luoqiulin
sorry for my bad English, i don't know weather i understanded your question. in viewport you can select the prims you want to transform,add a “delete” node,change “delete” option to “Delete Non-selected” all primGroups you want transform is here, in textpot type:

echo `primgrouplist(“/obj/geo1/delete1”)`

that's the groups

Thanx for replying,

Nop, that's not what i want to do. Here's to simplify the case : you have 3 spheres, each of the sphere has its own group (group 1,group2,group3). Later you want to modify the position of sphere2 (group2). So you attach a transform node to do the job. In the transform node , select the group/sphere then do the transformation (important : when selecting obj try to pick up from viewport , NOT from the group list !!! ). Done and you're happy with it. Suddenly you realize that u need to update the obj on the top level, and the modification will change the number of point. If you do that, absolutely the transformation u did before will gone wild. You will break your object for sure. So updating the obj will be a very bad idea. Otherwise you have to repeat all the transform. To deal with this thing, do not select obj from viewport, but you have to pick up group name from the group list in the ‘transform’ parameter. With this method , no matter you change your object, the transform node is still working fine.

But the problem with this method is : let say you have hundreds pieces of object (like glass breaking) , where each of pieces has its own group. For sure i don't want to pick up manually selecting group from the list , scrolling down hundreds item, trying to pick up which one is the right pieces, there are gonna be something like : pieces101,pieces102….pieces340 etc to select from. In this case , it's absolutely clear that you'll love to pick up INTERACTIVELY from viewport.

thanx

mrCatfish
Oops,sorry just read your message more carefully, you were already doing that. Yeah, that's very annoying.

yep, i'll be happy if someone can hack it what i'm confused, it's been version 11 and i believe some people already request the feature … ??? am i wrong ??

cheers

Hi, i got a lot of pieces of breaking object and apply an foreach to spread them randomly, each of pieces has its own prim group. I want to edit some major pieces so i attach an ‘transform’ node (i want to do some custom position adjustment) . I apply ‘tranform for each of selected pieces i want to adjust. Probably end up with 20-30 ’transform' node to adjust some major pieces i want to control. I want to keep this ‘transform’ node ‘alive’ which means, if in case i need to go upstream and do a bit of modification where the number of point will be changed, then i don't want to redo all the edit/transform i've done.

Back to the problem, if i modified upstream and number of point is changed, all the ‘transform’ downstream will screwed up coz it's using pattern based selection. So to have this ‘transform’ keep tracking what it's been done, i need to input group name instead of range pattern. But to get the group name, i have to select from drop down list, which one is which? i have to inspect in the viewport to select the proper group.

My question is it possible to input group name without having to select from drop down list (there might be hundreds items) ? Really i mean, i want to select them interactively the group in the viewport, then get the group name displayed in the ‘group’ parameter of the ‘transform’ node. I switch selection mode to ‘primitive groups’ , it help me select group properly in the viewport, but in the ‘transform’ param , i still got range pattern.

Anyone has any good trick to solve this problem?

Thanx

Hi, i got a weird case…
i create an object, in obj level, i set rotation-> rx ry rz to 4 5 6 consecutively. This object is still (no animation). Then in CHOP, i grab that channel using ‘object’ node, set compute to ‘rotation’. Then i export to .chan file. When i open the chan file with text editor, at frame 1, all the value are correct ( 4 5 6 for rx ry rz), but at frame 2 through the end of the range, i got : 3.99999952316284 4.99999952316284 6.

so the ‘4’ got converted to 3.99999952316284 , the ‘5’ is converted to 4.99999952316284 and ‘6’ is stay as 6. Why do i got this fractional value ???

the object is static , no animation at all. Anyone can give me the good reason ?

thanx

brianBurke
here's a method of doing that using foreach and attributepromote

for each loops over all the different ‘objects’

attributepromote averages the color over the ‘object’

wow, that's a pretty cool trick….. just like what i'm looking for, Thanx a lot for sharing it.

also , in the ‘group geometry’ node - in the ‘bounding’ tab, how to set the center parameter to : input's centroid, why can't i use the local var $CEX there ? why is it not accessible ? what the solution if i want to use the input's centroid?

Hi, i just want to know , if i have a poly object. Then i want to group it based on the volume (bounding box). So i use a ‘group geometry’ node. if i set entitiy to : primitive , then switch tab to bounding. If i start to resize the bounding box, it starts picking up some poly which ‘inside’ the bounding box volume. But this is not what i'm looking for… i don't want to select partial object. What i want is : if the bounding box NOT big enough to cover the whole object, i want it to pick nothing, it will only pick the whole object if the bounding box is covering the whole obj. So i want to pick the whole object or nothing at all, not picking some poly which is part of the objct.

how to do this using group node?

thanx

Hi Brian, this is AWESOME. i didn't think it was so easy…. COOOL

thanx a lot.

No way out?? if there's no easy way to do that… means have to go to hard math ?

Hi, has anyone here ever do importing/exporting fbx from modo to houdini. I got problem where the cam is always wrong direction. I tried to modify transform order/axis order with no luck. Anyone has a solution ? Collada works better in modo-houdini crossing where i got perfect cam. Also is there any way i can bring the camera data like focal length/aperture/film back automatically ?

thanx

Hi, i'm trying to render out a normal map. The problem in Hou that the normal map is translated (rendered out) as relative vector to the active(render) camera. I need it to be in world absolute vector. How to do that?

thanx.

tamte
just plug your xform_ref node in the flow (between each1 and merge1)
it seems not to be updating pivot values just by referencing them so you need to help it a little bit by making merge1 directly dependent on that node

This is just perfect ! thanx for the nice tipz. It's a bit wierd have to do so, but anyway it solve my problem.

thanx

Soothsayer
I don't get an error and the result is as expected.

Sometimes foreach “forgets” or “doesn't update”. Try restarting and see if that helps.

ups that's so wierd, yep it suppose to give me the same result. And yes sometime it doesn't update , need to refresh it somehow … btw i'll recheck and come back later. Let see if something wrong with me or the app.

thanx

zarti
here it is ,

its parameters are over the ‘ DONE ’ null node .
those names aren't so clear , but play with the sliders to see what they do .



.cheers

Hi Zarti thanx a lot for sharing. i'll try and see if i hit a problem then i'll be back.

thanx

fsimerey
Another method with only 3 nodes much faster than with a FOREACH SOP.

1. FACET with ‘Unique Points’
2. PRIMITIVE with a ‘Scale’ of 0, 0, 0
3. FUSE with unchecked ‘Remove Degenerate’

I put a switch to test the 2 solutions.

Change the row/col of the grid and you can see, it is much faster with these 3 nodes.

Great! that's a good workflow. I tested it… it shows a quite big different in processing time. COOL.

zarti
hi ,

started as a curiosity to consume and just figured out how to build a spiderWeb DA . if not complete , there is the skeleton .

let me know if you need it .


love houdini
.cheers

Hi Zarti,
yes i like to try it if you don't mind, thanx for sharing anyway

Hi, i attach file where you can see that i managed to use foreach by using ‘each group’ mode. I found something wierd , as you can see i use 2 foreach, foreach 1 is correct one (left side). So using ‘centroid’ expression, i can put the group name at the top of the centroid of each group. But i tried another method in foreach2 , this time i use local var (group centroid : $GCX,$GCY,$GCZ) , but the result is not like i expected. The group name labels are overlapped each other. Is there anyone can help me out?? what 's the problem ? It should give me the same result as my first method.

thanx

jeff
One way is to move the Extrude down to the bottom of the chain. The Primitive SOP is doing what it is supposed to: work in individual primitives.
See the attached example file.

If you really need to move chunks of geometry, yes use the connectivity SOP and the Transform SOP in place of the Primitive SOP. You need to calculate the centroid of every chunk and then use that as the pivot point in the Transform SOP. You can do that in a number of ways: ForEach SOP on each chunk as early up as you can, Create a point per primitive and move that point to the centroid and then index in to the point position as it is carried along with the boxes.

Thanx Jeff, following your suggestion by using foreach, i've just managed to solve my problem. This foreach SOP , i've never touched it before, it's like a ‘black box’ to me. But as i learn to use it , it's really2 powerfull node…. i found this node really cool.

thanx

dinkleberry
I had to do something similar to #1 recently, and have attached a file with one way to do it. There might be a simpler way.

Can't help you much with #2 but I think the foreach SOP could be very helpful there too.

#3 - The hou.lvar(“…”) function gives you local variable values, e.g. lvar(“PT”) and lvar(“PR”). (You don't need the “hou.” prefix in parameter expressions

Hi Dinkleberry, thanx a lot for the sample file. That's exactly what i'm looking for. Great !

thanx

Hi, i attach a scene file, i want to move per box (each box is a collection of 6 prim or poly). The one in the left is translate only (i'm using primitive node to add translation using expression), so have no problem. The one in the right side, i add rotation based on connectivity class (i add expression in the primitive node), but the result is not like i want. it's more like a taper effect. I want each box to have its own rotation. It looks like each poly trying to rotate using its own center ?? any idea? how can i rotate each box as a group using the pivot or its centroid??

thanx.