im doing the candle tutorial, but i ran into some problem in the beginning
of part2. when i add a ADD sop and enter this expression
centroid(“../Top_curve”,D_X)
centroid(“../Top_curve”,D_Y)
centroid(“../Top_curve”,D_Z)

i get 0,0,0
i should get 0.0,847042.0
meaning that Y should be at hte top of the curve.

can anyone help me out

Sorry I haven't done this tutorial but try changing the expression to
centroid(“../Top_curve”,0)
centroid(“../Top_curve”,1)
centroid(“../Top_curve”,2)

Also, might be worth looking at the spreadsheet for the add sop, RMB menu, and just double check that the point isn't actually where you think it should be. Sometimes expressions show 0,0,0 but they have actually evaluated.

http://sidefx.vislab.usyd.edu.au/houdini_video/by_topic/general/index.html [sidefx.vislab.usyd.edu.au]
here is the link if u wanna try the tutorial, or u can just downlaod the first 2 video. so u can see what im talking about.




mvh den

It's case sensitive, you seem to have put Top_curve and not Top_Curve.
That's assuming your post is the same as your hip file.

no. didnt help. i have a feeling that it has something to do with the way the ADD SOP, is added.
the tutorial clearly says bring in a ADD sop, but do not wire it with the top_curve. so i use TAB to bring in the ADD sop.
but is their another way to do it.


im a newbie at houdini
and i need help from anybody who did this tutorial, and made it work.


mvh den

Hi den,

I think Simon is right. You probably did not type the expression correctly. Houdini is case sensitive so the “c” must also be uppercase.centroid(“../Top_Curve”,D_X)
centroid(“../Top_Curve”,D_Y)
centroid(“../Top_Curve”,D_Z)

If you did type the expressions correctly, the next thing to do is to check the values of the Top_Curve. MMB on the Top_Curve Carve SOP & see if the “Center:” values are what they are supposed to be. If the values in the pop-up info window do not match the tutorial, you probably did a step wrong.

Cheers!
steven

den myos,

Make sure that your Top_curve carve sop is setup correctly - only firstv should be enabled and it should be at 0. Extract should be enabled.

Similar to what has been previously been say - make sure that you have spelled top_curve correctly in the centroid formula - but most importantly make sure that it is spelled the way you named your carve sop. (If you didn't rename the carve it will still be carve1)

MUTTOAB

http://hjem.tele2adsl.dk/aggromax/ [hjem.tele2adsl.dk]

i have put up the candle file for download, so please “save target as”
and see what the heck i missing. ive check all the response but nothing help.


mvh den

It's again some typing error, your carve sop is named “top_curve” , and your original expression was centroid(“../Top_curve”,D_Y), with uppercase T. So if you change it to centroid(“../top_curve”,D_Y) you get the expected value.

you were absolutly right, u all were.
it was a type O. but when i change the expression X,Y turn out right, but Z
gave me the number -1.11759e-008. cant figure out what that is connect to, since i should be 0.

i really sorry but im a real newbie to houdini.
u can ask me anything about 3dsmax though.


mvh den

Hey den,

The number -1.11759e-008 is really really small, something like 0.0000000111759. Even though it's not exactly zero, it is close enough.

Please don't apologise. Everyone makes mistakes or typos. Have fun!

Cheers!
steven

ok thx, but why is the Z value not 0, since its not linked to anything.
i know its a very low number but it still seems weird.



mvh den

hi everybody,

is this candle tutorial still around somewhere?
all links are dead, so if someone still has a link for me i'd be grateful

regards,

Manuel