
It would be great to have your version.
And regarding to the speed improvements, the shader is simply firing rays perpendicular to the normal at the rendered pixel and tries to find some other objects to blend the normal with. So the only speed gain can be obtained through limiting the search distance and limiting the amount of search directions (samples), and as I remember I was already doing it by using the user supplied radius and sample count.
Also I was both searching for concave and convex edges. So limiting the search for only one type of edge should double the speed.
Also Hakan Anderson's version (the mentalray version) were using only 6 rays but I was only be able to get good results with 12 rays.
tell me does this allow rounding between 2 seperate intersecting surfaces like the one in mental ray XSI ?
i see some people have modified and updated the script created here. where is a good place to get the latest best version ?
thanks
jono
is there any chance that you'll create a version for Houdini 13?
Sorry for the late response, I didn't notice your update.