Transferring vertex normals for better toon shading?

Sonofbelmont

Hi
I know the chances aren't overly high of something like this being possible in Carrara but I figure I may as well ask anyway.
In Maya there is an option called transfer attributes which can let you transfer the vertex normals from one object to another object, I was just wondering if it's possible to do something similar in Carrara?

The reason I ask is because apparently it's a technique that can be used to get better results from toon shaders and similar methods have been used in games like Guilty Gear XRD.

You create your main mesh as well as a second simpler mesh and then by transferring the vertex normals from the simpler mesh to the main mesh you can have a detailed silhouette with simpler and less lumpy shading or something along those lines. Another approach I've heard used involves referencing the normals from a duplicate of the main mesh that has had its shape altered to smooth out lumpy areas.

Any help is appreciated
Thanks

evilproducer

Carrara can create and use Normal maps. One of the reasons is to bake a normal map from a hi-res object and apply it to a low res version of the same object. It sounds a little similar to what you are describing. I personally don't have experience doing this, as I'm using Carrara 7.2 and the feature was introduced in Carrara 8. There may be tutorials out there that describe how to do it.

DesertDude

Son of Belmont said:

Hi
I know the chances aren't overly high of something like this being possible in Carrara but I figure I may as well ask anyway.
In Maya there is an option called transfer attributes which can let you transfer the vertex normals from one object to another object, I was just wondering if it's possible to do something similar in Carrara?

Interesting you ask, as I just stumbled upon this technique about a month ago. No Maya here, I was looking into low poly trees...

Anyway, as far as I know there are no tools in Carrara to edit vertex normals. A question that needs to be asked is, can Carrara even read edited vertex normals? Or are they recalculated upon import? I know for a fact you can edit vertex normals in Blender and export to LWO, and LightWave reads the edited normals. Importing the same LWO into Carrara - no dice. Other people have had mixed success exporting out of Blender to fbx and dae, but I couldn't get either of those to work in Carrara or LW (respect the edited normals, that is). I can go into greater detail if you're interested or point you in the right direction if you want to explore the Blender route.

DesertDude

evilproducer - here is a quick and dirty example of edited normals (I'm no expert here...).

I took the leaves from a tree, brought them into...another app, then used some add-ons to "transfer the normals". As you can see, it creates a different kind of lighting. It's subtle, and you can imagine how it could be quite stylized and lovely. In these examples, the polygon normals have been edited. You can also edit each individual vertex normal if you want, to say, change the shading on a flat plane, light at the top and darker at the bottom.

Sadly bringing these edited objects into Carrara, as you can see, does not respect the edited normals. I hope I'm wrong though, and there is a magic switch I am missing.

DesertDude

Sorry to ressurect this thread, but Carrara can read edited normals, but only from an imported OBJ file and only if you select 'Facet Meshes' when importing. I was fiddling with this again last night (...don't ask, lol) and got it to work. You have to step outside of Carrara for a few clicks in Blender, but you can get your object back in with edited normals intact.

If anyone is interested I can make a mini tutorial. Also don't want to violate any TOS if I have to mention a few steps in Blender...and I flubber around in Blender when there...

Here are few examples - it's not 'all that' - but at least it can be done if one wants, like the original OP asked.  

The first two pictures show the original Carrara tree, the middle tree used the Normal Edit Modifier, and the far left tree used the Data Transfer Modifier where I transfered the normals from a bell shaped object.

The third and fourth pictures use a very hastily thrown together low poly tree using flat planes with alpha mapped leaves. The tree on the right is the Carrara tree and the one on the left has had the Normal Edit Modifier applied, then brought back into Carrara.