Made a hall, that renders fine in Poser4. But when I render in Firefly, I get these strange patterns on the wall. Settings are: Production Quality, Raytracing, Shadows, Polygons, Texture Filter. Pixel Sampling = 3, Filter = 1. I used 12 spotlights in this scene. This pattern does not come from the bump map. Could it be caused by the light settings, shadows or anything else. Input much appreciated! Thanks - Walter

Attached Link: http://www.keindesign.de/stefan/poser/firefaq.html

Have you checked to make sure there were no "stray nodes" with things plugged in? I don't know how this kind of thing would happen in rendering if there isn't a node causing it, but you might be able to find an answer at the website attached. Unless this is an extension of the "smooth polygons" glitch...? Try rendering without the "smooth polygons" option checked and see what happens.

Have you tried setting smooth shading off for the geometry. This could be a smooth shading issue.

It's definitely a geometry issue of some sort, though it could be caused by smoothing, displacement, bump, or texture filtering. Can you post a wireframe of ONLY on of the affected areas, or perhaps a chunk of the areas in a new, close up render? I'd like to see the specifics of it. in general, that ballooning would be caused by smooth polygons, but shutting them off for the whole scen may not be necessary -- select that object, go to the properties tab of the dials thingy, and uncheck smoothing for that item to check. hth, ynsaen

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)

first....very nice render...well minus the defect...but great render anyway...nice effects with light, texture, and displacement.... about the defects....i get a similar trouble with single sided plane primitives (especially the vertical plane) with spotlights....the problem is when i point a spotlight at a vertical plane primitive i end up with grey and black checkerboard patterns....turning off the smoothing doesnt help...the solution i discovered was to replace the plane with a resized square primitive....the checkerboard patterns disappear if i use anything other than a plane primitive...this pattern shows up on a plane whether textured or not as long as a spotlight is used.....i wonder why.... i thinks its probably what ynsaen said about the geometry.... anyway.....i thought id mention it.....its kinda like your problem.... i guess if its possible you could replace the affected areas in your scene with a resized square primitive? or export a poser square primitive and incorporate it in your original mesh... if all else fails you can always use photoshop to cover the defects....

If I remember correctly there was a simular glitch that was a result of the texture filtering being on. Just a thought

Thanks for the discussion. It's definitely not a stray node problem. I checked that. The geometry is a simple tiled plane made in C4D. It doesn't show any problems with Poser4 or Poser5 in other places. I didn't check the smooth polygon or texture filter thing yet. Have to try it. Looking at it only areas lighted by certain spotlights are affected. I also have to play with theses lights to see if this changes something. Thanks for your input, any other idea? - Walter

Without further data, kinda hard -- you say a tiled plane, which makes me further wonder about the mesh, again. But then you also note it's a certain spotlight, so... lol

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)

Hi ynsaen,

Here is the mesh of this wall tile (taken from UV Mapper). Can't show you more deatils at the moment, because I'm not at home, but my Poser5 is ;-). Will come up with more information later.

Thanks

• Walter

I've had similar problems with this effect in FireFly. I've found that it can sometimes be cured by adding a tiny amount of displacement to the affected parts. cheers, Diolma

Diolma has it dead on, Walter. Firefly does not render single sided planes very well in certain circumstances, and also does not handle places where two flat planes slightly overlap as well. Maya had the same issue with a couple of rendering engines it was using a generation back or so. The secret is to take a math node, set it to Subtract, change the first value to 0.05, and plug it into the displacement channel, which is then set at something like 0.01 or so. This will usually make the issue go away. Hope this helps :)

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)

I made a render from another position in the hall to better see what's happening. I switched on/off all options of the firefly render and found out that it only happens, when I turn the shadowmaps on. This render is done with quality 256 set on all spots.

This was rendered with setting the quality of all spots to 1024.

In the 3rd render I turned the shadowmaps off on all spots and I used raytraced shadows. The pattern is gone, instead I get some ugly black spots. By the way, setting a displacement according to ynsaen didn't help. No change was visible. Any further idea?

Attached Link: http://www.keindesign.de/stefan/poser/firefaq.html#2

Try increasing the shadow map bias.

Were can I do that? I have a German Poser Version.

Hm...hab gerade leider keinen Deutschen Poser 5 zur Hand :-/ Wenn du in der Parameterpalette auf die Seite gehst wo du zwischen ray tracing und shadow maps wechseln kannst, gibt es dort zwei Raedchen. Eines davon zeigt Ganzzahlen an (damit wird die Weichheit des Schattens eingestellt) und eine mit 'ner Kommazahl, der Standard ist wenn ich mich recht erinnere die 0.8. Das ist der "shadow bias" Parameter, wenn du den hoeher stellst (versuch mal 1.5) sollten die Muster verschwinden.

Aha, also 'Min. Schattenverzerrung'. Warum mues deutsche Softwareversionen geben? Herzlichen Dank, ich werde es gleich versuchen. - Walter

Leider Nein. Bei Shadowmaps hilft es leider nicht. Ich habe noch immer das selbe Muster.

You don't have atmospherics enabled by any chance, do you? Try really large values for the shadow bias, like 5 or 10. What could also work would be increasing the shadow blur - that other dial. And if you haven't done so yet, read Dr. Geeps tutorial about adjusting the shadow lite cams, that can also vastly improve the shadows. (wieder in Englisch damit die stumm mitlesenden auch was davon haben.)

Habe die Weichheit des Schattens auf 5 gestellt. Pattern ist jetzt schwher, aber immer noch da. Bias hatte keinen Effekt.

OK, cross-posting. I try it with the high bias values. I have no atmospherics enabled.

Setting the Bias to 10 improves, but does not solve the problem. I'll try the Geep tutorials. What makes me a bit suspicious is, that only one of my lights seem to generate this effect. I have to check that too.

dang. I'm going to follow this thread a bit. I'm very interested in knowing what does that. And, since I was rude and forgot to say so before -- that is one awesome set!

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)

I slept a bit and did the next render. It really seems that a single spot is causing all the troubles. The now famous spot number 9. I changed the end angle of the spot and guess what. The pattern changed.

Forgot to say, changed it from 160 to 70. Thanks ynsaen for your kind words.

Very, very interesting... Any chance you could send me the light set? I'd like to look at it.

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)

Is it the spot at a weird angle to the walls? What happens if you disable "cast shadows" on the walls with the weird patterns?

Hi stewer, I think I'm gettin to the point. The spot is showing up (y-direction) and is thus placed in a 90 angle to this wall. It is meant to light a completely different part of the hall. It is more than 10 poser units away from the wall (x-direction). So this is just stray light. The pattern definitely comes from the shadow map and no displacement helps. Other spots show the same behavior, but not as obvious as this one. You have to look very close to see it. It also seems that moving this light closer to this wall the pattern gets smaller. I have to verify that. At the moment I assume that there is a bug in rendering the shadow maps. To get this effect you have to place a spot quite a distance away from a wall in an angle to the wall about 90 and a wide light angle (near 160) to get the "best" effect. I will give 'disabling "cast shadows" a try.

Ok, I disabled "cast shadow" on one wall tile (yeah, it was the left one in the back) and the pattern disappeared. Does this mean there is no shadow map calculated on this wall? What does this tell you?

ynsaen, sure I can send you the lightset. Just let me know where I can send it (via IM)

Looks to me like it's a self-shadowing effect. That's no bug in the shadow map implementation but a problem that any renderer using z-depth shadow maps has.

Any known solution or workaround? I would like to know why this only happens in some places and why only the walls are affected.

How does this z-depth shadow work? Is there an explanation somewhere?

By the way, there is no such problem with Poser4.

Ok, seems that switching "cast shadow" off helps. Switched it off on all wall tiles and the result is excellent. As you may notice, I have to switch it off on the floor tiles as well. Seems to happen only on planes. Thanks for your help stewer. Isn't that something for your FAQ ;-).

*By the way, there is no such problem with Poser4.* Yes, there is. See the picture. Even worse, in Poser 4 you don't have the shadow bias parameter that can fix self-shadowing in most situations.

Here's the same artifact in Maya 5 PLE. It's a general problem with shadow maps flat angles.

So it's not my fault, but at least there are several options to deal with it. I post an additional render I did with Poser4 render in Poser5. I didn't see the pattern there.

Well glad That at least the answer came about! I only wanted to see the light set so I could maybe come up with a workaround that keeps the basic lighting system for you and to analyze the issue more closely. If Stewer's points help out, then groovy!

thou and I, my friend, can, in the most flunkey world, make, each of us, one non-flunkey, one hero, if we like: that will be two heroes to begin with. (Carlyle)

Well, thanks anyway. Don't know how many are still following us. This was the last blocking point for my project. Just have to do the documentation and up to testing it goes. Thanks for all your help - Walter

Quote - Diolma has it dead on, Walter. Firefly does not render single sided planes very well in certain circumstances, and also does not handle places where two flat planes slightly overlap as well. Maya had the same issue with a couple of rendering engines it was using a generation back or so. The secret is to take a math node, set it to Subtract, change the first value to 0.05, and plug it into the displacement channel, which is then set at something like 0.01 or so. This will usually make the issue go away. Hope this helps :)

marked

JD Wohlever
Techware 3D

pity there isn't a way to bookmark a thread without bringing it back to the top of the forum

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Actually, LOL I just found a way.. At bottom of message before the Reply body hit the SUBSCRIBE button... DOH!

JD Wohlever
Techware 3D

thats good :)

..but  a shame too as I was curious about what other threads may be revived from the dead

 

I've found the best way for saving is to use the favourites folder in IE,I've got material threads saved in one folder,lights & cameras in another..etc,etc

this thread is over 2 years old & I doubt its still being replied to so subscribing isnt much use

 

Cheers

Stefan

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