Author Topic: Rocket Engine  (Read 185 times)

Patrice Terrier

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Rocket Engine
« on: July 03, 2019, 06:33:51 pm »
Patrice
(Always working with the latest Windows version available...)

Michael Lobko-Lobanovsky

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Re: Rocket Engine
« Reply #1 on: July 03, 2019, 07:56:46 pm »
Hehe no Patrice,

Your .OBJ model has serious defects in Engine2 mesh UV mapping.

Below is a better version exported from the original .FBX loaded in Blender.

Enjoy! :)

(Note: Wavefront Object glossiness is the inverse of PBR roughness!)
Mike
(3.6GHz Intel Core i5 Quad w/ 16GB RAM, nVidia GTX 1060Ti w/ 6GB VRAM, Windows 7 Ultimate Sp1)

Patrice Terrier

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Re: Rocket Engine
« Reply #2 on: July 03, 2019, 08:46:38 pm »
Thanks!

As i said, that was a rough/quick translation, but the resolution is too low to spend time on it.
Patrice
(Always working with the latest Windows version available...)

Michael Lobko-Lobanovsky

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Re: Rocket Engine
« Reply #3 on: July 03, 2019, 09:48:37 pm »
... the resolution is too low to spend time on it.

This is evidently due to the original FBX using dynamic tessellation of curved surfaces that the OBJ exporter translates into editable polies too coarsely. It is a typical deficiency of cheap and careless OBJ exporters; they translate Besier control points into poly vertices literally rather then accept the user's parameter to set how smooth the interpolation between the control points should be (i.e. how many polies the user wants the curved surface to be approximated with).

See below how Autodesk's original FBX Review viewer interprets the curves. The top screenie exemplifies literal translation of control points, the bottom one, smooth interpolation between the control points.

Funny that the Wavefront Object Specification allows both Besier curves and NURBS surfaces to be encoded precisely in the OBJ files. ;)
Mike
(3.6GHz Intel Core i5 Quad w/ 16GB RAM, nVidia GTX 1060Ti w/ 6GB VRAM, Windows 7 Ultimate Sp1)

Michael Lobko-Lobanovsky

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Re: Rocket Engine
« Reply #4 on: July 03, 2019, 11:25:03 pm »
And that is all very annoying indeed! :(

Controlled tessellation was invented in the 20th century. Even I, then nearly illiterate in 3D, was able to implement it in immediate OpenGL in my naive Quake III renderer code written in an ancient version of FBSL BASIC!

What can I say about Blender's FBX-to-OBJ exporter written by modern Generation Z eggheads in the year of 2018?! @#$%^&! >:(
Mike
(3.6GHz Intel Core i5 Quad w/ 16GB RAM, nVidia GTX 1060Ti w/ 6GB VRAM, Windows 7 Ultimate Sp1)