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View Full Version : Modeler viewport speed/ flat shade extremly slow! others not.



prometheus
08-23-2010, 07:52 AM
I would like to understand why the opengl rotation gets so much
slower when using the flat shade mode in modeler viewports, using a smooth shade and texture mode or any other preview works flawlessly
without slowing down.

this is on a 64 bit machine, and a 250 000 poly objects but I believe itīs the same on another computer with 32 bit.
the streaming or buffered vbo doesnīt make any difference neither the shading method.

I would be nice to figure this out.

Michael

Elmar Moelzer
08-23-2010, 07:55 AM
That is because in order to flat shade, you have to physically separate the polygons from each other. This means double (or more) the vertices. This also means that transformation quickly becomes a bottleneck.
This is why the smooth shaded views are faster.

prometheus
08-23-2010, 08:01 AM
That is because in order to flat shade, you have to physically separate the polygons from each other. This means double (or more) the vertices. This also means that transformation quickly becomes a bottleneck.
This is why the smooth shaded views are faster.


Excellent elmar, thanks
:thumbsup:

Michael

Lewis
08-25-2010, 03:16 AM
AFIR only Wireframe/Texture/Texture wire (and maybe smooth shade) modes got VBO support back then in LW 9.2 (or it was 9.3) when they speed up OpenGL massively in those modes. Rest of modes remained slow.

BenMora3D
04-09-2011, 06:10 PM
I also noticed that having the Scene Editor/Dope Sheet open significantly slows down playback.

shrox
04-09-2011, 11:55 PM
That is because in order to flat shade, you have to physically separate the polygons from each other. This means double (or more) the vertices. This also means that transformation quickly becomes a bottleneck.
This is why the smooth shaded views are faster.

I did not know that.