Ryan-M

Technically speaking, every ray is a reflection ray that contributes to GI. Specular reflection is as much a part of GI as Diffuse reflection. Do you mean specular rays traced from zero-roughness surfaces? What about shiny metal with a low but non-zero roughness? What about through rough translucent materials? There isn't a clear line between when you'd want to apply the HDRI and when you'd want to apply the color. I'm not necessarily opposed to figuring something out, I just think it's a bit vague and will either produce results that not everyone is content with or will involve arbitrary thresholds or goofiness that cause materials to respond dramatically differently when they shouldn't.

Currently, no. This is something that I've looked at and I ran into enough questions I didn't have a great answer to that I shelved it. For example, what constitutes "illumination"? What do you expect to see through the window? What do you expect to see in window reflections? What do you expect to see in a mirror reflecting a window that you can see the backdrop through? If you're just interested in a toggle that says "for pixels not occupied by anything else, display the backdrop" and uses a solid color for all lighting calculations then that's one thing, but I wasn't convinced that would really satisfy people. Please do share them, I'm very interested in what kinds of things could make using the renderer simpler to use or produce better results for someone's use-case.

The top of the dialog allows you to configure how the fixture should produce light. "On in Default Light Set" basically turns the light on in the default light set (so the light will cast light in any views using that light set). We don't disable the punctual lights even when using an area light for a couple of reasons: The punctual lights can be used to configure the power output of the fixture (e.g. when "Apply Emissive and Color from Light(s)" is checked). Area lights are only used in Ray Traced PBR views. The punctual lights are still used in all other views. We don't generally disable user interface in dialogs like this in a way that is dependent on the view the dialog was opened from. There is a lot of complexity added to the dialog due to it needing to facilitate non-PBR techniques, hardware that doesn't support ray tracing, etc. Yes. You can think of "On in Default Set" as "can potentially cast light in the default light set", where part of the criteria for satisfying that potential is whether or not you're in Ray Traced PBR and the fixture is set to Use Area Lights. The purpose of automatic exposure is to allow you to move the camera around and/or between lighting environments without needing to reconfigure exposure settings. It simply tries to keep the output within a reasonable/viewable range as a function of the overall intensity of the rendered scene. You are correct that it can make it difficult to "correctly" calibrate lighting. If you're tuning a particular scene and your camera is static, then manually configuring exposure makes a lot of sense. Backdrop intensity values are interpreted as Luminance.

Area lights and punctual lights on a single object are never used simultaneously. If the "Use Area Lights" checkbox is checked (it is by default) then the emissive surfaces on the fixture produce light. If it is not checked, then the punctual light sources produce light. Punctual lights specify lumens which quantify total power output. Emissive materials specify power per area (e.g. candela/square meter). This makes it generally more difficult to work directly with emissivity. An emissive material applied to a small bulb will produce significantly less light in your scene than the same material applied to a large bulb. We wanted to allow people to continue to work with lumens. The "Apply Emissive and Color from Light(s)" checkbox allows the emissivity of the emissive material(s) on a fixture to be derived from the lumens specified in the punctual lights on the fixture. If you have a fixture with a single point light that produces 1200 lumens and the "Apply Emissive and Color from Light(s)" checkbox is checked, then Chief will automatically calculate the appropriate emissivity of the emissive materials on the fixture such that all of the emissive surfaces on the fixture output a total of 1200 lumens. The point light itself won't cast light, but its intensity (and color) will inform the properties of the emissive surfaces that make up the area light. When "Apply Emissive and Color from Light(s)" is checked, Chief uses the sum of the punctual light sources on a fixture as the means by which you dictate the total power output of a fixture. When you uncheck that box and directly configure the emissivity of a material you're no longer working in lumens, and it is correct that you will have to specify values much larger than typical lumen values in order to get the same results. In general, I would recommend leaving that checkbox checked.

3D grass is not supported in CPU ray trace views.

Are you asking for something like an added area light (where it produces light but isn't necessarily a visible part of the model), or just the ability to more easily create area lights of basic shapes? Can you do the work to create an emissive face/rectangle with a specific orientation once and then add it to the library for future use?

The pixelation through the windows in your first two images look similar to an issue that we addressed in the 26.2 release. I believe you can still get it to happen, but my understanding is that it will only happen if your plan is very far from the origin so that might be something to check. In your last image with the water, it looks like poor denoising (on the water itself). X16 sometimes struggles to remove noise on transparent (refractive) surfaces. We expect this to be improved in X17.

You are not the only one and we have contacted AMD about this. For now, rolling back to an earlier driver is the appropriate solution to the problem.

We have reproduced this on specific laptops with switchable graphics. The only way we have found to work around it is to disable the Intel card on the machine. The safest way to do this is via the HP Omen Gaming Hub software. Steps may vary depending on your specific machine, but I've attached images illustrating the process that works on the machine that we have. Specifically, you want to switch from the Hybrid GPU mode to the Discrete GPU mode.

In the context of ray tracing, we have seen performance scale approximately linearly with core count when comparing the same tier of hardware. A 12-core M2 will be about half as fast as a 24-core M2. A 12-core M3 will be about half as fast as a 24-core M3. There is a fairly significant jump from M2 to M3 (for example, a 12-core M3 is more than twice as fast as a 12-core M2) due to the introduction of dedicated ray tracing hardware. The most powerful M2 Studio probably isn't going to perform better than the most powerful M3 MacBook Pro when it comes to ray tracing. I can't speak as much to non-rendering performance as we don't really have similar benchmarks. It is comparatively simple to benchmark ray tracing performance in Chief. Outside of that, there are so many unique operations with different performance characteristics that it would be difficult to quantify in the same way.

Yes. This is good to know, we don't have that card in-house.

I believe the original benchmarks were Nashville, Kitchen 1 at 1400x860 (don't ask me why, we were profiling the Mac at the time and I'm pretty sure this was the resolution I got by default on an MBP). Please bear in mind that the numbers Trent posted were from a specific build relatively early on in X16 and that exact samples/sec in the current version may have changed somewhat since then.

In my recent benchmarking, a desktop 4070 was about twice as fast as a desktop 3070, and a desktop 4090 was about 2.2x faster than the 4070. This was tested in a specific plan at a specific resolution so results may vary a bit, but in general I would say that a 40-series is a significant improvement over the 30-series.

This is cool, thanks for sharing. Adding more variety to the grass tool (and expanding it to other types of similar foliage) is something we've talked about a lot, and these are good examples of what it could do.

It causes the view to stop rendering when it reaches the specified number of Max Export Samples. In X15 the view will denoise at this point. If it's left unchecked the view will continue to render indefinitely.