Align normals of a primitive to a single point of another primitive

[Maxc]

Is there away to align the all the normals of one primitive to a single point of another primitive? I am trying to achieve a bulge type deformation with a point VOP using the normals as a vector.  Currently I can align the normals of the first primitive only if the second primitive has the same number of points. I only need one point for them to align to. Thanks.

046 displace_along_vector.hiplc

[rich_lord]

Heres a simple way.

Create a point with an add sop

Add a normal to that (I've used a point wrangle)

Use either VEX or VOPS to copy that normal onto all the points of you original geo.

In this file is both the VEX and the VOPS way.

copy_normal_from_point.hiplc

[Maxc]

Hi Rich,

Thanks, that's great  and gives me some new ideas but not quite what I mean in this case I don't want them all to have the same normal direction. I want  each point to have a normal  derived from it current position subtracted  from the single point.  In the same  way you can use a  wrangle  with @N = @P;  this makes the normals directed to the zero. I don't quite understand how this works admittedly, I just want to control where "zero" is and have all the normals point there.

I'm after a more efficient way of what my VOP is already doing.   My issue is that I have to have the same number of points in each. 

[rich_lord]

Ohhh, I see.

Ok, here is your answer. Its done with some vector math. If you subtract two position vectors from each other, you get a direction pointing from one to the other. Then you normalise that vector to get them all be of length 1.

Here it is done with VEX and VOPS.

normals_point_away_from_point.hiplc

[Maxc]

Hi Rich,

That's brilliant. I didn't realise you have to initialise the add point position and also in the VOP add a constant ptnum. Thank you for your help. I've still got away to go before I understand the vex wrangles, but this helps makes sense.

[ashkan rahimi]

 

 

 

 

 

 

 

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On 2/4/2017 at 6:46 PM, rich_lord said:

Ohhh, I see.

Ok, here is your answer. Its done with some vector math. If you subtract two position vectors from each other, you get a direction pointing from one to the other. Then you normalise that vector to get them all be of length 1.

Here it is done with VEX and VOPS.

normals_point_away_from_point.hiplc

hi guys. I had the same question and it's solved. thank you, Richard, I just don't understand what does that constant node (that you add to ptnum node) do. I appreciate if you would describe it. thanks a lot