PDA

View Full Version : Slower viewport when dynamics is ON



next_n00b
01-03-2019, 02:15 PM
LW=2018.07

I've noticed a slower viewport performance in Layout when "Enable Dynamics=ON". I have a scene with less than a million polygons and it is at least 2-3 times slower when I turn dynamics on. Anyone noticed this? Could be a bug?

prometheus
01-03-2019, 04:03 PM
LW=2018.07

I've noticed a slower viewport performance in Layout when "Enable Dynamics=ON". I have a scene with less than a million polygons and it is at least 2-3 times slower when I turn dynamics on. Anyone noticed this? Could be a bug?

It seems only natural that it would be slower, the system would probably like to evaluate the items in the scene.
Are you saying you do not have any object in there that is active as a bullet item? but the scene still is slow?

Anyway..it doesn´t make any sense to have dynamics on..if you do not have any dynamics, and if you do have dynamics..you shouldn´t be surprised.

next_n00b
01-03-2019, 05:01 PM
I have a scene with dynamics, but no calculation has been done yet. Rotating the prospective viewport becomes immediately slower by enabling dynamics (by pressing the button in the menu on the left). I don't see why rotating in the viewport would become slower in such a case.

Kryslin
01-04-2019, 07:45 AM
Nothing here, move along...

Jarno
01-04-2019, 03:13 PM
If there is anything enabled that can deform an object, then drawing that object in the viewport uses a slower method than drawing non-deforming objects. (In technical terms, deforming objects use immediate mode OpenGL, while non-deforming use VBOs).

We have some changes in the works that improves this situation.

---JvdL---

next_n00b
01-04-2019, 04:24 PM
Hi Jarno, I really appreciate your feedback. Based on your information, I have done some additional reading about the immediate mode and Vertex Buffer Object. I think I understand now, why it is implemented this way. Thanks for clarifying this for me!

It’s good to hear that you plan to improve the viewport speed even further. Thanks!

jwiede
01-04-2019, 05:49 PM
If there is anything enabled that can deform an object, then drawing that object in the viewport uses a slower method than drawing non-deforming objects. (In technical terms, deforming objects use immediate mode OpenGL, while non-deforming use VBOs).

We have some changes in the works that improves this situation.

You're moving to full-on "dirty-list" caching and VBO-rendering of both deformable and non-deformable geometry, I hope?

Done properly, should greatly improve viewport perf. Even if you still use immediate for "actively updating" geo, just moving all the "deformable-but-static" geo to cache & VBO should still yield major view perf. improvements.