Bump and Displacement in the Phong Profile
I see that the new Collada 1.5 does not have any bump or displacement elements for the Phong profile. I realize that the Max extensions have this, but why wouldn't the common phong profile accomodate this? Bump and Displacement are very common attibutes on all DCC and 3D graphics platforms. Is this somehtnig I should write up and submit to someone at Collada? If so, how do I go about doing this?
We looked into this and realized that there are so many definitions of Bump, Displacement, Normal map that are specific to implementations that we did not manage to create a common spec.
We found out that most, if not all, game developers are using shaders to create such effects, and have no desire to convert from the DCC tool bump definition to their own material/shader definition.
In fact, the issue you just raised is just the top of the iceberg which is how DCC tool support shaders. COLLADA FX is doing quite a good job at this, and one can use the Max/Maya/Softimage/FXComposer tools to create COLLADA FX files that can create effects such as BUMP, exchange between those apps, and use it in their run-time.
Remi, thanks for the explanation. I'm puzzled however. I thought Collada was going to be an exchange standard which also would work when moving data between DCC systems and not just game systems. There are a lot of people now trying to use Collada to move data between apps like Poser, Vue, C4D, Blender, DAZ Studio etc since these apps now support Collada. Is there anyway to put a formal request in for something simple like adding a few tags such as:
<bumpheight> float </bumpheight>
I realize that this does not cover the entire spectrum of possibilities (e.g. displacement, normal maps, etc) but at least it' a start that would cover perhaps 60% to 70% of the DCC to DCC systems.
Yes, it is possible and welcomed to make such requests.
The best is to open a bug/rfe on the collada bugzilla to make an 'official request', which does not appear to be listed clearly on the collada.org front page. (I'll inquire about this)
You should also contact all the DCC vendors your work with, or want to work with and make the same request to them.
At one point, one of the COLLADA working group member (Khronos member) need to put some time behind this proposal, and make it happen for a next release. So another possibility is to become a Khronos member and to make it happen.