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100

The trouble with this is that you need light to "bend" in a continuous arc around the black hole. The reason why this bending is problematic is that cycles assumes light always travels in straight lines. Light does travel only in straight lines, but it can be bent by gravity. Gravity is a distortion of spacetime around objects. The more massive the object, ...


52

Lamp Strength One thing that might be confusing in the beginning when learning lighting is how the Strength value effects different light sources. For example, when you add a new spot lamp, the default Strength is 1.0. However, this is so weak of a Strength that when rendered, it will produce almost no noticeable result, which might make you think the light ...


51

Cycles is a physically based render, and often the best approach is physical recreation. Components: Light source Light cover Light Source: This would simply be an emission shader since it is literally a lightblub or LED. I took the button model, and scaled it down slightly on the X and Y axis. I then drastically scaled it on the z axis, and moved it ...


47

In the object properties, you can turn off Ray Visibility of the 'emission object' for the camera: As of Blender 2.76 the Ray Visibility panel was renamed to Cycles Settings: As of Blender 2.8x, Ray Visibility panel is now part of the new Visibility Panel: You can also run this script to toggle the Camera Ray Visibility for selected objects (updated for 2....


37

First Solution: I have a line-laser and a plane-laser node setup. For the line-laser: For the plane-laser: Second Solution: Now that you have asked and I tried to remember, I got a solution that is easier to understend. You can get the plane-laser when using dot-product instead cross-product. Then higher strength is required. Important Edit ...


36

Emulate light scattering using a volumetric emission shader Using Volumetric scatter produces the most accurate results but required a considerable number of render samples to get satisfactory results. A much more efficient alternative is to fake the light scattering using an Emission volumetric shader. Create an image of the light emission - black where ...


33

An alternative method would be not to use particles, and do the light streaks with curves. It might a bit more tedious to set up, but will not require as much computing power from your machine as particles do. Give the curve a slight bevel and, by animating the Bevel Factor start and end values, you can control how the curve is rendered through the ...


31

I guess military budgets can cover simulations of anything from a quorn to the physically impossible, but when we're doing "black hole propaganda" for our clients in Langley, we always take the easiest and cheapest route lol. Fake black hole can be done with a simple setup and a node material: World set to a black Background shader, Plane with texture for ...


30

From your linked definition of iridescence: Iridescence [is] the property of certain surfaces that appear to change color as the angle of view or the angle of illumination changes. Thus, the following node setup should suffice: If you're not familiar with node groups, this will create a new "node" called Iridescence that takes a base color parameter (...


30

Mesh lights can be useful but they are quite an inefficient way to light your scene - especially with a large number of small lights as in your case. A better solution is to use Point Lamps to light the scene - although those are not visible to the camera which is not the effect you are looking for. The solution is to use a Point Lamp embedded in the center ...


29

Mesh lights can be used with EEVEE but they require an extra step to work: baking indirect light. Here is a scene with a Light-type object (correctly lighting a receiver plane) and two Emission meshes (currently doing nothing) We should add an Irradiance Volume object, and make it encompass the volume that is affected by the light that we want to capture. ...


25

There are three types of Light Probes Reflection Cube Map Reflection Plane Irradiance Volume Reflection Probes The two first are, as the name suggests, to generate reflections for materials. They may seem useless at first because you can enable Screen Space Reflections in EEVEE render panel, however screen space reflections have limitations. They are very ...


24

Cycles uses a physically correct light falloff by default, Blender Internal uses a smoothed falloff with a Distance parameter. Cycles can give a similar falloff by using the Light Falloff node with Smooth parameter. Cycles lamp strength for point, spot and area lamps is specified in Watts, while Blender Internal has no clear physical unit that I know of. ...


24

Simulation Unfortunately since it's not yet possible to vary the IOR inside an object, it can't be simulated completely. However, you can at least use a smoke simulation to distort things based on simulated airflow. Create a fire simulation where the hot air should be. It doesn't have to be very high resolution: Move the domain to an empty layer (e.g. ...


24

Start with a plane that has the proportions of your lamp, enter edit mode and do loop cuts CtrlR so you end up with as many vertices as you need lights. Set the duplication to Verts. Add a spot lamp on the same place as your plane. Select your lamp, then shift-select your plane and press CtrlP and select Parent to Vertex You have now an array of lights! ...


24

UPDATE: As of Version 2.79, there is an option to make an object become a shadow catcher in Cycles. From the release notes This option will make object to only receive shadows in a way that it could be alpha-overed onto another image. The workflow is following: Enable Film: Transparent. Then (Quote from the develpoer's notes) Create an object ...


23

True iridescence is difficult to achieve using Cycles. However, there are ways you can fake the effects of iridescence by shifting the color slightly based on the object normals. This has the advantage of being highly customizable for your particular purpose and much faster than true iridescence would be. Update: I was able to find an implementation of this ...


23

Here's a scene before the curtain. The only light is an emission plane outside and over the window. (clik on the images to enlarge) If we add a translucent curtain we get a lot less light illuminating the room. Adding transparency will allow more light into the room, but will make the curtain "see-trough". Controlling the transparency so that is not ...


22

Matt's answer covers the theory of it, but to provide a visual comparison: Area lamp, 100 samples, 11.08 seconds. MIS (Multiple Importance Sample) on Plane, 100 samples, 12.10 seconds. MIS on So the plane is slightly slower, but it has slightly less noise as well. But now lets try with three lamps instead of only one: Area lamps, 100 samples, 11.31 ...


22

A few things you might try: The color of your background will make significant difference when trying to see the internal reflections. I recommend making the background color the same color as the photo. With a light background like you have now, any light reflecting inside the bulb will be greatly diminished in terms of visibility. Here's an example: The ...


22

I would do this in Cycles using volumetric lighting. Here's the basic setup: just one light on a landscape. Then add a cube around the scene with some volume scatter and volume absorption as materials. for the background you can use a color ramp like this:


19

I don't believe Cycles simulates light as waves. But Dispersion (Diffraction) effects are on the way, and can already be 'faked' in many ways. If you are interested in optics experiment with cycles, take a look at the pinhole camera and shaped bokeh.


19

You can setup the emission material in cylcles like this: Note: @gandalf3 mentioned that disabling visibility is slightly more efficient performance wise than this node setup.


19

cegaton's answer nicely covers the practical impacts of the size setting (i.e. the shadows), but what you are actually setting is the apparent size of the sun lamp. In other words, the size controls radius of the sun as seen by the camera (or any other light ray), regardless of distance. To see this in action, create a perfectly reflective plane and point a ...


19

The use of the Cross Product in that example doesn't make much sense - in fact, I don't seem to be able to get that setup to work. The Value output of the Cross Product gives the average of the individual (X,Y,Z) elements of the vector. This could be argued to make sense if the X, Y, Z all have the same sign (ie, all positive or all negative) but as soon as ...


18

That is a dithering problem. Which is not really a problem at all, but rather what physically must happen. That occurs any time there is a small change in color spread over a large area. One of the ways to get rid of the banding is to make a stronger contrast, such as a pure black background. The best way to deal with it. Is under the Render tab in the ...


18

There is already a great technical answer on how you should use a real light instead of a mesh to light the scene. So I will go into the artistic side a bit more: When you see a strong lightsource, what you are actually seeing is: How the nearby surfaces are lit by it. -This can be accomplished by just cranking up the energy value of the lamp. The light is ...


17

Yes. There is a node called Light Falloff you can plug in to the Emission shader strength. It has three outputs: quadratic or Linear or Constant You my even do some math with the ray length and plug the result in the Light Falloff node strength and use the Constant output. The example is only a demonstration nothing useful.


17

To properly answer your question, I'll lean on the photographic term of F-Stop to define what this range is. What we know: An F-Stop is a halving and doubling of light, relative to the exposure referenced. A scene referred system has scene linear levels of light ranging from zero to infinity. Therefore, to get from the question of dynamic range in stops ...


17

Just create your sphere and over it draw the shape of your cuts using a Bezier Curve object. Adjust its shape as necessary, then use knife project to cut the shape. In object mode select your curve, then without deselecting, select your sphere, by this specific order. Enter edit mode on the sphere and with all faces selected use Knife Project with the ...


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