It's very safe to say that it is normal, because Maxwell is an unbiased renderer; barring the remote possibility that you are looking at an actual bug, we can say that if light is reflected somewhere, it is because in the real world, that's where it would be reflected. If it wouldn't seem to be, then it's fairly safe to guess that this is due to the use of unrealistic material values -- for example, a floor or countertop that has a purely reflective surface, when in reality it would have roughness to break up its reflections. However, this does not apply to glass, which is as close to purely reflective as you will find; in other words, what you are seeing is not likely to be due to your glass material.

That is the guesswork, and how things work in the absence of fakery applied for artistic purposes. I can think of a couple different ways to get rid of reflections; globally, you could disable Output > Illumination & Caustics > Direct Reflection. That would affect the whole scene, and likely yield a visibly-unrealistic result.

Another method would be to select the ceiling and enable Object Properties > Maxwell > Hide from GI. This will cause the ceiling to be ignored in the global illumination calculation, which means light would pass through it, so depending on the model, it may in addition be necessary to duplicate the ceiling, disable Hide from GI on the duplicate, and move it up just a bit. The point is that the camera will be looking at a ceiling that's not participating as normal in global illumination, but light coming in from outside will still be blocked, by the duplicate ceiling.

Other such fakes may be possible, as well, but they are not coming to mind at the moment. And, if the root cause is indeed the use of overly-reflective materials, the preferable approach would be to bring those materials into line, such that any reflections on the ceiling are not striking your eye as being out of place.

As far as posting images, it is necessary to upload them somewhere like imageshack.us or flickr, and post links to them between [img][/img] tags.
Yes, it would be viewable to anyone, but that's the only way to do it. If you don't want to do that, you can send an image to me using jeremy [at] nextlimit [dot] com. There should be no need to render full size, just to show this effect happening, but on the other hand, it's likely that upon looking at the image, the next thing I'll do is ask you to send me the model, so I can take a look at the materials, and how light is bouncing in the scene.
Just sent a zipped file connected to google drive. I scanned the file before attaching it to my email. Thanks JD! I had a problem saving files to rhino so hopefully they open okay for you. Please let me know if you have received them. The kitchen is created in chiefarchitect x8. JD do you need the mxs file?
Thanks, that clarifies things a bit, and I can make a few comments. The first thing is that it is very important in Maxwell to make sure and model things at a realistic scale -- the house in your model is only about 300mm wide. This explains why in your images, you are having some difficulty getting the camera focused, and also why things are looking like miniatures. Assuming this isn't what you were going for, that is.

Second, on the windows reflecting in the ceiling. It is a combination of a couple factors; one, that the ceiling material is a Rhino material being auto-translated by the plugin, and ending up too shiny. I would recommend right-clicking in Scene Manager > Materials, and choosing New Extension > Opaque. This will create a new Maxwell material that uses the Opaque extension, which is a simplified type with only a few parameters; set the Color as you like, and Shininess and Roughness to, say, 20% and 60% respectively. You will see that this breaks up the reflections on your ceiling; just play with the Shininess & Roughness until you are simulating something like the real ceiling finish.

Another factor, though, is that there is no ground outside this house yet, which means that light is shining up from below, in a way it never could in the real world, through the window, and reflecting off the ceiling into the camera in an exaggerated way. You want to create some exterior, at least a plane to represent the ground, more like what you'd have in reality.

Next, regarding the glass, the material you are using is a real physically-correct glass material (also referred to as dielectric). This is great for accurately rendering glass, but it is unnecessarily CPU-intensive for use in windows. In some cases, it is unnecessary to have window panes at all; take this shot for example, with no interior light, in order to see much of anything, you have to crank up the camera's exposure to the point that the windows will be completely blown out. That would be the case in real life, the same as it is here in Maxwell, and the result is that you are paying a CPU cost for something the camera will never perceive: reflections of objects on the interior of the house, from the inside of the windows.

So here, you can probably get by with just hiding the glass panes entirely; in other cases, you want the interior reflections, and there, you would likely prefer to use the Maxwell AGS material type, which is best physically described as a mixture of a mirror and vacuum; it is a material that reflects, but which does not refract, like real dielectric glass does. This can render much quicker, since it is the refraction that uses the most CPU power; you can't use it to render a glass paperweight, since the entire look of such an object depends on refraction, but for thin glass panes, you would be hard-pressed to perceive the refraction at all.

Lastly, I notice that rather than use the Constant Dome environment (Scene Manager > Environment > Type) you may prefer to switch to using either the Physical Sky, with the sun enabled, or an Image Based environment. The Constant Dome environment is just a plain color dome surrounding and illuminating the scene; this can be good for product shots (that is why it is the default in the Rhino plugin), but it's more rarely useful for architecture.

I hope you find this feedback to be useful.
You can create an AGS material similar to how I described for the Opaque one -- right-click in the Materials list, and choose New Extension > AGS.

Just to explain a bit about why it is called an "extension", in Maxwell there is only one type of material, composed of layers containing BSDF and other components; when you use one of the extensions, what is happening is that you are presented with a very simplified set of parameters, which at render time, are used to create a normal Maxwell material. I mention this because extensions can also be used to explore how various types of materials are created; when you have, for example, a material using the AGS extension opened in the plugin's material editor, and you right-click on the node for the extension (in the tree on the material editor's left side, just below the preview image), you will see there is a "Convert to Custom" menu item; clicking this, the same translation to standard material will be performed, and you'll see a series of layers, BSDFs, and so forth, which would otherwise have been created only at render time. It is worth mentioning that this is strictly a one-way conversion, since it's not generally possible to infer a simplified set of parameters, given a collection of layers, BSDFs, and so forth; you can only go in the other direction.

Regarding your question about the appearance of the texture on your appliances, it is not possible for me to say, because I am missing the "flake_noise.png" image used by the "CARpaints_6020_Chrome Green" material. However, looking at the texture in which this image is used (it appears only to be used in the Paint > Base Flakes > Angle map), I see that this texture uses "Meters" for its Units, and that the Repeat values are set to 0.5, which means that each repeat of the texture will end up being 0.5m tall & wide, and that means that whatever small dots are likely depicted in "flake_noise.png" are being mapped onto your geometry at much too large a size, given that the entire house was only 300mm across. If this is the case, it can be helped by using Relative Units in the Angle texture, and/or by scaling the model to a more realistic size.
bkjernisted wrote:JD thank you very much for your terrific explanations! I will send you a picture of my render in the morning. In the material editor under ags options for my glass, what does putting a tick mark next to Opacity/Mask do? What happens if you don't put a tick mark?
If you are seeing Opacity/Mask, I assume that you created an AGS Extension (also referred to as "Material Assistant" in the main Maxwell documentation) material, and then used the Convert to Custom option. If so, what you are looking at is one way to make an AGS material from scratch, which involves a single BSDF (it gets named "bsdf" in the conversion, and has a square black "B" icon), in a single layer (it gets named "AGS" in the conversion, and has a "folder" icon).

Since you are asking these questions, I would recommend reading through the Maxwell materials documentation, especially beginning with the BSDF topic (here). In doing so you will find that the BSDF that was created for your AGS material basically describes a perfect mirror: it has zero Roughness, a relatively bright achromatic Reflectance 0 color (RGB197, 197, 197), and an Nd (just a more specific way of describing Index of Refraction) of 20.

That said, we come to the Opacity/Mask that you asked about; if you left the original AGS parameters alone before converting the material to custom, Opacity is set to 12, and this value will be used to determine the opacity of all BSDFs contained in the layer. The checkbox will only have an effect when a Mask texture has been assigned, by right-clicking the black & grey "checkerboard" button, and assigning an image file. A Mask texture is expected to be a black & white image, and the way it is used is that each pixel's value, considering black to be 0%, and white to be 100%, will be multiplied by the given Opacity value, to determine the opacity of the layer where that pixel is mapped on the object to which this material is assigned. So, for something like glass or AGS, a Mask texture would rarely be used.
bkjernisted wrote:JD when I created the ceiling material and applied it and then rendered by tongue and groove ceiling disappeared. What did I do wrong? Thanks
It is not possible for me to say, without more information, there are too many potential factors (texture mapping, material setup, etc). In the file you sent, there were only two Maxwell materials, there were no textures included, and the ceiling had a smooth green Rhino material assigned (named White Tongue & G); that material had a texture named "WHITET~1.PNG" assigned to Object Properties > Material > Basic Settings > Color, but the texture was not included. It appeared to be this way on your machine as well, judging by the rendered images, where the ceiling has only a smooth green material, except for the cove, which in the file had a "Cherry 2" Rhino material assigned, with a missing "BOIS-0~7.JPG" Color texture.
I went back into chiefarchitect and changed the roughness to 60 percent. Now I get light on the ceiling instead of a window reflection. At the start of the render it is hard to see the tongue in groove where the light is on the ceiling, but the tongue and groove is clearly visible further back from the windows. In the last thread where I said that the tongue and groove disappeared , that may not have been the case. I was looking in the bright area and not further back. I will send you the new file in a while and a render picture in the morning. Thanks again!

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