Using Blocks with VRay doesn't seem to work

[brandonlynne]

Basic workflow question. I'd like to be able to have models in external files and place instances in a render scene. This would be helpful b/c the design is changing, and if I want to change the KB on the phone in my scene, it's basically impossible to get the revised KB back into the right place once I've staged the scene (especially since Rhino doesn't support pivot points like other 3d programs so getting objects into the same position is awful).

But, there is a catch. VRay doesn't seem to apply materials to blocks! When I import the block, all of the layers are imported, and I can assign materials to each layer (representing each part), but even with materials assigned to layers, the block just renders white. The only way to get the block to render is to explode the part (which removes the linking of the instance which is the point of the exercise).

Does anyone have a workaround? The parts are complicated and revising the 3d, bringing in the whole product, re positioning, and reassigning the materials is a tedious.

[dkendig]

Re: Using Blocks with VRay doesn't seem to work

just to confirm, blocks don't work with our product, you are correct.

[**dubs**]

Re: Using Blocks with VRay doesn't seem to work

I'm having a little trouble understanding your question.

Using blocks is one way I to import a model for reference. I often use this to have dimensional references to other products and core technology (like a motor or a PCB) so I can build around it.

I don't think it's possible to use them for rendering. . .

You want to import a model, assign materials, and position it in the scene without the Rhino file size getting too large?? If this is the case then I would be tempted to convert it to meshes and manage the polygon count in the mesh to give you the right detail/distance from the camera balance then import that instead? you could assign the materials before you imported it, and even group it. Then it would behave just like a block instance as a mesh and allow you to position it in the same way?

Just a suggestion, maybe someone else has a better one. . .

[frip51]

Re: Using Blocks with VRay doesn't seem to work

Folks,
we've had this discussion earlier over here.
This is a Rhino bug, which hasn't been solved so far.

To make it short, you've got two options: either you update the mapping (block edit, select object, edit mapping, cancel block edit), or you use a workaround (extract rendermesh in original object, export as .obj, re-import and apply material --- insert as block).

Hope that helps,


Cheers,
Matt

[Micha_cg]

Re: Using Blocks with VRay doesn't seem to work

You can assign the materials in the external block file. I name the materials of the block like b.plastic, b.wood ... . If the block is loaded, than you can edit the materials too, but be careful, that you don't overwrite the material at the next block load. Better you keep the materials at the block up-to-date.

Matthias post you the link to the block-mapping-problem thread.

[ozanb]

Re: Using Blocks with VRay doesn't seem to work

block instances are troublesome for material change

[brandonlynne]

Re: Using Blocks with VRay doesn't seem to work

Basically this is a workflow question. I understand that Blocks are broken, but I wondered if anyone else has a work-around.

Just as an example, I work at a design firm. If we're designing a phone, and I want to render, I create a scene, import the model and position it, take an hour to assign all of the materials, and hit render. Two days later we've updated the screen and top bezel, and now I'm forced to start from scratch with the model b/c it's been posed in the scene, and Rhino doesn't support model pivot/centers, so I can't easily re-import the model in exactly the same position. My materials get blown out too, so they have to be manually reassigned, which takes that same hour. Importing instances instead of geometry would let be simply reload the instance, and all the new surfaces would be assigned and in the right place. Memory isn't really the issue, just time.

Is there another way to bring models into a scene in the same position that I'm not unaware of? Mapping materials to layers begins to solve some of the problems. This is now likely a Rhino question instead of a VRay question, but you guys would know better than most.

[LeoBonilla]

Re: Using Blocks with VRay doesn't seem to work

have you ever used Insert instead of import?

[Micha_cg]

Re: Using Blocks with VRay doesn't seem to work

If the block is loaded, than you can edit the materials too....

. .. there is a bug: if only the texture is changed, than the old texture is used. It helps to change the texture multiplier a little bit (1.01 instead 1) and the new texture is used.

[fooprobe]

Re: Using Blocks with VRay doesn't seem to work

Re: positioning, why don't you just make your own reference pivot using, say, three lines. You only need two but it may help to distinguish x from y. Use it in each of your product models, so if you need to replace one with another you can just use the Orient3pt command. 6 clicks. And the lines don't render so you don't even need to hide them.