I'm making a small room and furniture and running into some issues lighting it accurately. Here's the problem simplified:

This wood of this drawer is all the same material, but renders in two completely different colors (the brighter color is the intended one). This happens with spotlights and area lights. The same thing happens in the full room and on higher render settings, so it's not a matter of light bounces.

It happens with other objects, too:

Again, the same material, but rendering differently. Oddly, rotating either of these props 90 degrees doesn't change which faces are brighter.

not a problem with your lighting but a problem with the shader you are using for the wood. post your material settings so we can see them.

what happens when you rotate the object so that the horizontal grain is running vertical?

ghostship2 posted at 6:10PM Sat, 30 May 2020 - #4390604

not a problem with your lighting but a problem with the shader you are using for the wood. post your material settings so we can see them.

Pretty standard PBR sort of setup:

I've used this exact shader on other things and not had this happen.

ghostship2 posted at 6:12PM Sat, 30 May 2020 - #4390605

what happens when you rotate the object so that the horizontal grain is running vertical?

No difference apart from the change in direction. The dark parts are still dark, the light parts are still light.

respectfully I'd have to say that there is nothing "PBR" about this shader. with PBR specular should be white for all non-metal surfaces. Second, PBR uses Fresnel on everything. Fresnel changes the way light is reflected based on the viewing angle. You are using two sets of bump maps or one that is plugged into two different bump methods. Try my PBR shader and see if the weirdness goes away. https://www.renderosity.com/mod/freestuff/poser-11-super-pbr-shader/82690

I was using PBR colloquially, I guess, meaning diffuse, specular, normal, and bump maps.

I tried your shader, and it worked, so thank you for that! But I don't understand why it wasn't working beforehand. Take the first image: the darker face and the lighter one are parallel to each other, so it doesn't make sense to me why light would be interacting with them so differently if they have the same material.

If ghostships shader doesn't fix the problem it might be how the faces are modeled believe it or not. I've seen things like that before, but not quite exactly, with hard surface models that are reacting badly to Poser's smoothing. Just guessing... probably shader related.

Glad you got it sorted. Shaders then.

EldritchCellar posted at 7:00PM Sat, 30 May 2020 - #4390618

Glad you got it sorted. Shaders then.

Well... yes and no. They worked on the simple scene I used to demonstrate the problem, but once I tried them in the actual scene it was the exact same situation. Back to square one.

Do you have smoothing enabled in your render settings and in object properties?

Are the models constructed with control loops or are they unwelded?

I would turn off smoothing in render settings and in properties of each effected model and see if that helps. Can't really determine without seeing a wire frame of an effected model.

I'm still not convinced that it's smoothing though, by the looks of it. I'm leaning towards some shader problem. It definitely is peculiar though. Hope you find the solution.

EldritchCellar posted at 7:27PM Sat, 30 May 2020 - #4390621

Do you have smoothing enabled in your render settings and in object properties?

Are the models constructed with control loops or are they unwelded?

Turning off smoothing made no difference. The models are standard box modelling objects; no ngons, no double verts. Part of the first object isn't welded to the rest, but this same issue affects the second object as well, which is welded.

@GMM why use a normal map and a bump map when they have the same purpose? Unhook the normal map - these are not the same as other texture maps, they are more like code and can cause trouble if not created and used properly. Out of interest, where/how are you creating the maps you're using?

The plot thickens: I've tried to replicate my earlier success with ghostship's shader in a new file and now it doesn't work like it did.

It was working:

I'm not sure I've ever seen something this bizarre in Poser.

Hmm. Well I know that if you don't disable smoothing in both render settings and properties you'll still get the shading problem I'm thinking of. It's how Poser utilizes phong smoothing... It causes specularity problems ( i.e. uneven lighting across faces) unless the models are made with control edges or each connecting face is unwelded ( an old school Poser workaround that looks terrible). Smoothing groups can also be used to circumvent this problem. I can link you to an old tutorial about it I did here on the forums ages ago but I think you've figured it out. Interested to see the solution, take care.

caisson posted at 7:57PM Sat, 30 May 2020 - #4390631

@GMM why use a normal map and a bump map when they have the same purpose? Unhook the normal map - these are not the same as other texture maps, they are more like code and can cause trouble if not created and used properly. Out of interest, where/how are you creating the maps you're using?

They have similar purposes, but not the exact same; I just like the combination sometimes.

But, this helped me zero in on the problem. I changed the Gradient Mode from Gradient Bump to Object Space, and that immediately fixed it. Thank you!

Still doesn't explain the shader not being reproducible, but that's another matter.

If you've baked an object space normal it will be tied to that geometry - it won't work correctly on any other object. You could bake/create a tangent space normal, but then the results may differ between engines as Preview, Firefly and Superfly each have a different tangent basis. If you're making a wood material that can be applied to any model and used in any engine, bump is the way to go.

gmm2 posted at 1:16AM Thu, 04 June 2020 - #4390635

caisson posted at 7:57PM Sat, 30 May 2020 - #4390631

@GMM why use a normal map and a bump map when they have the same purpose? Unhook the normal map - these are not the same as other texture maps, they are more like code and can cause trouble if not created and used properly. Out of interest, where/how are you creating the maps you're using?

They have similar purposes, but not the exact same; I just like the combination sometimes.

But, this helped me zero in on the problem. I changed the Gradient Mode from Gradient Bump to Object Space, and that immediately fixed it. Thank you!

Still doesn't explain the shader not being reproducible, but that's another matter.

As far as I know when using Normal maps in the Poser surface node (The standard one) it should be set to Tangent, also you have to make sure that the map when imported is set to gamma 1.0

If you want to setup PBR I would strongly suggest that you use either CycleSurface or the PhysicalSurface... Personally prefer the PhysicalSurface as its far easier to work with.

In PhysicalSurface you can plug in the textures directly (Diffuse, Metal, Roughness, Normal) Which will give you correct results.

From what I can see on your images it does seem like the model have some surface issues. Near the bottom drawer that you have problems with, but also on the black part below it and the wood next to it. The shading looks wrong, The black "line" and the white / light grey corner, seem to suggest that the mesh is not split correctly. (This seems to be an issue with Poser smoothing if im not mistaken.) It has to be fixed in a 3D modelling app.

(Anyway that is just what it looks like to me based on the images you posted. So might be wrong :))