Possible ray traced reflections / softshadows bug ?

[Chinaski]

Hi all,

I'm working on a scene with an imported object. Here's a test render of an object with multishader material:



As you can see, one subobject texture have a reflective shader with actived ray traced reflections option. Objet render is pretty good, but shadow render (center of image) is strange. This bug appears only when softshadows are actived.

Here's a screen of my nodes network:



That's a know bug or I'm wrong with nodes configuration? I'm using technology preview version of TG2.

[zionner]

Well, I think your best bet is to first, try increasing the number of soft shadow samples, and if that dosent work then try changing your lighting position


If it still dosent work...then I'm sure someone else here can help you.

[dhavalmistry]

yes I think it has to do with shadow samples..

[zionner]

should of mentioned this before:

What are your Sample Settings?

[Oshyan]

It looks like a shadow or GI bug more than a reflections issue. Does it go away if you turn off soft shadows?

- Oshyan

[Chinaski]

Ok guys... Some others renders :

First, same scene, no softshadows, sun at 40° elevation, two centered objects with reflective shader (raytrace and no raytrace):

No bug.

Same scene, softshadows turned on (1°, 20 samples), centered objects with reflective shader (raytrace and no raytrace):

Bug.

Same scene, softshadows turned on (5°, 20 samples), centered objects with reflective shader (raytrace and no raytrace):

Bug.

Now an other scene, same global settings, same nodes configuration (defaut shader -> reflective shader -> multishader -> object), but external nodes this time, no imported object but 2 spheres:

One sphere with reflective, simple shadows: No bug; one sphere with reflective, soft shadows: No bug; one sphere with reflective and ray traced option, soft shadows: No bug; two spheres with reflective and ray traced option, soft shadows: No bug; two spheres with reflective and ray traced option, soft shadows (more samples, more degrees): No bug. Can't reproduct it.

So I think bug appear only with reflective shader on imported objects, maybe just my imported object, maybe just on my computer. Some others renders are running with an other imported object. Is there a way to product same effect (raytraced reflection on a sub-object material) with an other nodes configuration?

[Oshyan]

Strange. I wonder if there is something odd with the geometry (normals, for example). Do you have "Use smooth normals" turned on? Can you try with a simpler exported object with the same materials/setup?

- Oshyan

[Chinaski]

Just a cube (object here) this time:



Same result with smooth normals turned on and turned off. Same thing with double-sided surfaces and flip normals.

Maybe I'm doing something wrong. I'm building mesh (and doing materials definition) in 3D editor (Max, old version), export 3ds format, import in PoseRay for conversion, export obj format, import the obj in TG2, and modify my material in the internal network (clipfile here). Or this is just my old pentium III workstation who can't compute reflections and soft shadows.

[zionner]

Yeah, looks like samples to me..

Try changing your softshadow samples to 34

[Chinaski]

And I think you are wrong.

Same object, same light settings, same softshadows settings (samples 25)... Just a difference: no reflective shaders on left, reflective shaders on right.



Can you see the difference?

By the way, I'm working with a complex object (81000 faces) on a pentium III computer, the rendering time is two hours (without reflective shaders, nothing else in scene for now), I can't do better than 25 samples.

I don't know if it's a TG2 bug (reflective shader/softshadows/internal network/something else.), a mesh or normals bug, a texture bug, a computer bug, an user bug... But I'm almost sure that's not the shadows samples.

[Seth]

i don't think it's sample settings...
it's far too odd... but i am not a specialist though.
Chinaski did a lot of test before posting this bug here and i think he would have found the solution if it was only sample related
but i may be wrong...

[Oshyan]

The interaction of reflection settings here is interesting and I think it's probably the key. The reflection system is being redone for the final release so this sort of thing should be tested once the beta is available and if it's still present it's a bug we'll need to fix.

- Oshyan