procedural uv-ing

[Saya]

Hey Odforce,

I hope you can help me. I want to UV and Texture several different shaped objects. I have several box like shapes that will become buildings later. I have in this houdini file an attemps to solve this issue. I have trouble getting something like the result made in maya, like in the picture. I would like to have this result for all of my shapes so I can apply a repeatable texture. The buildings are everywhere in world space but I dont have the translations or rotations of the buildings. So for it to work, it should not matter where the building is. I tried to get the same result as in Maya, for the UV, when the building is on worlds orgin. I tried to get select a procedural seam and use UVpelt. but it gives me the rotated result. As shown in the second picture.

Can someone help me out?

 

Edited July 31, 2017 by Marcomeeuwse

[Saya]

here is the houdini file

 

UV issue.hipnc

Edited July 31, 2017 by Marcomeeuwse
updated file

[f1480187]

I would use UV Flatten node with Seam Group edge hard-coded if the seam edges are same across all generated meshes. UV Flatten will axis-align island. You may try to apply it before PolyBevel, since it properly handles UVs.

axis_aligned_uvs.hipnc

[Saya]

Thanks, didn't thought about using that poly bevel later. That saved most of it

That seam group gave a me an idea. It is not possible for the object to hard-code/select a primitive, edge or point, as they are not always on the same position for all the other objects. So the selection of the seam needs to be procedural. I selected the top points of the object and placed a long box on one of the points, which will be the selection for the group node by bounding box. I did the same for the edge selection of the bevel. Im not sure if it could done any better, but it works. And the UV Flatten node works like a charm that way. Thanks!

But i'm left with only one problem. Since Houdini 16, the group node is split up and the fuction @p.y==$YMAX does not work anymore, vex is now needed and i tired this: @P.y >= getbbox_max(0)[0];
That only works on the current position of the object, when I translate it on x y or z, the selection is changed. I think i don't fully understand the vex thingy. I only want to select the top points of the object

Cheers

axis_aligned_uvs-2.hipnc

[f1480187]

getbbox_max(0) returns a 3-float vector. You are accessing it's very first component, which is same as using $XMAX in the old Group node. You should use "getbbox_max(0).y" or "getbbox_max(0)[1]" (same thing).

[Saya]

Ah i see. Then that [0] makes sense, [0] is x, [1] is y, [2] is z. So if (0) stands for a 3-float vector, what are the other possibilities? is (1) a 3-integer vector?

[f1480187]

0 stands for the input number. It is common for functions used in VEXpressions.