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Is there a way to convert a obj into a Vectron
Posted: Thu May 15, 2025 3:10 pm
by spartan00j
Hi I'm looking for a way to use the Vectron features on a obj model? Or any other 3D model. Or even possibly an animated model that I brought into octane Standalone.
Thanks
Re: Is there a way to convert a obj into a Vectron
Posted: Fri Jun 13, 2025 6:45 pm
by jobigoud
You can use a "Mesh volume SDF" node to convert an OBJ to a signed distance field. Then you can combine this with vectron primitives or other SDF objects with the union/subtraction/ink, etc. operators.
Re: Is there a way to convert a obj into a Vectron
Posted: Fri Jun 13, 2025 7:05 pm
by spartan00j
jobigoud wrote: Fri Jun 13, 2025 6:45 pm
You can use a "Mesh volume SDF" node to convert an OBJ to a signed distance field. Then you can combine this with vectron primitives or other SDF objects with the union/subtraction/ink, etc. operators.
Hi I think I got it. It seems it might have been the original model I was trying to use.
Does this process requires the OBJ model to have certain qualifications. Does it need to be a watertight model?
Thanks
Re: Is there a way to convert a obj into a Vectron
Posted: Mon Jun 16, 2025 3:34 pm
by jobigoud
Yes the source OBJ makes a difference. Because it will try to figure out what is the interior vs exterior of the model. If it's not an enclosed shape it can break the ray marching. You might see massive see-through artifacts when looking at the surface. Normally when the ray marching goes slightly beyond the surface it should get a negative "distance" so it will converge back to find the surface, but if it's a positive distance on both sides of a razor thin surface it can't converge. If you convert a simple quad mesh for example there is no meaningful interior to it.
What you can do to prevent this is add an "Offset" or a "Vectron displacement" node right after the Mesh volume SDF. This will give a little bit of thickness to the reconstructed surface and should remove the artifacts.
Re: Is there a way to convert a obj into a Vectron
Posted: Tue Jun 17, 2025 2:23 am
by spartan00j
jobigoud wrote: Mon Jun 16, 2025 3:34 pm
Yes the source OBJ makes a difference. Because it will try to figure out what is the interior vs exterior of the model. If it's not an enclosed shape it can break the ray marching. You might see massive see-through artifacts when looking at the surface. Normally when the ray marching goes slightly beyond the surface it should get a negative "distance" so it will converge back to find the surface, but if it's a positive distance on both sides of a razor thin surface it can't converge. If you convert a simple quad mesh for example there is no meaningful interior to it.
What you can do to prevent this is add an "Offset" or a "Vectron displacement" node right after the Mesh volume SDF. This will give a little bit of thickness to the reconstructed surface and should remove the artifacts.
Okay thanks. One last question. Where do I apply the texture. I have a obj sequence. I'm trying to apply a brick texture with displacement. But it doesn't seem to be working.
All I see is one solid color. I tried to adjust the UV transform. But all I see is just once all it color. Thanks
Re: Is there a way to convert a obj into a Vectron
Posted: Tue Jun 17, 2025 1:11 pm
by jobigoud
I don't think that conversion retains the UVs at this point unfortunately.
Re: Is there a way to convert a obj into a Vectron
Posted: Tue Jun 17, 2025 1:16 pm
by spartan00j
jobigoud wrote: Tue Jun 17, 2025 1:11 pm
I don't think that conversion retains the UVs at this point unfortunately.
Okay, I understand. But I tried to apply noise to the model. For displacement. And it gives me nothing.
Re: Is there a way to convert a obj into a Vectron
Posted: Tue Jun 17, 2025 2:36 pm
by jobigoud
Yeah it works with the original mesh polygons, not the displaced ones. You might try to use a Vectron displacement and put a noise in its Texture field. It will use the linear projection (XYZ -> UVW) though, not the Mesh UVs.