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Author Topic: Dodgy materials on some objects  (Read 592 times)

iCreateLtd

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Dodgy materials on some objects
« on: May 06, 2016, 08:02:49 PM »
Hi,

I've just set up a new library and have done a test render.  Two cars have strange things happening to them. I'm not sure if there are other dodgy cars.



The bottom one has transparent tyres.  You can see they're there but you can see through them. 

The top arrow one should be a yellow car.  Its tyres also seem to be white.

These cars render fine in the master scene I've made for them for FP so something is happening when FP brings them in.

Any help would be great.

Thanks

iToo

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Re: Dodgy materials on some objects
« Reply #1 on: May 07, 2016, 09:23:11 AM »
Please, would you convert this object with Forest Tools and check if problem remains ?

Forest creates a multi-sub with all materials defined in the Geometry List, so this may be caused by the modified material IDs.
But we should see the scene to know what is the problem exactly. If you send us a simplificated scene, we can check it.

Thanks,
Carlos Quintero
iToo Software

iCreateLtd

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Re: Dodgy materials on some objects
« Reply #2 on: May 07, 2016, 02:09:30 PM »
Hi.

I've sent the scene to the address on the link you gave.  I've added this topic address to the message on weTransfer.

Thanks

iToo

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Re: Dodgy materials on some objects
« Reply #3 on: May 09, 2016, 09:49:46 AM »
Thanks, we have received your scene but there are several maps missing. If possible please send them as well.

Anyway, in our first test i noticed several errors in the V-Ray log.
I suggest you fix them, because objects or materials which render fine as standard objects, may fail when rendered as instances. We have seen this problem other times in V-Ray.
Carlos Quintero
iToo Software

iCreateLtd

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Re: Dodgy materials on some objects
« Reply #4 on: May 09, 2016, 10:44:22 AM »
Hi.  Thanks for taking a look.  I'll  try and fix some of these issues but annoyingly I can't do anything about the missing textures called 24REK etc.  I can't find them anywhere.  Are the missing texture important?

Would it be better to delete the materials using these textures rather than have missing textures being used?  Actually, maybe I should just create small, insignificant textures with these names.  That'd hopefully prevent issues down the line.
« Last Edit: May 09, 2016, 12:06:18 PM by iCreateLtd »

iToo

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Re: Dodgy materials on some objects
« Reply #5 on: May 09, 2016, 12:13:40 PM »
Ok, i didn't know if these maps were important or not. They are used in the cars, but probably assigned to unused IDs.

Ignoring these materials and checking the scene again, i could find the problem: As said on my initial post, Forest creates a multi-sub with all material used in the Geometry List.
In this case, the number of unique materials exceeds 999 which is the limit for a multi-sub. Therefore, some IDs in the final geometry are wrong.

There are several workarounds (as create several FP objects with less materials), but the easiest method without changing anything in the scene, may be to use Forest Tools just before rendering. If needed, you can revert to the original FP distribution with a couple of clicks.

I hope that helps.
Carlos Quintero
iToo Software

iCreateLtd

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Re: Dodgy materials on some objects
« Reply #6 on: May 09, 2016, 12:41:26 PM »
Thanks for the informative reply.

I haven't used Forest Tools yet so will look into it later.

The car library I have has 50 cars in it.

Quote
There are several workarounds (as create several FP objects with less materials)

By this, do you mean that I, for example, create a forest object and select quarter (or whatever) of the cars, then create another forest object and select another quarter and so on?

That way, there will be 4 multi-sub materials or at least less than 999 materials on each multi-sub?

iToo

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Re: Dodgy materials on some objects
« Reply #7 on: May 09, 2016, 01:17:48 PM »
By this, do you mean that I, for example, create a forest object and select quarter (or whatever) of the cars, then create another forest object and select another quarter and so on?

That's it.

Quote
That way, there will be 4 multi-sub materials or at least less than 999 materials on each multi-sub?

The idea is that number total of (unique) materials by FP object is less than 999. Forest, as any other Max object, only can have assigned an unique multi-sub material.
Carlos Quintero
iToo Software