CCG V3-1 Conversion:Part 9 Visual Effects

From NWN1 Custom Content Guide

Visual Effects

So you want to create your own visual effects? I talked about innovative ways to get NWN to do things it was never designed to do. Visual effects can be used to great success in this area. They have already been used to give creatures wings, to provide a sort of horse-riding feature, and other ideas. So let’s talk about how we create visual effects.

Let me start by describing what a visual effect is. It is, like many other things in the game, a 3D model. The interesting part is that it can be any type of 3D model. Many visual effects are emitters – representing a particle system in NWN. Emitters can be used to produce clouds, smoke, fire, lighting and other special effects. Visual effects models can also be normally rendered 3D models. This is what makes them so versatile.

You invoke a visual effect in the game in different ways.

• You can place a visual effect directly in your module (used to create a dust plume, for example).
• Some are tied to spells (remember the audio and visual effects we discussed in spells.2da?)
• You can also call up visual effects through scripting, tying them to creatures or objects.

There are two main types of effects to keep in mind:

• Duration Effects – these last for a specified length of time (you specify the duration).
• Fire and Forget Effects – these are fired off, they run through their animation, and they go away automatically (duration is specified in the model file).

So we want to create a new effect. It is going to be a waving seaweedy thing similar to the wavy pseudopod namesake of Evard’s Black Tentacles. There are really two things we need:

1. a visual effect model file
2. an updated visualeffects.2da file to tell the game about the new effect

Where do we start? With something similar to what we already want, of course!

Part 1: The Model File

There are, of course, naming standards for visual effects. These aren’t strict naming standards but some effects look like this:

Duration Effects

• VFX_DUR_* (Duration)
• VFX_BEAM_* (Beam)

Fire and Forget Effects

• VFX_COM_* (Combat)
• VFX_FNF_* (Fire and Forget)
• VFX_IMP_* (Impact)

There are other naming standards for special effects tied to spells. Browse through the special effects reference guide at the end of this tutorial for details on those.

Like most other models, the name of a VFX model should not have more than 16 characters. You can find the Bioware VFX models in models01.bif. Open up NWN Explorer and export the model for Evard’s Black Tentacles (VPS_TENTACLE.mdl). Now open the model in gmax.

Note that VFX models have 3 – and only 3 – animations:

• impact (plays at start of effect)
• duration (looping)
• cessation (plays at end)

They can have any of the components or features of a regular model (multiple parts, etc.) When you create the Aurabase object, set the classification on the edit rollout to “Effect”.

Part 2: Emitters

In the case of our seaweedy thing, our model has a series of emitters. Emitters can now be used directly in Gmax – Joco’s updates to Wayland’s scripts now import and export emitters.

However, there is a workaround for this and it is important to understand emitters because so many visual effects use them. The key observation to make is that emitters are just custom nodes. They are nodes in 3ds Max that have custom-defined attributes tied to them – nothing more, nothing less. The reason you cannot use them in Gmax is simply that Wayland’s scripts were not written to import or export them. The 3ds max scripts can read and write emitter files. However, because emitters are just custom nodes, you cannot actually view the effect in 3DS Max. All you can do is change the parameters.

So let’s open up the file in 3ds max. It looks like this:

Image:Ccg fig 44b.jpeg

If you select one of the arrows you will see that it is an emitter. The edit rollout looks like this:

Image:Ccg fig 45.jpeg

If you wanted to add a new emitter in 3DS Max you would go to Helpers, change the dropdown to MDL Suite and select Emitter. On the edit rollout you can change the detailed characteristics of the emitter. These are the characteristics that you can modify:

You can animate some of these properties so that they change during the course of the animation playing (e.g., birthrate). All the value spinners including the color values in the particle menu roll down can be animated. However, the Loop, Tinted, Bounce and Wind check boxs cannot be animated.You will have to play around with others because there may be more which can be adjusted through animation.

So what is the magic workaround I promised for Gmax users? It is this:

1. Open your model in Gmax.
2. Insert a simple node where you want the emitter to be (in the Create tab, select the Helpers button and create a dummy node). Give it a unique name.
3. Make sure you have an Aurabase object. Link the dummy node to it or to an object that is linked to the Aurabase (otherwise it will not export in the next step).
4. Save your model.
5. Select the Aurabase object and export the model.
6. Now open the resulting model file. Look for a line like this:

node dummy <whatever you called your dummy node>
  parent vps_tentacle
  position 0 0 -0.065378
  orientation 0 1 0 -3.14159
  wirecolor 0.425781 0.425781 0.425781
endnode

1. Replace the first line with:

node emitter <whatever you called your dummy node>

1. Insert the following text right before the endnode line:

    colorStart 0 0 0
    colorEnd 0 0 0
    alphaStart 1
    alphaEnd 1
    sizeStart 0.1
    sizeEnd 0.01
    sizeStart_y 0
    sizeEnd_y 0
    frameStart 0
    frameEnd 0
    birthrate 0
    spawnType 0
    lifeExp 1
    mass 0.1
    spread 0
    particleRot 0
    velocity 3
    randvel 0
    fps 0
    random 0
    inherit 0
    inherit_local 1
    inherit_part 0
    inheritvel 0
    xsize 0
    ysize 0
    bounce 0
    bounce_co 0
    loop 0
    update Fountain
    render Linked
    Blend Normal
    update_sel 1
    render_sel 2
    blend_sel 1
    deadspace 0
    opacity 0.5
    blurlength 10
    lightningDelay 0
    lightningRadius 0
    lightningScale 0
    blastRadius 0
    blastLength 0
    twosidedtex 0
    p2p 1
    p2p_sel 2
    p2p_type Gravity
    p2p_bezier2 0
    p2p_bezier3 0
    combinetime 0
    drag 0.8
    grav 3
    threshold 0
    texture fxpa_vine2
    xgrid 1
    ygrid 1
    affectedByWind 0
    m_isTinted 0
    renderorder 0
    Splat 0

1. Use the descriptions above and this template to set your own emitter values.
2. Save and close your model.
3. Keep your fingers crossed that you did it right.

For my example I’m going to turn the emitter upside down and then change the texture to be more like seaweed than a black tentacle. I’m going to use this base and attach it to the upper body of a dryad to make a Kelpie. More on that in the next version of this tutorial.

Part 3: The Visual Effects Resource File

Now that we have created an emitter, we need to get NWN to recognize it. Like other custom content we do that with a resource file (.2da). VisualEffects.2da describes which visual effects are available. This is a breakdown of all the column headings for visualeffects.2da.

F = Fire and forget
D = Duration

0 = False
1 = True

****

Now open up nwscript.nss. This is where the predefined constants are. Add a new constant for your new visual effect by finding the list of effects and add your entry. For example, it typically looks like this:

int VFX_DUR_DARKNESS = 1;

Just list the name and your entry number from visualeffects.2da.

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