Blender instances "patch" for the unofficial exporter

[ROUBAL]

@Matej : Thank you for the node example. I will try that.

Nodes use is not much explained in the manual, and nodes in Octane are rather different and more confusing than nodes in Blender (I have no difficulty with nodes in Blender).

About your example, the obj of the tea pot has one material only, while my Routemaster bus has dozens of materials. I am not sure that it is doable with the Material Map node without using more nodes.

For me, nodes are interesting to build some special materials, instances, and saving materials settings of an obj for reuse. But in most cases I don't need them. As my scenes are almost always very heavy, using nodes for each material would lead soon to a completely overcrowded screen. If you look at the obj node of my bus, you will see that it doesn't even fit in the width of my wide screen. This often occurs on my projects, even if I reduce the left and right panels to give more room to the nodes graph !

[kavorka]

@Roubal:
I was wondering about the materials on your bus. Do you really need that many? How many textures are you using? Are you close to the 32 max? If so, you might want to combine some materials/textures and use alpha maps to place textures where they need to be.

[ROUBAL]

Alpha maps are not necessary and would mean more images. I use my own method. The color of the bus in areas without UV is taken from a sample image of 2x2 pixels. This color is the exact color of the background of my main texture map. Taking the color directly from the main map would be possible but would require a complete UV unwrapping of the bus, that could be very tedious and messy. A procedural color is the simples and most economical way, and can also be used to avoid this 2x2 image if required, but I used the image sample because I can't get easily the exact color in the color mixer of Octane (seem to not match photoshop Hexadecimal value).

I use very few textures (less than 10). Individual textures are necessary for tileable textures like the front grille, or complex like the platform floor or the advertizing billboards. Most of the textures of stickers, plates... are on the same 2048x2048 image on which I use every smallest surface available. Textures are very optimized on this project as the bus will be integrated in a city scene, it is most important !

Here is a reduced image of the main texture with used UV areas shown.

I will use smallest spaces to add some details like screw heads or small stickers.
A high resolution is required (2048x2048 may not be enough) because I want to render in 8000x4500 at least for posters.

[kavorka]

Ah, ok. So you put several textures into one texture and make sure your UVs match up, thats what I figured. But, why so many materials? you could have all the parts that use a single texture to be the same material.
Might not work for everything, but it seems like you have soo many material nodes coming off that bus.

[ROUBAL]

Sharing textures is not enough. Every part with same texture has not same specularity, or some have bump and other have not... so I really need as many materials or almost as in real world.

It is not yet obvious, but the inside is modelled and textured as well ! This bus is intended to be seen from every possible point of view, even in close up.

[kavorka]

Sounds like a large project

[vinz]

Many Thanks Matej.

I've made a fast try, and it works really well ! ^^
Probably a stupid question, but do you have a solution to export strands hair from blender ?

vinz

[matej]

Nice test!

do you have a solution to export strands hair from blender ?

I have an idea (basically generate geometry at export), but it would require some amount of work and I don't have so much time for this right now.

[vinz]

Nice test!

do you have a solution to export strands hair from blender ?

I have an idea (basically generate geometry at export), but it would require some amount of work and I don't have so much time for this right now.

Thanks Matej,

I understand well, but what you've said is giving to me the hope that it is possible...
someday someone who have time and skills will do it, for now i will continue using ugly tricks.

vinz

[ROUBAL]

I think that strand hairs are not like grass blades. They are all individually differently combed, so there are imho two problems to solve :

1 - The geometry export.

2 - Instances could not be efficient, because each air fiber is different and the instance file could be as heavy as the original geometry description in the obj...

What do you think about point 2 ?