Poser 9: Certain faces not rendered if render size greater than preview window?

3dcheapskate

I'm having a problem with the face of the shield in this render. Under certain circumstances the faces on the front of the shield are simply not rendered.

Originally I thought it was camera related - hither/yon, the shield being too close to the camera, etc.

However, I've now got the problem repeatable and it appears to be a render size issue!

I'm using Render Settings > Render To Exact Resolution. But strangely the problem appears to be related to the preview window.
If I set a render size that fits into the preview window it seems to always render successfully.
However, if the render size is larger than the preview window I seem to always get the problem.

Any ideas?

(150x250 and 384x512 successful renders, plus a cropped aborted 768x1024 problem render attached)

WandW

Are you using depth of field? If so, does it render successfully with it off?

3dcheapskate

Yes, I'm using depth of field. I've just done a couple of test renders to check, but that doesn't appear to be the cause. I get the same effect with dof on or off - renders attached.

WandW

I'm grasping at Straws here, as I've never seen that, but I have PP2012, not Poser 9. Did you install the service release...

http://poser.smithmicro.com/poser9-updates.html

3dcheapskate

Yes, I'm using 9.0.3.23027 - just rechecked. Many thanks for the suggestions. Hopefully somebody else will have some more - in the meantime I'll try posting the query over at Renderosity too.

3dcheapskate

Just noticed another thing that might be a clue. I let one of the 768x1024 renders complete - attached is a crop from it.
The studs on the front of the shield (which are separate geometry) seem to be rendered correctly,

WandW

The bottom corners seem to be rendered too. Very strange...

3dcheapskate

Found it! It's the displacement. The shield face uses displacement and the problem only occurs if Use Displacement Maps is checked (first image). If it's unchecked then the render's okay (second image). I was convinced I'd already checked that? Just goes to show... always double (and triple) check everything!

A bit irritating, but I can just use bump instead for this render.

The (rather academic now) question that remains - "Why?"

3dcheapskate

WandW said:

The bottom corners seem to be rendered too. Very strange...

That's why I originally thought it was camera/hither/yon related. Move the camera a bit further back and the part of the shield that renders correctly reaches higher. I'd completely overlooked the studs every time I looked at the problem!

A fresh day and a fresh pair of eyes... :)

Lissa_xyz

Check the min displacement bounds option in your render settings. I read somewhere that the number in there has to at least be the total of your displacement settings from the mat room, or something like that (for instance if you had 4 mat zones, each with a .5 displacement strength, then you would plug in a 2.0 in the render settings option).

3dcheapskate

Vaskania said:

Check the min displacement bounds option in your render settings. I read somewhere that the number in there has to at least be the total of your displacement settings from the mat room, or something like that (for instance if you had 4 mat zones, each with a .5 displacement strength, then you would plug in a 2.0 in the render settings option).

You're right, badly set up displacement (bounds and other settings) was the problem - I got some fairly detailed pointers from aRtBee over on the Renderosity thread. Not completely resolved, but well on the way I think - part of my 768x1024 render, as before but with more reasonable displacement bounds settings, attached. Still not right, but definitely on the right path.

Lissa_xyz

I wasn't used to seeing a setting like that and went digging for what it was and came across that tidbit of info. Still not sure how exactly you calculate it for a complex scene. Who wants to go through each mat zone adding displacement values for a scene with like 30 objects? Sure as hell not me. lol

/edit
Aha! Found a bit more:

(This greatly effects the usefullness of the displacment settings. The value here should be a bit greater then your highest displacement setting used in the material room)

I guess you put a bit more than your highest disp value, not a total of all of them added together.

http://poser.smithmicro.com/tutorials/render_displacement_map.html
Looks like it was for P5, but it should still be valid.

.. and another quote from Baggins back in 2007:
It is better to use the max displacement bounds on a single figure or prop and leave the global one at 0. That way, it only goes through the extra effort where needed.

http://forum.runtimedna.com/showthread.php?28990-Displacement-distance-computing

3dcheapskate

It's definitely worth taking a look at the advice I got over at Renderosity, and the bit in the Poser Reference Manual, Chapter 37 Firefly Renderer Settings with the picture of the pyramid (it's definitely there in the Poser 6 and 9 manuals)