Itoo Software Forum

Author Topic: Strange FP Render Issue  (Read 5458 times)

Mike Truly

  • Full Member
  • ***
  • Posts: 115
    • Truly Media
Strange FP Render Issue
« on: March 10, 2009, 04:52:48 PM »
Carlos,

I am having a strange problem with FP rendering on a current project.  (MAX2008_32, scanline)

I have a scene with lots of FP trees in it.  It is a view from the air looking towards the horizon with trees in different areas.  As it happens... there are clusters of many trees that are far off in the distance and fewer trees up close.  As the frame is rendered, it renders the upper 75% of the frame in about 10 seconds... but then hangs for a long time on the last 25% (where fewer trees are!).  (Attached is an image that shows a render in progress and it is at the hang point).

The first 75% of the image renders in 10 seconds but the entire frame ends up taking 1min 55sec to render!  I tried removing the other complex objects that are in the scene in that area and they are not affecting the time.  When I removed my FP trees... the frame renders in 3 seconds.  There is something about my trees in this scene that is causing this slowdown.

I tried to save out a scene containing only the trees to send to you but when I did this... the trees-only scene renders in 20 seconds!  So I don't have a scene I can send that shows the problem.

Any ideas what may be wrong?

Thanks!
Sincerely,

Mike Truly
----------------------------------------------------------------
Truly Media
1.800.829.4990
http://www.trulymedia.com

Mike Truly

  • Full Member
  • ***
  • Posts: 115
    • Truly Media
Re: Strange FP Render Issue
« Reply #1 on: March 10, 2009, 05:30:53 PM »
Oh and I forgot to mention... this is using FP2.  (It's an older project that was originally setup using FP2 so I didn't bother redoing the setup for FP3).

Thanks!
Sincerely,

Mike Truly
----------------------------------------------------------------
Truly Media
1.800.829.4990
http://www.trulymedia.com

Mike Truly

  • Full Member
  • ***
  • Posts: 115
    • Truly Media
Re: Strange FP Render Issue
« Reply #2 on: March 10, 2009, 06:29:06 PM »
OK... this is really bizzare.

I made only the FP trees visible and it renders without hanging in 22 seconds.

Then I made the visible objects just the ground object and the FP trees only.  It hangs during render and takes 1:48 to render the frame.

This ground object is merely a large flat plane like object (it's not a plane but a mesh with a bit more detail... but nothing fancy).  This object renders in 2 seconds when the FP trees are hidden.  This ground object has a multi-level falloff material but other than that there is nothing complex about it.

There is some interaction happening between the ground object and the FP trees that is causing this.  Unfortunately, I can't find what it is and turn it off.
Sincerely,

Mike Truly
----------------------------------------------------------------
Truly Media
1.800.829.4990
http://www.trulymedia.com

iToo

  • Administrator
  • Hero Member
  • *****
  • Posts: 3319
    • iToo Software
Re: Strange FP Render Issue
« Reply #3 on: March 10, 2009, 06:30:50 PM »
Mike,

Try converting the trees to editable meshes, and if you are using Planes Material apply a Standard mat. instead. This don't solve the problem, but may help to know what is happening.

However, 20 seconds is a lot of time to render a few trees in scanline. If you like, send me the trees scene, perhaps i would find something.

Carlos Quintero
iToo Software

Mike Truly

  • Full Member
  • ***
  • Posts: 115
    • Truly Media
Re: Strange FP Render Issue
« Reply #4 on: March 10, 2009, 07:05:17 PM »
Carlos,

Thanks for the ideas.  I am using a standard material on the FP trees.  I converted the FP trees to an editable mesh and the render time dropped to 30 seconds for the whole frame.  (There was still a hesitation at the same hang point as before but it then continued on and finished in 30 sec).

I can't share the actual file that shows the problem but I have attached a simplified scene of just the trees and ground (and other items).

I also tried changing the material on the ground to a plain gray material but this did not affect the long render time of the FP trees.  The FP trees use a custom mesh object (which is really just a 3 plane tree) and I tried changing it to a 2 plane tree but it didn't really affect the render time very much.

Thanks!
Sincerely,

Mike Truly
----------------------------------------------------------------
Truly Media
1.800.829.4990
http://www.trulymedia.com

Mike Truly

  • Full Member
  • ***
  • Posts: 115
    • Truly Media
Re: Strange FP Render Issue
« Reply #5 on: March 10, 2009, 07:06:01 PM »
Oh, and also I have been rendering frame 6309 in that animation as my test frame.

Thanks!
Sincerely,

Mike Truly
----------------------------------------------------------------
Truly Media
1.800.829.4990
http://www.trulymedia.com

iToo

  • Administrator
  • Hero Member
  • *****
  • Posts: 3319
    • iToo Software
Re: Strange FP Render Issue
« Reply #6 on: March 10, 2009, 08:54:01 PM »

Unfortunately, i cannot to reproduce the problem. Forest object seems correct, frame renders in 14 sec., almost identical time converting it to mesh.

I have not some plugins used on the scene (see screenshot), i'm not sure if result would change with them.

Before to convert Forest to mesh, are you setting Viewport Simplification Level to 0 ? I want to be sure that the resulting mesh is the same that created by Forest...

Carlos Quintero
iToo Software

Mike Truly

  • Full Member
  • ***
  • Posts: 115
    • Truly Media
Re: Strange FP Render Issue
« Reply #7 on: March 10, 2009, 09:11:24 PM »
Carlos,

Those plugins are for RPM (RenderPassManager) and Cebas FinalFlares.  RPM Material is a special material to be changed for each pass when using RPM.  The ground object original material is an RPM material... this is not the problem because I tested by assigning a regular material to the ground and it did not fix the problem.  Cebas FinalFlares is for some lensflares that are in the scene... don't think this matters for FP trees.

When I did my test of turning FP trees to editable mesh... I only had simplification level set to 1, not 0.  But even so, turning the FP trees to a mesh fixed the problem and made rendering much faster.

The project is almost complete so at this point, I can work around the problem.  Clearly seems to somehow be related to when FP is dynamically creating the trees at render time since mesh trees render fine.  But the FP dynamic trees render fine too... if the ground object is hidden at the same time.  But this render problem only happens in the real scene file (and I can't share that and when I try to make a simpler file... it doesn't show the problem).  Oh well... I will keep an eye out for this problem in the future and perhaps it will not happen in FP ver3.

Thanks again.
Sincerely,

Mike Truly
----------------------------------------------------------------
Truly Media
1.800.829.4990
http://www.trulymedia.com