Meshroom to Blender

Welcome to my journey with Meshroom for Blender. I am an amateur Blender and Meshroom user, so please stay with me while I try and figure out what is going on. If you have any answers, please drop 'em below.

So I was following this tutorial by CG Geek. When the tutorial came to where one should add the decimate modifier, I noticed my mesh has 2 023 221 faces before decimation, while CG Geek only has 446 243 faces. Cool, my object is a lot more detailed but alright, I’ll decimate by a factor of 0.15 to roughly get to CG Geek’s decimation number. All went well until I had to switch from the Blender renderer to the Cycles renderer and add the texture using nodes. The problem was that there are two textures instead of one as in the tutorial. What happened was this (all in textured mode):

I think you need to set to shade smooth… in 2.79 this is on the panel on the left of the 3D View (In object mode)… on 2.8 press F3 and type “shade smooth” in object mode.

I try the other texture and it comes out like this:

Great. That looks even worse. Maybe the textures are two parts of a half? Still doesn’t work:

I go back to the Blender renderer and now it looks like this.:

Ok, maybe the .obj shouldn’t be imported with Blender render, but rather into Cycles. This work’s perfect. Even with the Decimation modifier applied and the Smooth modifier activated. Only thing now is, there are still two materials (TextureAtlas_0 and _1), each with their own complicated set of node setups:

If I disconnect the Surface connection from the Material Out node half of the texture disappears, which would imply that each texture (TextureAtlas_0 and _1) makes up half of the entire texture.

Ok, Cool. I’ll try and add a PrincipledBSDF between the Shader Add Refl and Material Out. Maybe now I can follow along with the tutorial? Well, I could, but then I have to set up and change across two different materials. This is annoying to switch between two textures all the time:

Surely I did something wrong in Meshroom to get two materials instead of one. I do some digging online and find this post.

Back to Meshroom. I change the unwrap method from basic to LSCM. Hopefully, this works…

It did. I just took super long. I don’t know how to make this part of the process shorter, but it worked so I’m happy. Now I can finish the tutorial.

Thanks, @yogyog. It was set to smooth. The problem appeared to originate from how I generated the photogrammetry model in Meshroom.

When you import a OBJ into cycles you get a material that… well it works, but 90% of it is doing nothing. Keep the image texture and the output, and delete everything else… then add a principled going into surface with the image texture going into base colour.

As for some areas of the image showing up white (or black)… I’m not sure. did you say the mesh has two materials? Or that there are two objects each with their own material? It looks like meshroom is generating two maps to make up the scene. Do you get two objects, each with their own material when you import the obj?

Little tip - when posting a screenshot for help… show the whole screen. The outliner and settings may provide handy clues.

did you say the mesh has two materials?

Yes, the mesh had two materials applied to one object. Somehow that jumble of nodes you get when importing into cycles makes the two textures work together on the single object. There was no second object.

Thanks for the tip :+1:. I’m quite new to these forums. I’ll keep it in mind for next time.