Multi OBJ

[mirobimbo]

Marcus, I do not think it is problem with position multiple mesh in scene.
Position mesh objects in obj files is firmly given. When I save objects in rhino into obj, open it in blender, change anything, save and open again in rhino, it is at the same place.

[matej]

Yea, importing additional geometry for the same scene through a different .obj should give no problems, unless the export scaling factor has been changed.

[face]

I think Rhino isn´t an animation program, it saves the position of the mesh in the obj-file because there are absolut.
If you animate a mesh with an animation application, you only change the SRT.
The SRT (Scaling/Rotation/Translation) is a matrix. The original Mesh is multiplied with this matrix, so you get the new positions.
If you save the mesh, you save then not the multiplied positions, but the original (unanimated) positions.
I think that´s the background why you can, in the most packages, bake the animation to the timeline...

face

[maudeeb]

The workflow is meant to be like this: You set up the geometry, UVs and basic materials in your favourite 3D app and then export it as OBJ file. Then this OBJ is loaded into Octane, where you then tweak/finetune the materials and render the whole shebang.

The main problem with multiple mesh nodes is that you need place their meshes somewhere. Usually the position of the geometry in the OBJ file is not the position in the scene. And interactively placing meshes in your scene is currently not possible in Octane. We are working on these things, but they are not trivial.

And remember: Octane is not a modeling app but a renderer.

Cheers,
Marcus

Thanks Marcus ! I appreciate the explination. I realize we're not dealing with a modeling app, I just wanted a better understanding of why octane was designed the way it was. I also realize how complicated it can be to go back into source code written with one purpose in mind and try to change something as fundamental as this !

As far as object positioning - I go back and forth between apps like Maya, ZB, Magics, FreeForm Modeling System, ect. all day long. As long as I set everything is set up properly at the start, object positioning relative to the scene or worldspace is always consistent with separate object export and import. Same with scale. I always assumed position and scale were components of standard obj export and easily translated into the application importing the geometry. I also realize Octane may have an architecture that's radically different in how it works in 3D space and what looks simple in other apps isn't in this case. I've noticed the "voxel" message on object import and wondered if the geometry isn't being completely rebuilt as a voxel volume.

The two biggest headaches I have right now are finding the desired material node to tweak (if there’s a viewport/ scene based material selection method I missed it - user error !), and adjusting light emitting objects’ position in a scene. I probably need to test render the scene first in Mental Ray to get the lightcards positioned where I want them, but it would be great to be able to tweak lightsource geometry positions in Octane like you would in a real photostudio or reposition elements of the scene based on lighting results in the octane render.

[abstrax]

Thanks Marcus ! I appreciate the explination. I realize we're not dealing with a modeling app, I just wanted a better understanding of why octane was designed the way it was. I also realize how complicated it can be to go back into source code written with one purpose in mind and try to change something as fundamental as this !

As far as object positioning - I go back and forth between apps like Maya, ZB, Magics, FreeForm Modeling System, ect. all day long. As long as I set everything is set up properly at the start, object positioning relative to the scene or worldspace is always consistent with separate object export and import. Same with scale. I always assumed position and scale were components of standard obj export and easily translated into the application importing the geometry. I also realize Octane may have an architecture that's radically different in how it works in 3D space and what looks simple in other apps isn't in this case. I've noticed the "voxel" message on object import and wondered if the geometry isn't being completely rebuilt as a voxel volume.

The two biggest headaches I have right now are finding the desired material node to tweak (if there’s a viewport/ scene based material selection method I missed it - user error !), and adjusting light emitting objects’ position in a scene. I probably need to test render the scene first in Mental Ray to get the lightcards positioned where I want them, but it would be great to be able to tweak lightsource geometry positions in Octane like you would in a real photostudio or reposition elements of the scene based on lighting results in the octane render.

With "voxelization" we mean building the acceleration structure that is needed to efficiently trace rays. And here lies the crux: We need to change things in that area to allow placement/changing of geometry and other things. But we will see what the future brings

Regarding material selection: Use the material picker tool from the render viewport toolbar (see pages 36 and 68 in the manual).

Regarding light sources: At the moment you have to place them in your 3D app. You setup the brightness in Octane, but placement has to be done in your 3D app.

Cheers,
Marcus

[Jaberwocky]

Of course you can change the direction of the beam of light if you are using some of the IES lighting profiles even if you cant change the mesh positions within octane.

[gueoct]

Maybe i don´t fully understand the workflow.

I`ve been using octane for a few test projects until now.
In a medium size project with about 20 different materials, it took me a few of hours
to adjust the lighting and materials for the render, when i realised that one part of the
model would need some changes on the look.
if it would be very helpful to split a big scene in different parts to make it possible to replace
parts of it later.....

[Refracty]

You can reload the updated geometry. If you have assigned "stand in materials" in your 3D modelling app then it should update fine by using .mtl information.
But it still takes some time to import / voxel big scened...

I`ve been using octane for a few test projects until now.
In a medium size project with about 20 different materials, it took me a few of hours
to adjust the lighting and materials for the render, when i realised that one part of the
model would need some changes on the look.
if it would be very helpful to split a big scene in different parts to make it possible to replace
parts of it later.....