roof edge surface not healing with wall surface

[Dave Brach]

I was wondering why my roof edge is not healing with my wall when they are the same surface.  I'd like those lines to go away.   Also please remind me how to align the surface on the end edge of the roof to be vertical?

 

[Laszlo Nagy]

I would zoom in very close and double-check to make sure the Roof's vertical eaves surface and the Wall exterior surface are in the same vertical plane. I would also check that the Roof eaves are set to vertical, just to make sure.

From your image, I can see that the Walls are probably Trimmed to the Roof so that is OK.

 

By the way, congratulations, you are the first user to post a question in the brand new Graphisoft Community Forum!!! You should get a "Fastest to Act" badge. 🙂 🙂

[thesleepofreason · Accepted solution]

Element intersection is based on building material and not surface so you have to make sure that part of the element that you want to intersect are of the same building material.

Of course dependent on the level of detail you model in and the construction of the roof (I assume you want a roof thickness) but to easily achieve what you seem to want regarding the exterior I would:

• make a composite for the roof with a thin top skin that is the roofing and a thicker bottom skin that is the structure
• set the structure material of the roof to the same that is used in the wall
• trim walls to roof
• override the outside surface of the wall to the surface you want.

This will give a result where the outside of the walls are nicely trimmed to a thin roofing.

[thesleepofreason]

Regarding the orientation of the gable edge surface texture. I think that the only way to change that is by making a new surface with a texture rotated to offset the roof pitch and then apply it to the gable edge through custom edge setting. So it wont be dynamic in regards to pitch changes.

[Laszlo Nagy]

The original question is not about the intersection of the 3D geometries of the Wall and the Roof.

It is about the line elimination on adjoining surfaces using the same Surface attribute.

Here is some additional explanation on the below image:

 

[Dave Brach]

Actually, thesleepofreason is correct, when I use the same building material for the structure of the roof and the wall, and override the outside surfaces, the line between the 2 goes away.  Adding a  thinner composite skin on top of the roof does create a nice way to have a thin edge surface on the side of the roof.  I don't completely understand how intersection priority plays into all this, but it looks good for now.

 

[thesleepofreason]

I would not say that its really clear exactly what the question is about. My interpretation was that is is about the exterior appearance of a model with rather low level of detail but high enough to use surface textures.

Yes, the line displaying is an issue. And yes, perhaps it is due to the edge surface and the wall surface being on different planes. Or perhaps it is due to it being different surface attributes. Your reply might solve this.

But there is something more to the question which is that the OP wants the surfaces to "heal" and that the OP wants the roof gable edge and the gable wall to look the same. Your reply does not solve this.

Even though the line is eliminated the texture of the straight roof edge will have a different origin which means that there will be a "seam" between the wall and the roof edge. It might not be so noticeable with the texture used in OPs model and your example but as soon as you use another type or more detailed texture (such as bricks) it will show. 

And for the roof gable edge your reply means a trade off between the line and the orientation of the texture.

I therefore replied with a method that under the assumed level of detail quickly solves all the issues mentioned by the OP regardless of the texture used.

[Laszlo Nagy]

Yes, you are right, I was thinking about only the first part of the two-part question. Your solution answers both.

[Laszlo Nagy]

What if you make the Intersection Priority of the Wall's exterior Skin stronger than that of the Roof Structure's Building Material? Then the Wall on the exterior side will reach up to the bottom of the Roof's top thin skin and the Texture issue is solved because we do not see the edge of the Roof Structure above the Wall on the Gable segment of the Roof, and no Surface texture misalignment presents itself.

[thesleepofreason]

I was a bit unclear; the reply regarding the orientation of the roof gable edge surface is to be read on its own - the method in my first reply solves the issue, and perhaps your suggestion about a composite wall with different intersection priorities will do it as well.

What I meant to say was that I don't know any way to control the origin/rotation of a roof edge surface texture apart from using the surface setting dialog which means that you need separate surface attributes for different origins/rotation. This is different from fills where you can control this, and scaling, using the construction method.