Tuesday, February 6, 2007

A simple Heliodon setup

Let's assume you have a building site and now you want to do some outside rendering. To give it an optimistic, comfortable mood we want a lot of sunlight in our scene. To do so we set the time to July or August. The time of the day will adjust the angle of our light coming into the scene. If you want longer shadows set something in the morning or evening, for shorter shadows we need something at noon. Artlantis will now calculate the sun direction automatically, but you can change it manually in 2D view (as in the screenshot). I suggest setting the direction of the Heliodon to go with the camera view and then to slide a little.

The first input box with the sun/cloud icon adjusts the direct light. The ( ) radiocity box underneath sets the diffuse or indirect light. Theoretically there is no need to check the radiocity box, but I recommend using it in order to soften you image and to give it a warmer appeal. To achieve a mid-summer coloring set the radiocity color to a very bright yellow, for example RGB (255, 255, 240).

Texture layer tricks

As you can see in the picture the floor is covered with white and black tiles, but only the black ones reflect their environment. The technique behind this was first explained in detail by Ivan in this thread. In this case the material for the floor has two layers. The lower one has both black and white tiles and the reflection slider far to the right.

The top layer is basically the same texture with no reflection. To make only the black reflecting tiles of the bottom layer visible we cut out the white tiles from the top layer. To do this we replace the white tiles with red in an image editing program and then check red to be the invisible color. You could also use an alpha channel to make the white tiles invisible.

Additionally we can set a bump or roughness, but it's not really needed here. You can also play around with transparency and color mix.

Monday, February 5, 2007

Water and you

The most ordinary way to create a water surface is the normal shader. Since water has no color you give it the color of your environment and you give it some reflection. A little more complex - and longer to render of course - is the Freznel Water shader, where you can sat a wavy reflection. The problem is that your water surface still is absolutely flat, there are no ripples and waves.

As suggested by Gerrit in this thread there is a more advanced way to produce convincing water. To do that we use a greyscale picture for the bump map, two of those can be found in the link. Apply the bump image in the texture mapping dialog and make it entirely transparent, bump it and add reflection.

Along with the bump we need reflection, so drag the slider to the right. Remember that we need both, reflection and bump.

As you can see in the screenshot I am using the normal shader for the water material. You could even add the Freznel water shader here, but the change is in my opinion hardly visible and not worth the render time.

Sunday, February 4, 2007

My Artlantis wishlist

This is a work in progress .. as soon as I come upon something I will add it here.

Establishing Artlantis as a presentation tool - When it comes to presentation it always was an architect's dream to take a virtual tour through a building or site. There are applications out there that allow free movement - but only at low visual quality. In my opinion Artlantis should offer an export format where all lights, materials and polygons are precalculated, leaving only the rendering as the final step. That is exactly what computer games have done for years. We then need a freely avaible viewer application for our clients that allows free movement with WASD keys and mouse.
What I have in mind would be some revolutionary step and a lot of engineering, but it is something that architects worldwide are hoping for. Abvent could really break new ground here.

Multiple timelines - This is maybe my most missed feature. At the moment Artlantis has only one timeline for a multitude of animation aspects - objects, camera position and target, lights, heliodons etc. Multiple timelines just like in applications as Apple Finat Cut Pro or Adobe Flash would be a nice addition. Multiple timelines don't necessarily take up more space, tabs are the way to go here.

Groupable objects and textures - Unlike light objects you can not put textures and 3D objects into groups. As a result you can not deactivate them individually for each camera.

Work distribution - Today it is quite common to have more than one computer but Artlantis currently does not make use of them. It would be nice to keep configuration work to a minimum. Just start Artlantis on multiple computers and render work is distributed automatically.

Text options - At present Artlantis has no tool for overlay text information. It would be nice to see information on the project name, date, daytime and camera name in the rendering or movie itself. Another aspect is some information on the technical background of the rendering, maybe written into a seperate text file. Working on a project we create dozens of renderings and a few days later it is hard to tell which settings are responsible for which rendering.

Limited fog - We can set fog in Artlantis, but we can only limit it in height. Maybe a special object - a square or a cylinder - is the way to go here. You drag it from the library into your scene and then we have fog only inside of that object. This way we can create fog, smoke and steam.

Advanced VR - QuickTime VR is a nice way to show an object to a client but Studio misses a lot of advanced options. It would be nice if we could define hotspots and connect VR objects for example.
There is another thing with VR. It would be a nice addition if we could bend the Y-achsis of the panorama. At present all VR's are perfectly horizontal, i.e. all cameras have the same height. Now if you have a house built on a slope and make a VR object of it the camera is forced to move through the hills.

Better reflection control - At the moment Artlantis does not allow users to control reflected objects on a surface. Sometimes it would be useful to prevent 2D objects from being reflected in a window or on a water surface. Grouped objects - right-click on a surface - checkbox yes/no - is the way to go here.

Advanced materials and lights - Sometimes it would come handy to have ... 1) light objects that draw shadows but that don't brighten the environment. For example the Neon Light shader does not draw a clear and crisp shadow. A light object that created nothing but shadows would be useful here. ... 2) materials that draw shadows but are invisible themselves. At one instance I wanted to simulate the shadow created by a tree without showing the tree itself. Unfortunately I wasn't able to do so.

Multiple activation frames - It would come handy to define multiple activation frames. That way we had better control which parts of our scene should be revealed.

Same Heliodon for interior and exterior rendering - Currently a heliodon that is perfect for an exterior rendering is to weak to brighten an interior and vice versa. Maybe there are ways to improve that.

Faster rendering - This is of course a permanent challenge. As threads in the Artlantis forum has repeatedly shown, Artlantis is maybe the fastest rendering engine avaible to achieve a fairly good quality. But scenes with a high amount of glass and reflection take days to render. Maybe there is some way to trade quality with shorter render time.

Free movement in 3D mode - At the moment there are ways to navigate in 3D view, but mostly I move the camera in 2D view. W-A-S-D and mouse movement in 3D view would be a welcome addition.

Automatic naming of render files - We all know it's a pain to give dozens of renderings a name manually.

Change all render settings at once - Currently you can define a render quality preset but you have to apply it to each camera manually.

Remove some redundant options - At the moment the are a few options that seem redundant or misplaced. For example one can set the sky illumination for a Heliodon which is labeled as radiocity ranging from 25 to 300%. The 2D window now has it's own radiocity setup ranging from 50 to 200%. Another example is the texture mapping dialog. All materials have a reflection slider and if you assign textures to it they have their own reflection setup. Maybe things can be streamlined here.

Merging TGA's - Artlantis allows users to render the frames of a movie or a VR object to TGA format. We then have to use QuickTime Pro to make a movie out of these, since Artlantis does not offer a tool to merge the files for us. It's even worse with VR objects because QT Pro does not allow VR authoring.

Using Freznel Water for glass

What is glass? It has almost no color, it reflects it's environment and it reflects light. That's why I use a very bright blue as the basic glass color (RGB 245, 255, 255) and a tone similar to the sky color for the reflection. The normal shader is fine with most *exterior* rendering setups.

The problem is that often glass is not equally thick resulting in a wavy reflection. Because of that I recommend using the Freznel Water shader. It takes a little longer to render of course, but unless you have consecutive layers of glass you won't notice on faster machines. Find my settings on the left. The result will look as shown in the screenshot.