Reactor Hints


couldn’t honestly tell you what to do on that one. most likely the correct answer is to simply reinstall max, looks like something got corrupted. id on’t think ive ever gotten that error before.


yes, i did that of course, no change -


and it does tis for the most basic scene (cube falling in space)?


before you reinstall max - check what rendering method you are running in the havok window, try changing to DirectX, or uncheck “use direct x” if that is what you are running. set pixel format sounds more like a directx method. I couldn’t be sure.

I have had this problem when i’ve run the preview via the Macroscript on a floating toolbar. I’ve never had it pop up when i run from the utility panel. there’s a fix of sorts:shrug:


hmm, thats a good point. have you update directx or your video drivers lately? that could be what is messing you up, i would imagine the preview uses your vid card and so if you did something funny with the drivers…


indeed i just changed over to directX and avoided to use the floating toolbar. after adjusting a few details for directX it seems to work for now. seems time to change the ati card for nvidia.
thanks a lot for your help, guys, cgt worked again!!


Largo39 thanx for the tip! Very helpful for quick references.

I’ve a basic problem with reactor rope that maybe you can address.
I have an object (Mass 1.0kg) attached to a rope (Mass 10.0kg) using reactor attachtoRB modifier on the end vertex of the rope. The other end is fixed. Problem is as the object falls the rope stretches along to infinity in the preview window. It doesn’t snap back to its original shape. I tried the method you proposed:

  1. rope object streching a lot? you can make it so that it keeps its shape (under rope modifier hit keep shape). if an object is attached to it the rope may still strech, so increase the mass of the rope from 1 and it should deal with the stretching.

Yet it doesn’t solve it at all. I’ve tried both constraint and spring parameters for the rope.
What’s gone wrong and how do i solve it? I’m using Max 5.1 reactor 1.5.


oh, just realized something which may be a factor… im using max 6. hmm, need to find out what the standard version of reactor is for 6.

well, anyways, the basic things to try are to increase your substeps and DECREASE your collision tolerance to around .3, how to do both of which i think can be found in this thing… somewhere lol. you might still try having the object just a bit farther from the rope, that may affect things.

want to post or pm me the file? ill take a look at it.
other than that… it takes tweaking, might turn on “avoid self-intersections” or, simply change the position of the object and rope, maybe something else in the simulation is causing something wrong.


It’s a simple set-up which is why it not working confuses me.
You can get the file here:

The filename is reactor_rope_bolo.max. Done in Max 5.1.
Thanx for your help!


Good thread! Thanks. STICKY!?:bounce:


ACK! i feel stupid!! im sry, just hit the “constraint” button (instead of spring) and it will keep its shape. keep shape is for something else. wow, i have to fix that, sry!

leonec: i hope its proven useful, its not up to me to make it sticky or not.

edit: has been fixed.


thanks for all the hints!! iam not working on clothing right now…but you will hear from me soon again :-p.


:thumbsup: Hi there guys, ive got a character skiing on the back of a boat and ive got some really cool looking waves from reactor but for some reason the waves are not going above the ground plane all the action is happening below the level of the plane.
Is this a problem with reactor or am i not using something properly.
If anyone has an idea, id like to try it out.


hmm? i don’t understand your question. below WHAT plane, the water plane of reactor or some plane you created?


Sorry bout the lack of info Largo but i can usually work things out if i work with it long enough but this has me wandering. Im not sure if reactor water is capable of doing what i want it to do or if im doing it wrong or do i cheat it some how. ( If u need to know i use reactor a fair bit and ive read a lot of tuts but none have really covered this)
what i have attached is a pic of a blue plane(linked to the water modifier) which is acting as water, there is a board going through the water and that is making the wake in the middle of the pic. My problem is that as you can see the outer walls of the wake is the same hieght as the plane which is not a real wake the outer wake should be higher than the plane. im trying the wave height values but it only effects the inner motions of the wake. Would you know if this is possible cos other wise ill have to look else were. hope this makes sense.
Any help will be appreciated.:thumbsup:


anyone know how to display vertex colors in the reactor viewport? i saw a demo using reactor cloth, and the woman had a few vertex’s along an edge displayed in red



ARGH, im sry guys, i totally missed these questions.

zad: try increasing the max and min ripples, this will help make the waves more like… waves… reactor water CAN ripple, but if your water is large the default ripples may be too small. if that doesn’t work… u could try “dropping” something into the water just before the boat enters, or have the boat fall a little bit to start the waves going, but it shouldn’t need that. hmm, ill do a test.

jason: not sure what that is, could just be a vol select or the person selecting the verts of the mesh (after either making a mesher or it or a snapshot) and then showing how you can tweak the results.


today im gonna talk about two constraints (what i just did tests on) and their absolute COOLNESS. remember… CONSTRAINTS ONLY APPLY TO RIGID BODIES. so the spring object (not a constraint that needs a solver but still is RB only) and point to point that i will be talking about ONLY apply to something that cannot deform (guess u would just do that manually). oh well.


this one is pretty simple, you just click it, and set the parent and child, i noticed the damping was VERY high and had to reduce it from like 1 to .5. dampening basically tells you much much the spring calms down, and stiffness applies to the stiffness of the spring, so the higher the stiffness the more it takes to compress but you get more power. you can also just have the constraint apply to one body, making it more “bouncy”.

the align spaces too essentially just defines which RB becomes the spring. selecting “each body” will draw a line between the two bodies and that space between them BECOMES the spring.


[/b]1. another way to make a spring is to use a soft body with a fair amoutn of stiffness and then whenever something hits it will bounce off.

  1. or… you can simulate the spring constraint, key the results, and then delete the constraint, and set the masses of the objects to 0. then create your spring object, make it a soft body, stick it in the middle and constrain the verticies to both objects. the body should have 0 mass and little to no dampening. then set max to start at the frame after the movememtn to collect velocity info and voilia! it will compress and lengthen to the keyed motions of the rigid bodies. cool ehh?

Point to point constraint:

can’t tell you how much i love this sucker, its basically link but with so many cool features. anyways, first thing you need is a constraint solver, which includes the constraint and you also must define which RB collection your dealing with.

making the constraint itself is simple, you create it and then define child and parent. the alignments are also the same stuff as spring, and each body (which only opens up when you select it as stiff spring, ill get to that soon) is the line in between.

so basically this links them togethere, where one goes the other goes. although i notice you can’t set a key when the spring dies (and i noticed the strength is not keyable), u could do that with fracture as well.

Cool Features

breakability: you can break this based on velocity (angular is rotational, linear is horizontal). so, for example, if you had a block constrained to a spinning plate as the plate spins faster eventually the block shoots away.

spring: yay! this thing can also be a very constrained spring (i notice that with the spring object if it goes too far off it falls away), and then when something hits it or it moves too fast it flys off! very cool.


well, ok, i tested it and your right, it doesn’t break the plane. but then i looked at some wake boarding pictures and noticed that they don’t break the plane either int he initial few seconds , they do LATER but so does reactor.

so wahts the bit thats “over” the plane? thats the SPRAY and thats the realm of particles and pflow heres what i would try (very general instructions, don’t know if it would work completly):

  1. make some small boxes and stick them in the boat where you want them.
  2. make a pflow object and an event called “spray”, set the first box as emitter
  3. add gravity force, add it to the event
  4. make your water plane into a deflector, add a collision test to the event
  5. tweak the particles (ur gonna want lots) so they arc correctly and then hit the plane (and prolly delete at the point, so you would add a delete to a new event and link the collission to the delete)
  6. make your material! heh


Thank you so much for that info largo, U ROCK. Ill try it over the weekend.
I also c that you have “Deconstructing the Elements…” By Pete Draper at the bottom ylour pages. I am just about to order it, it looks great, would you know what its like.
Keep up the excellent work Largo:thumbsup: