snapping point to a Null

[mirHadi]

hello

 

I'm stuck in a very strange situation where I can't not snap a single point of a grid to a the red null ( or blue one, doesn't matter).

snapping to points doesn't work for me... and I'm definitely doing something wrong.

 

 because I want to model a ground using tracking points, copy and pasting the translating values from each null objects is not rational!.

 

might you please help me?

 

thank you in advance

 

[Maurits]

You could use a attribute wrangle to get the position of the target null node and transfer it to the desired point groups.

This does requires you to group the points you want to snap to a null node, and to keep it simple a separate wrangle for each null node you want to use.
Al tough i don't think this is what you're looking for.

[mirHadi]

thank you Maurits!

 

It is always good to think in Houdini in groups, vectors, wrangles..    I like that!

in the modeling I like a little bit classic approach

[Werner]

I submitted this RFE 111days ago.

ID: 71848

[6ril]

On 08/02/2016 at 2:33 PM, Werner said:

I submitted this RFE 111days ago.

ID: 71848

!!! that's such an important feature ! I'm amazed that this feature isn't fixed, or rather repaired, since I've seen old tutorial where this was possible.

I'm wasting time trying to find a work around, I need to snap on nulls to create bones in the right place...

So far I've noticed that if you dive in the null node, there's 2 nodes: control and point. If you set the template flag on the point node, and with some luck (how weird) you might be able to snap to the null points.

 

 

[Ramteen]

Try using primitive spheres instead of null, works well.

[Kardonn]

On 6/22/2016 at 3:45 AM, 6ril said:

!!! that's such an important feature ! I'm amazed that this feature isn't fixed, or rather repaired, since I've seen old tutorial where this was possible.

I'm wasting time trying to find a work around, I need to snap on nulls to create bones in the right place...

So far I've noticed that if you dive in the null node, there's 2 nodes: control and point. If you set the template flag on the point node, and with some luck (how weird) you might be able to snap to the null points.

 

 

You may also be able to drop a Pack SOP down at the end of the chain and snap to that.

That's my little workaround for using Houdini's Nulls to place instance objects...there's no center point or xform data to grab, so you simple pack the stupid null and use its primintrinsics to derive the data.

 

Edit to add some Wrangle code for extracting instance attributes from those packed null objects. v@P of course is already your position data, this gives you the orient and scale.

matrix3 M = primintrinsic(0, "transform", @primnum);

vector scale = cracktransform(0, 0, 2, {0, 0, 0}, M);
vector rot = radians(cracktransform(0, 0, 1, {0, 0, 0}, M));

v@scale = scale;
p@orient = eulertoquaternion(rot, 0);

 

Edited July 26, 2016 by Kardonn

[toddfree]

So. I had the same issue. I wanted to be able to use the Nulls' position data, apply it to the points so that I could create a reference topology to model on, to ensure my model doesn't float around my background plate. I tried to figure it out with VEX but failed. So I used the old Point SOP. My Nulls are named "Tracker1, Tracker2, Tracker3,..." and so on. I created a grid, scattered 128 points on it (I have 128 trackers) and for the position parameter, I deleted the channel, and pasted the relative reference to one of the nulls. Then I substituted the number with `$PT+1` (so instead of Tracker1, I had Tracker`$PT+1`) . The "+1" is to account for the initial ptnum which is 0 (but that doesn't really matter). If you add the +1 make sure to use backticks. The expression looks like this —  ch("../../Tracker`$PT+1`/tx"). then duplicate it and change tx to ty or tz where necessary. Then, when you use Connect Adjacent Pieces SOP you will get something like the picture attached.

 

[davpe]

in 17.5 snapping to null works perfectly good for me