Sorry for the delay, I finally got around to being able to write this up. I can only hope your body is ready for this wall of text. So, things that have been worked on since the last write up are:
- Obsidium Spikes
- Brazier Fire and particle fx
Before I started on the spikes I had a few things I wanted to achieve with their construction. I wanted them to all share the same UV space for diffuse, normal, spec, etc but to have different UV shells for the lighting channel. I wanted the texture to animate a cloud texture along the length of the spikes as well.
Modeling the spikes was easy. I made a four sided cylinder in max, tapered it to the top point and then did all of my UV unwrapping, texturing, and ZBrush sculpting with it being straight as an arrow. Once I was done with the basic construction I applied separate bend and twist modifiers to chunks of the spikes to achieve some interesting shapes. This worked out great because I had minimal UV stretching and I was able to re-use the texture layout on all of the spikes.
The material, while mimicking the layout of previous layouts, had to be created specifically for this item. This was mainly due to the panner being applied. Iím sure I could have just created a switch that turned off the clouds, but there were some minor tweaks I wanted to have more control over as well.
There isnít much to say about the brazier itself. The construction followed the same workflow as the altar and even uses the same material instance. The only difference is that the coals are a separate material channel with a newly created material placed on them. I wanted the emissive channel to look as though heat was moving across the surface. This is the node chain I created to achieve the effect.
The Cosine causes the light to pulse while the constant clamp stops the color from going below a value of one. This was done so that the emissive would never go black. The cloud mask was set to a panner and then multiplied over the constant clamps output to make the brightness appear as though it were moving across the surface and not pulsing in the same location every time. The panner was set to a speed of 5,5. This was the only part of the material that really sets it apart. The rest is more or less business as usual.
Brazier Particle Effects Materials
I knew that I needed to make a particle effect for the fire, smoke and embers. First of all, I knew that I needed a tiling flame texture.
While UDK has a tiling flame, I wanted the experience of creating one from scratch and also, I needed it to be purple to keep with the in game screenshots. http://www.cgtextures.com/
has some great shots of flames and while they are not tiling, I was able to create one in photoshop. I also made sure to create an alpha channel for transparency as well.
So, on we move to the material node creation-
First, the ďBlend ModeĒ is set to translucent and the ďLighting ModelĒ is set to unlit. The emissive channel is powered by two copies of the flame texture that are tiled at different sizes and panning in different directions and speeds. When added together this cause the fire to look really chaotic as it dances. Of course, in your case you may find better results with different values. Try it out to see what you get! Then I multiply by a scalar parameter which is to control the emissive intensity. Finally I multiply by a vertex color. This is important! If I want to change a color value over time in Cascade, it is controlled by a vertex color.
The opacity is pretty simple. Youíll see a TexCoord is plugged into a component mask (G) which is a really simple way to create a gradient in UDK. When multiplied into the moving alpha channels this ensure that the ďtopĒ of the flame always fades out. This is then multiplied by the vertex colorís alpha for the same reason I explained before.
Youíll also notice I have an unconnected node in a red box. I decided to use a mesh for my flames, however, if you decide to use a billboard effect you will need this node. If you search UDK for ďMaskĒ you will find a circular image with a slight falloff. If I set the textureCoord to 1, .5 then I get the stretched out half circle which works great for a final multiply mask. If I multiply that node at the end of my chain I will get the following effect on a billboard.
The ember effect is simply a material that uses the circular mask I just mentioned multiplied by a vector parameter for color and a scalar parameter for emissive intensity. These are then multiplied by a vertex color so I can have animated control over the emissive power and opacity in cascade. Really simple.
Iíll be honest, Iím not totally happy with the smoke as of yet and I may come back to it later but as for now, here it is.
As you can see, itís really simple. Most my editing for this to look good will be done in cascade soÖON TO CASCADE!
Brazier Particle Effects Creation (Cascade)
Iím still learning about Cascade as it is so my explanations may be lacking. For some great tutorials, Polycounts very own Lee3Dee has a site called www.explosions-rainbows.com
which has some pretty neat stuff on it. You can also find his Youtube channel at http://www.youtube.com/user/gizm0san
. He doesnít have anything to do with this project, but he makes some damn fine tutorials. Also, 3Dmotive
has bought out ImbueFX and should hopefully be releasing a cascade video set in the future (I hopeÖ)
The flames are pretty basic as they are mainly controlled by the texture itself. The big change is that theyíre referencing a mesh instead of being place on a billboard effect. They are the only particle in this chain that does that. They have a slight randomness in size that allows them to change when they spawn and their lifetime is set between 5 and 8. There really isnít much to these.
I had some fun making these. The embers needed to really appear as random as I could make them. Their lifetimes are set between 1 and 10 and the size is between 5 and 25. The main point I made was to create a solid range that they could move around in without them flying clear out of the path. The color over life node also makes it where they are much brighter when they spawn and they found out before they die, so that they donít disappear suddenly. The orbit is what causes them to spin wildly.
The smoke is by far what took the longest as well as the most amount of tweaking. Most of these nodes are self explanatory for their purpose. It was really just trial and error for the most part. I edited these nodes so that the smoke rotated as it moved upwards, the size of the clouds doubled over time, and the clouds moved upwards at slightly different speeds to break up uniformity.
Youíll also notice that even though my smoke texture was grey, it transitions from a purple to a very dark grey over its life. This is all controlled by adding that vertex color node within our material. Over the lifetime of the smoke I am multiplying a color over our texture. As it nears the end of its life, I am also animating the alpha of the vertex to fade the clouds out so they donít disappear suddenly.
If you have any questions please feel free to ask. Iím off to work on this more and get my ass kicked playing Dark Souls.