Modify the color of a mesh

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Charlie111
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Modify the color of a mesh

Post by Charlie111 »

Hi,

I would like to change the color of my mesh during the game.
What is the most efficient way to do it??
I think I have to play with the material of the entity but I don't know if it's the must.

Thanks

Charlie
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spacegaier
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Re: Modify the color of a mesh

Post by spacegaier »

Yes, the visual appearance of a mesh is defined by its material script. Those can be modified at runtime.

Code: Select all

m_pMat = m_pEntity->getSubEntity(0)->getMaterial();
m_pMat->getTechnique(0)->getPass(0)->setAmbient(1, 0, 0);
m_pMat->getTechnique(0)->getPass(0)->setDiffuse(1, 0, 0, 0);
m_pEntity->setMaterialName(m_pMat->getName());
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Charlie111
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Re: Modify the color of a mesh

Post by Charlie111 »

Ok thanks for your answer.
Is it time consuming??
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spacegaier
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Re: Modify the color of a mesh

Post by spacegaier »

I assume you mean the performance: I never had any problems with it. I even used to make this call once per frame in order to constantly change the alpha value so that my objects fade in and out all the time.
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Charlie111
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Re: Modify the color of a mesh

Post by Charlie111 »

Yeah that's what I meant, sorry for my english :wink:
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wacom
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Re: Modify the color of a mesh

Post by wacom »

Be aware that changing an entity's material changes all entities which share this material.
Charlie111
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Re: Modify the color of a mesh

Post by Charlie111 »

Ok so I have to create a new material each time... but I will quickly have some memory issues... any advice?

I want each entity to be independant from all the others.

Anyway I have a problem... I've changed the color but nothing happen on screen (I checked in debug).
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spacegaier
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Re: Modify the color of a mesh

Post by spacegaier »

Did you stick to the example I posted above, meaning that you also applied the altered material to the Ogre::Entity? Just chaning it in the code without reapplying won't make anything happen visually.

Yes, you will need an own material for each Ogre::Entity if you want them to look different. As the materials are nothing big, I would not bother about the RAM.

You can therefore clone one exisiting materal, if you only have to change small things (of course you can also define new ones everytime).

Code: Select all

Ogre::MaterialPtr* m_pMat = m_pExistingMat->clone("NewMatName");
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Re: Modify the color of a mesh

Post by ekt »

<shameless plug>
this could be your solution :)
<shameless plug>
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