topic Re: Texture problem on steep sloped mesh in Modeling

Texture problem on steep sloped mesh

Anonymous — Thu, 25 May 2023 15:08:47 GMT

Hi.

I hope some of you out there can help me. I'm trying to project a texture onto a terrain in AC12, but somehow the texture shows up wrong on the steepest parts of the mesh. Is there a way to correct this? Is seems like the texture on these steep parts are projected vertically onto the terrain instead of planar like I want it to.

Thanks for any help

Re: Texture problem on steep sloped mesh

Anonymous — Fri, 28 Aug 2009 07:22:30 GMT

That is a normal behavior from a 3d software where you have a planar map on a mesh that slope much. One way to go is to place roofs on the most bad places and apply a terraintexture on that roof. But it can be hard to get a smooth edge between the mesh and roof.

christr wrote:
Hi.

I hope some of you out there can help me. I'm trying to project a texture onto a terrain in AC12, but somehow the texture shows up wrong on the steepest parts of the mesh. Is there a way to correct this? Is seems like the texture on these steep parts are projected vertically onto the terrain instead of planar like I want it to.

Thanks for any help

Re: Texture problem on steep sloped mesh

Anonymous — Fri, 28 Aug 2009 07:53:51 GMT

I could probably do that, but since the problem is pretty much all over, this would take days, and would still not look 100%. There must be a way to control this?

Re: Texture problem on steep sloped mesh

Anonymous — Fri, 28 Aug 2009 09:18:49 GMT

Do you have a free form 3d software like 3d studio or Cinema4d? You could control it there. But not here in ArchiCad.

Re: Texture problem on steep sloped mesh

Anonymous — Fri, 28 Aug 2009 10:13:44 GMT

Hi christr,

Maybe it can be fixed by GDL...

You would need to save the mesh as an object and edit the 3d script...

Long shot... but it worth try...

If you post a pla file of your mesh here I'll take a look.

Ah! And don't forget to create a signature in your profile with your AC version and OS and HW specs here on the forum... It will help us help you.

Re: Texture problem on steep sloped mesh

Anonymous — Fri, 28 Aug 2009 10:51:43 GMT

Hi.

I'm onto thin ice here with gdl objects, but you may very well take a look. Would be fantastic if it works!

I could of course take the model into 3DS Max or similar, but the project is just starting, so it would be amazing if I could work on the entire project in AC.

How do I upload a large file?

Re: Texture problem on steep sloped mesh

Anonymous — Fri, 28 Aug 2009 11:05:10 GMT

christr wrote:
How do I upload a large file?

No need to upload the whole project...

1. Backup your work...

2. Save your project with the "pla" extension (drop down in the save options) and delete everything except the mesh... (The pla file will put all the textures in a single package)

3. Zip it and upload the zip file here in the "Add an Attachment" Section of your post.

Re: Texture problem on steep sloped mesh

Karl Ottenstein — Fri, 28 Aug 2009 18:52:31 GMT

I have always had this problem with steep terrain meshes in ArchiCAD and have reported it as a bug.

I disagree that this is 'normal' in 3D software. The ArchiCAD texture mapping defects are worse than those illustrated, sometimes giving bizarre spirals of distortion. See this discussion:
http://archicad-talk.graphisoft.com/viewtopic.php?p=144913

For the same mesh that gives me problems in ArchiCAD, when I apply the same texture in Artlantis, everything is fine.

Cheers,
Karl

Re: Texture problem on steep sloped mesh

David Collins — Sat, 29 Aug 2009 06:40:51 GMT

Texture mapping in ArchiCAD has always had these issues, particularly for meshes (MASS) and TUBES.
Not much hope for a solution in GDL: to achieve full control you'd have to recreate the terrain using single primitive planes and then map each one using TEVE commands. Ouch!

See:

http://archicad-talk.graphisoft.com/viewtopic.php?p=127264&highlight=#127264

for problems getting a flag image to map properly on an animated flag object.

As Karl says, Artlantis can often do a better job of this than ArchCAD, but not always.
Another thing to try, at least in OpenGL: turn off smoothing.

Re: Texture problem on steep sloped mesh

Anonymous — Mon, 31 Aug 2009 06:07:43 GMT

Thanks for the replies.

I understand that this is a known problem, so I won't try too hard in AC. I will however try it in either Artlantis or 3DS Max. At least I know how to get it to work in 3DS Max.

Braza: Thanks for the help. I will see how it turns out in the other programs, and I will get back to you if I'm in need of your help.

Re: Texture problem on steep sloped mesh

Anonymous — Tue, 01 Sep 2009 20:39:32 GMT

just my two cents worth here >

if the jpg offered is the image that has problems > my opinion is that it looks very realistic vs. having the steep slopes with a green texture on them. a very steep slope in the natural environment would not have much if any vegetation on it.

to me it looks very good - realistic.

Re: Texture problem on steep sloped mesh

Anonymous — Wed, 02 Sep 2009 03:27:11 GMT

I've also had this mesh problem for sometime now. In my experience it only occurs on sections of mesh where the faces are steeper than 45 degrees. When modelling building sites this rarely poses a problem since they tend to be semi-flat. Make sure that if the contours are at 1m intervals that they are spaced a minimum of 1m apart in plan. Obviously where you have steep cliffs like in your example this may not be possible.

If you want to keep the contours accurate then there is no way around it I'm afraid but if you are willing to sacrifice accuracy for correct texture mapping I'd go around and spread out the contours where the texture ripping is occuring to make the terrain flatter.

Re: Texture problem on steep sloped mesh

vfrontiers — Thu, 16 Sep 2021 17:34:00 GMT

Just wanted to voice that this is still an issue in AC25!

If any solution has been found, please let me know!

Re: Texture problem on steep sloped mesh

Minh Nguyen — Tue, 21 Sep 2021 14:17:39 GMT

Hi Duane,

Thank you very much for the report and I am very sorry about the experience!

After some reseach, I found that the Mesh, as most 3D things in AC, has box-type Texture projection. This means there is an imaginary box around the mesh, the texture painted on its six sides, and texture on each mesh-triangle is projected from one of the six sides. The chosen side is the one with the closest direction to the plane of the triangle. So the steep triangles receive their Texture from the vertical sides, and probably from a completely different section of the Texture image than the neighboring non-steep triangles, which cause discontinuity.

What we would need is a Planar projection on the Mesh - all Mesh faces receive texture from one (horizontal) plane. Unfortunately, this cannot be set on Meshes. But, if you convert the Mesh to Morph and Select only the upper surface (Ctrl-Shift subelement selection) Planar texture projection may be set in the settings dialog.

This way the Texture fits the Morph, but the projection origin and direction will be modified. We can create a new Surface for the Morph and rotating the Surface Image with the desired angle. Then select the upper Surface and Align the 3D Texture with Set Origin.

I hope it gives a proper workaround in this case. Please let me know if you have any further questions!

Best regards,

Minh

Re: Texture problem on steep sloped mesh

vfrontiers — Wed, 12 Jan 2022 17:46:27 GMT

Minh,

Thank you for the perfect explanation...

As much as I love Archicad (and that's a lot)... there are always these 1% issues that frustrate me.

I cannot give up MESH for site contours... Just not WORKABLE for the many edits it will receive over the life of the project.

But I will consider the MORPHING idea and see if it's workable.

(BTW... I'm just now reading this from your sept. post!)

Re: Texture problem on steep sloped mesh

Luis M Dias — Thu, 28 Jul 2022 15:09:05 GMT

I've had the exact same issue and came here to find if I there was a real solution instead of silly workarounds like the ones being offered here.

I have to ask, is it really that incredibly difficult to have this option? More and more, we as architects rely on ortofotomaps to create a 3d context for our terrains, and meshes are the logical solution for this.