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sompson
11-17-2009, 09:07 AM
Hi,

I have a cloth object and a collision object. I calculated the movement of the cloth and everything looked good. But as soon as I hit F9 to render a frame, all the calculated information is lost meaning that my cloth obj just stays in the air without any movement. As if I had never calculated the cloth movement.

Any ideas?

Sekhar
11-17-2009, 09:27 AM
Set the subdivision order to last. If you want it first, make sure the display subpatch level is same as the render subpatch level.

sompson
11-17-2009, 10:55 AM
im also getting very frequent crashes when I use clothfx...
what may cause them?

SplineGod
11-17-2009, 02:17 PM
Save out the motion after running the simulation.

Surrealist.
11-18-2009, 05:03 PM
im also getting very frequent crashes when I use clothfx...
what may cause them?

There are some things that can cause crashes. It is buggy. The most common thing is just giving it too much to calculate. Some of the settings can bring the computer to a crawl if you have a lot of polygons. You have to experiment with each setting one thing at a time to see what it does - if anything. This is the only way to find out what things will do this.

The best way to do cloth is to simulate the mesh when it is in the quad stage.

There are two ways to do this. One is to use a non-subpatched object, the other is a subpatched object that has Last as the Sundivision Order setting.

By setting it to Last, you are asking LW to subdivide the object after the motion of the quads are taken into account. So the cloth is simulated on the quads and then you subdivide that mesh further down the chain. In other packages this is called a Stack. In some other packages you can set the order that the modifiers are applied. In this cas you have a cloth modifier and a subdivision modifier.

In the scenario where you have an object that it not subpatched, these settings don't matter. But you will get render artifacts. So the best set up is to have it as a subpatch object and set the display level to 0. LightWave will calculate the display level (if it is set to First). In this case 0. So ii will calculate the quads. And it won't be slowed down and burdened by the display level. Setting it to Last would be the same as a display level of 0.

By setting it to Last, once the calculation is finished, you can either save the mdd file separately with the MDD Scan and MDD Plug plugins found in the Displacement Tab or use the file tab of the Cloth Modifier.

Either way you can now play back the cloth simulation and adjust the Dubdivision Level to your liking without loosing the simulation data.

Note that you can play back the simulation and change the levels for playback without loosing the data assuming you have it set to Last. The difference here is that if you crash, you loose everything.

So the ideal set up then is to just keep the display level always at 0, set it to Last and then set the render level to whatever you like. You can change this to whatever you want and you never loose the calculation.

You can then expiriment with different Subpatch levles until all looks smooth.

Also assumed is that you will be using a cloth object that is subdivided enough in quads to get the effect you want. This is a better method than trying to run cloth sims on the tris you get with subdivisions.

sompson
11-18-2009, 11:08 PM
Thank You for your answer! It helped me alot:thumbsup: