Hehe, the never ending story…
I was there too - don’t give up!
Mike, I’m no expert on this but I think what baking means is to basically just transfer information from a high to a low poly model. This can be e.g. texture or also geometry as bump maps (which is depth info stored for each triangle).
This YouTube playlist has a series of short videos that explain the high poly to low poly workflow. It should give you a basic understanding of the concept in a short time. You can start with the second video, in the first video he shows how to sculpt the high poly model. RC makes the high poly mesh for you.
https://www.youtube.com/playlist?list=PLboXykqtm8dyMYptKj-tDeJSA2ljqG4_A
For RC you would export a mesh to be used as a reference (high poly mesh) in a modeling program. In the modeling program you would create a low poly version of the model with UV’s. Then you would import the low poly mesh into RC to texture it.
How basic can I get, but what’s UVs (like XYs (coordinates) but different?) and what would a modeling programme be - Pointfuse? MeshLab?
Yes, exactly. UV is the XY of an unwrap.
No idea about the software though…
Thanks kindly. Next silly question - what’s unwrap (I have vague idea but would like to hear it)
Unwrap faces of a 3D object onto a 2D space (texture map). There is a ton of free documentation/tutorials on the web from basic to super advanced 3D for all kind of software.
Ok, I’d better get looking. Obviously unwarpping millions of triangles of a mesh is a bigger challenge than a cube (not sure why you’d want to).
Aha - perhaps UV means the coordinates (before unwrapping) of ea vertex, which remain attached to ea vertex after unwrap. Or the opposite.
This image shows an RC mesh.
This image shows a low poly mesh (with UV’s) I made in Blender using the RC mesh as a reference.
This image shows the low poly mesh textured in RC.
This is an image of the texture showing the Blender UV layout.
Here’s a link to the low poly .obj file:
http://www.digital-mapping.net/forums/CapturingReality/2018/low-poly.zip
Nice work Bill!
Could you give us a rough idea of how much additional work it is from the RC model to your nice low-poly?
Do you really texture it in RC? How do you avoid the ivy ending up all over the place? Use only one image?
Glad you’re watching this Gotz, as someone whose output is technically accurate, reliably measurable model and/or orthophoto (am I right?) rather than beautiful seamless visual work-of-art.
Not having yet gone into ‘ton of free documentation/tutorials on the web’ as Valerio recommended, I don’t yet understand the workflow/images Bill helpfully offered. But I’d wonder whether such super-simplification (single flat image on single flat plane, no ins and outs) would be relevant for technically accurate output?
Hi Tom,
you’re right, that’s my main objective.
But I also see the advantages of having simplified models. Bills certainly is an extreme example.
It always depends on what kind of accuracy you are after - this is always an important question. I am sure Bills model is not far off, otherwise the texturing would not have worked well. It certainly helped that the structure is rather new (thereby straight) and the geometry is generally rather simple. It also depends on how you do it. If Bill really used only one image for texturing and took that from far away and dead centered, then there isn’t too much that can go wrong since there is not too much depth in the image.
Since Bill also deals with archaeological stuff, I am sure he knows very well what he’s doing. I think I remember somer really good stuff on his sketchfab protfolio. 3D for research, not just fancy looking playthings.
Yes, the model is very simple. It could be made more detailed by adding the white trim boards, etc. There are 10 cameras in the scene. They were all used to create the texture. I also tested texturing the model with Maximal textures count, one texture at 4096x4096 and it looked good.
Here is an image of the low poly model with the RC high poly reference mesh.
Götz, if you download the model and look at the texture of the second shorter board leaning against the shed you can see that the texture appears distorted since I didn’t create geometry for that board. Likewise the areas of ivy that are furthest from the low poly model look a little odd, but not bad.
These were photos I had taken to test a camera, but never processed in RC until I put together this example. The whole process of making the high poly in RC to making the low poly model in Blender, and texturing the model in RC was in the neighborhood of a couple of hours (with some fiddling).
Here’s a link to the RC project complete with photos, simplified mesh, and low poly textured mesh. File size around 150 MB.
http://www.digital-mapping.net/forums/CapturingReality/2018/RC_high-low_poly.zip
In the 3D view the low poly is best viewed as solid or sweet.
Hi Bill, Thanks for the replies.
Really nice work on the quality of the texture.
My problem is ensuring RC or whichever 3d tool I am using utilizes the UV and material textures. Here is an example of what RC exported and my confusion on how I optimize the UV map.
This is what RC created for UV maps and the white UV would be my low poly UV map I created in Modo. What I want to do is utilize 5 texture maps. RC created 4 as you can see on the right and 1 more for my new LowPoly UV.
Utilizing each 8k texture is key to ensure I am getting the best quality texture for my model and if I have 5 8k textures I want to use them all up. But why isnt RC exporting them properly? or creating them properly?
Also if I want to reimport new UV’s using Modo or any other tool how to I create a proper UV map using 5 UV sections to optimize 5 8k textures. (If that makes sense).
Thanks!
Hi Mike,
With the majority of my projects I use targets with Ground Control Points so that the model is in world dimensions. Since I know the actual dimensions of the object, I know about what dimension I want a pixel to be. Lets say my units are meters and I want a pixel dimension of about 1 millimeter. I will either use the Unwrap style Fixed texel size with the Texel size set to 0.001 and Unwrap, or I will use Unwrap style Maximal texture count and change the Maximal textures count and unwrap until the Texel size displayed in the Selected model(s) dialog is about 0.001. Often times the Optimal texel size will be a lot smaller than 1 millimeter and would be overkill.
The Unrwrap Style Maximal texture count is the one I use most often when exporting simplified meshes. Here’s an image showing the dialogs for Maximal texture count and the Selected model(s) for one of my projects. Hopefully it will make the previous discussion clearer.
When you export your model what Tile type are you using? I believe modo supports UDIM, you might want to try that if you haven’t already.
Another thing I do in my workflow is build the initial model in Normal Detail without a Reconstruction Region. I then use Set Reconstruction Region and use the Filtering Tool to remove the unwanted outlying area. This removes large polygons (and the closed box). I then use the Simplify and Unwrap tools on the resulting model.
Thanks Bill that was extremely helpful, I feel like im super close to getting this working but my current issue now is after I create a new UV and material. When I try to reimport I get the error “texture coordinate u or v is bigger than 1”
Is there something I need to identify before I reimport it back to RC?
Thank you so much!
Mike
Hi Mike,
I have modo version 9 and played around a bit with importing multiple textures from modo into RC. As far as I can tell the best way to do this is to use the 0 to 1 UV space. The way to have multiple textures utilize this space is to use multiple materials, each with a texture. I have attached a modified model of my shed front that I made six blank textures for in Photoshop. In modo I created six materials and assigned one of the textures to each of the materials. I then selected different elements of the shed and assigned different materials to them. When I imported the model into RC all six textures were there.
Here is an image showing the six textures I made in Photoshop.
Here is an image showing the six textures exported from RC after texturing.
.
This image indicates the Tile type that exports multiple textures that utilize the 0 to 1 UV space.
Here is a link to the .obj file I modified in modo along with the 6 textures. It also includes a folder named test that contains the model and textures exported from RC after it was textured. If you download the RC project from one of my previous post, you can import modo.obj and texture it to see how it works.
http://www.digital-mapping.net/forums/CapturingReality/2018/modo.zip
Here’s a link to the model on Sketchfab: https://skfb.ly/6wyxV
You can use the Model Inspector on Sketchfab to checkout the wireframe, textures, and UV’s.
Hi Mike,
I played around some more with using UDIM’s with RC and got it to work. I renamed my materials and textures to the UDIM naming convention.
Then I moved my 6 UV’s form 0 to 1 UV space to UDIM’s.
I imported it in to RC, textured, and exported the results. It worked as hoped.
I tried combining all the textures into one material and importing into RC, but got the message “A texture coordinate u or v is bigger than 1”, so it appears each UDIM has to have it’s own material in order to import into RC.
Here’s a link to the modo UDIM .obj:
http://www.digital-mapping.net/forums/CapturingReality/2018/modo_UDIM.zip
Hi Bill,
Appreciate all the help dealing with these pesky UV’s, I think I have the handle on assigning UV’s to a individual mesh.
Im only running into some minor issues now when I have a lowpoly mesh with UV’s and a highpoly mesh with UV’s. Selecting both layers and importing back into RC doesnt align properly and where I should have 6 UV’s it might create 12. I may have to merge both meshed first before I export back for RC.
I played around a lot this weekend exporting and importing different variations of UV’s and how I can import them back. The problem now is dealing with 2 different meshes on export but that should be a lot more straight forward now.
Thanks again for all your help trying to understand things better.
Hi Mike,
Merging them sounds like it might be a good idea. As long as they have separate materials it shouldn’t be an issue separating the meshes when you bring it back into modo after texturing in RC.
Thanks to your post it helped me to get a better handle on things.
Hi Bill,
Just wanted to thank you for the help, its really progressed my knowledge in this space on how to handle working in 3rd party modeling software.
Understanding UV’s and how to utilize them for low poly models has been extremely useful.
Right now I am focusing on remodeling every flat surface in my interior model and leaving the rounded contours to the RC high poly mesh. Its a slow process but the results are very satisfying.
I should note for anyone trying this, lining up your new low poly model with the construction from RC is very important in order to get clean textures. There probably will be a lot of playing around for the final model to get the best texture quality but now that I can create my own UV’s, I can really get out the detail.
Here is an example of the low poly walls and floors (In currently 1 8k texture), note the distortion was due to the missing high poly meshes of the furniture. The next plan is to blend the two models to really clean things up.
