displacement on models not rendering when raytraced

[gregsandor]

Anyone else having trouble with displacement on models not rendering correctly when Raytrace Objects is on?

[old_blaggard]

The raytracer simply doesn't support displacement on models. It only does bump mapping.

[gregsandor]

Are you serious?  I was sure I saw displacement before.  I'll finish this post then go find the example I'm thinking of.  Meanwhile here's a current test on scale 1-meter cubes:

[gregsandor]

Okay -- here are two renders of the same model.  It is raytraced and all the detail in the panels is displaced, unless that is an expecially convincing bumpmap.  Looking at the far corners it does appear to be flat, but the shadows on the near corners look right.  Now I'm confused.

[old_blaggard]

Yup, that looks like bumping to me. Note how flat it is on the 90-degree angle just left of the curved corner.

[gregsandor]

Yeah, you're right.  I've just found the posts I missed about this new "feature."  Wish I'd read them before noon today when I started writing these shaders and spent the afternoon tearing them apart trying to fix the displacement. 

[Henry Blewer]

I build in the displacements now. Bump mapping works well when the light strikes across it at the right angle.

[reck]

It's a shame this limitation exists. Can it be something that can be added in future?

I always used to add a bit of displacement in TG to add a bit of realism to the objects. Now I have to compromise between using raytracing but having no displacements or having displacements but no raytracing. Can't I have it all 

[Henry Blewer]

I think Matt will be bringing the object displacement back. They rushed the last release for us to have at Christmas. I was very glad they worked so hard to get it out then.

[Klas]

I don't think that this can be done easily with the raytracer. The mesh must be subdivided first which results in a horrible amount of data. I have tested this with the dragon and blender (here) and it brings the object file from 10MB to 175MB. I have used a subdiv level of 2 for the main parts and 3 on some small parts of the object, not all parts are subdivided. The map is also as bump map on the dragon.

[Henry Blewer]

Maybe there will be a switch (checkbox) to change the render type for objects.

[dandelO]

Not just displacement is affected, high/low mixing of colours of fractals don't show in the raytracer, you get a flat, single tone colour.

I think that I read that it's to be addressed for the next release.

[gregsandor]

Matt, please restore the displacement for models in the next update.

[Oshyan]

It's not likely that a fix for this will make it into the next update, but we certainly intend to address it in the future. What may come first is the ability to select which objects/populations are raytraced and which are rendered traditionally. This would allow you to specify a foreground object to use the normal renderer so it could have displacement, for example.

- Oshyan

[reck]

I think that's a good workaround until displacement is brought back.