Join Brian Bradley for an in-depth discussion in this video Caustic effect setup, part of V-Ray 3.0 for 3ds Max Essential Training.
- Caustic lighting effects can be seen pretty much everywhere in the world around us. In fact oftentimes, they become such a familiar and expected sight we don't always notice that they are there. For instance, not many of us take the time to stand and watch as focused light patterns create quite dazzling light display as we fill a bathtub for instance and yet caustics are there because they're just a part of the natural way in which light behaves. Of course this naturally occurring real world lighting effect doesn't show up by default inside a CG lighting setup.
Typically speaking, we have to deliberately enable caustics and then work with a distinct set of controls in order to tweak and tune the effect, which of course is exactly what we're going to be doing in this exercise. What we have in our test scene here essentially are the building blocks from which we can create a caustic lighting effect. We have a strong directional light source in the form of a V-Ray sun. We have a few suitable pieces of geometry although we will work here with this foreground butterfly ornament, to which we have also applied an all important refractive material, namely glass.
As things stand then, we would probably expect to see caustics generated in our render once we enable them in the scene of course. Well, we will see if that is the case in just a little while be before we go ahead and try that, I just want to tweak our scene setup a little so as to speed up the test renders that we're going to need to take here. Firstly, from the layout manager, let's go ahead and select only the scene elements that are absolutely essential to the creation of our effect, these being the foreground butterfly and plinth geometries as well as our daylight system lighting elements.
Once we have those selected, we can use the button at the bottom of the 3ds Max Interface to enter isolate mode. We can now perform quick and easy test renders using as we say, only the elements that are really needed. In fact, let's finish off our setup here by having the geometry render against an all-black background. Of course, the problem we will run into if I just open up the Environment and Effects dialogue using the A key, turn off the V-Ray sky environment map, and then take a render, is that in setting our background to black, we have also lost the V-Ray sky's contribution to both lighting and reflections in the scene, which of course in this instance, is not really what we are wanting.
Let's use a little bit of V-Ray functionality then to get around this problem by first of all opening up the Render Setup dialogue and from inside the environment roll out, in the V-Ray tab, enabling the GI Environment option. From the Environment and Effects dialogue, we want to right click on and copy our V-Ray sky map. We can then instance paste it into the GI Environment Map slot. If we were to take a render at this point, we would see that we have now reset our scene lighting.
All we need then are our reflections. For this, we need to enable the Reflection Refraction Environment and then instance paste a copy of the V-Ray sky into that map slot also although if we go ahead and take a render now, we will see that things look a little odd. This is because the refraction parameter in our glass material is still reading the ultra bright V-Ray sky map as a background rather than the solid black color we see in the render. If we go ahead though and enable this very specific Refraction Environment option, leave the color set at black, and then render again, we can see that things instantly look much more believable and we are of course getting the really quick render times that we wanted here.
Just to be clear then, the background color we see in our render is being provided by 3ds Max's native background color functionality as found in the Environment and Effects dialogue whilst the lighting and reflections and refractions in the scene are all being provided by these V-Ray specific environment controls. Finally, as we clearly have no caustic effect present in the render at this moment in time, let's go ahead and from the Caustics rollout in the Render Setup dialogues GI tab, enable that option in the scene, meaning we should theoretically be good to go with our caustic effect.
If I go ahead and hit the Render button however, we do very quickly see that enabling caustics and actually getting them to appear in our render can oftentimes be two very different things. Indeed, there are a number of very specific steps that we still need to take before we can successfully render caustics in our V-Ray scene. These, we will take care of in our next exercise.
- Using the new UI elements, Quick Settings, and revamped Frame Buffer
- Understanding color mapping modes
- Adding V-Ray light types
- Working with the V-Ray Sun and Sky systems and dome light
- Using irradiance mapping and light cache
- Working with diffuse color maps
- Making reflective materials
- Creating a translucency effect
- Using the new SSS and skin shaders
- Ensuring quality with image sampling
- Working with the adaptive subdivision engine
- Controlling the physical camera
- Working with FX tools such as VRayFur and VRayMetaball
- Stereoscopic 3D rendering
- Using Render Mask
Skill Level Intermediate
Q: This course was updated on 02/02/2016. What changed?
A: We added tutorials on the new 3ds Max camera tool, which replaces the defunct V-Ray Physical Camera. The author also includes a method for creating a V-Ray camera via scripting.
Q: This course was updated on 04/19/2018. What changed?
A: New videos were added that cover V-Ray 3.1 to 3.3 updates.