Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: OccultMonk on 2018-05-19, 07:02:38

Title: Performance impact of complex multi/subobject-materials vs direct assignment?
Post by: OccultMonk on 2018-05-19, 07:02:38
I want to have many variations of the same complex model consisting of many objects. These variations can have different colors/paints/metals in different places of the model. I wanted to create a multi-subobject for each material variation. So a multi/subobject for a green car with white plastic and one for a red car with metal and dark plastic (consisting of 30-50 slots).

Is there a performance hit using a multi/subobject material with 50 slots on all objects at once instead of assigning the materials to each object sepertately?
Unfortunately, I do not have time to test this out myself at the moment.

Also, is there maybe a better solution for having many different material combinations/versions? of a vehicle within the same scene. I want to have preset 'versions' that I can easily swap: Green car with plastic, red car with paint... (only far more complex).
Title: Re: Performance impact of complex multi/subobject-materials vs direct assignment?
Post by: OccultMonk on 2018-05-19, 19:33:01
I also posted a more detailed question about complex material assignment here, but it's not really Corona related. More 3dsmax specific:

http://polycount.com/discussion/201255/3dsmax-many-material-variations-on-the-same-complex-model-in-one-scene/p1?new=1 (http://polycount.com/discussion/201255/3dsmax-many-material-variations-on-the-same-complex-model-in-one-scene/p1?new=1)
Title: Re: Performance impact of complex multi/subobject-materials vs direct assignment?
Post by: OccultMonk on 2018-05-23, 08:52:05
Is there no performance impact when using Muli-subobjects materials vs individual material assignment?
Title: Re: Performance impact of complex multi/subobject-materials vs direct assignment?
Post by: PROH on 2018-05-23, 11:27:33
Hi OccultMonk. I'm using multi-subobject material extensively in most of my work, and from my experience (haven't done accurate testing) there's no performance penalty when it comes to rendering.

There is however one thing that produces some extra lag and freezing when using multi-mats: the material editor. The time to load large multimaterials can be quite long, and it seems to be even longer if you're using a dual Xeon setup.
Title: Re: Performance impact of complex multi/subobject-materials vs direct assignment?
Post by: romullus on 2018-05-23, 11:27:36
Never tested, but i doubt that there should be any measurable difference. Multi sub object is only container material, it doesn't mix or blend materials in any way. Personally i'm not a fan of extensive use of multi sub object, as i find that it makes managing materials more confusing.
Title: Re: Performance impact of complex multi/subobject-materials vs direct assignment?
Post by: OccultMonk on 2018-05-24, 05:54:29
Never tested, but i doubt that there should be any measurable difference. Multi sub object is only container material, it doesn't mix or blend materials in any way. Personally i'm not a fan of extensive use of multi sub object, as i find that it makes managing materials more confusing.

Then how would you manage a scene where you want many versions of the same very complex model consisting of 10.000+objects? I want a vehicle to sometimes have plastic parts and sometimes metal parts, different colors... Using different scenes is not a solution because of the filesize... I posted the question here:

http://polycount.com/discussion/comment/2633095#Comment_2633095 (http://polycount.com/discussion/comment/2633095#Comment_2633095)


What would be the best, most durable way to have many versions of assigned materials in one scene, so that I can easily switch between a version of the vehicle with green paint with white plastic and the same model with metal and dark plastic. Making it extra complex is the fact that not all materials will be assigned precisely at the same location/subobjects.

Example: A vehicle (same model) with many colors/material variations, where for example in one version some parts are of a painted material and in another version some parts are plastic or metal. (And then with about 50 materials on thousands of objects) How would you manage that on complex scenes? None of the solutions I found is flexible enough:

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Title: Re: Performance impact of complex multi/subobject-materials vs direct assignment?
Post by: Ondra on 2018-06-12, 17:15:21
Hi,
multi/suboject and individual material assignents are likely translated to the same thing (I am not sure what you mean by the second one, but it might be the case that it even creates multi/subobj material automatically in 3dsmax). There should be absolutely zero performance difference in corona