Setting up vertex blending with parallax as well?

jordank95

I've set up vertex blending for one of my materials and it works fine. Here is the setup:



Now I have this Parallax setup, and Im not sure how to connect it to the above material graph:



any help how to improve this and make this work would be awesome. I can't seem to find anything in UE4 help or anywhere else.

Thanks guys

EDIT: Interesting. I realize something might be broken with version 4.20 and vertex painting. Seems other people are having this same issue. When I apply this material to my mesh, the whole thing has a red tint to it. The only way to get rid of the red is to paint it off using the Colors tab in the Paint tool. Then I switch to Weight and vertex paint like usual. OR if I just disconnect the RGB from the vertex color node, everything works as it should. Does that seem correct?

Obscura

In this case you would need 2 parallax functions, one for the bottom and one for the top material. Then just connect the output uvs to your bottom and top uv inputs. But this would  be a very expensive material overall. Depending on the target hardware, I would most likely advice to avoid this.

jordank95

Obscura said:

In this case you would need 2 parallax functions, one for the bottom and one for the top material. Then just connect the output uvs to your bottom and top uv inputs. But this would  be a very expensive material overall. Depending on the target hardware, I would most likely advice to avoid this.

Hmm, ok thanks. When is a good time to use parallax in a material then? I was going to use this for the stone walls to give them more depth. 

Zablorg

I've never heard of using parallax cheats for something stone walls- I guess if normal maps aren't selling the depth enough, could you consider making the desired depth of the wall reflected in the model itself?

Consider the tradeoff between a more expensive model and a more expensive shader, I guess. I'm told model complexity is pretty trivial for hardware to handle these days.

jordank95

@Zablorg @Obscura thanks for the info. Though I guess Im still confused as to when to use height maps with tessellation or parallax? Some examples would be great. Thanks for the help guys.

Obscura

I would say for a performant approach, just use a chain of bump offsets.... Look up iterative parallax using bump offset. That lets you have fairly good looking parallax for way cheaper than standard pom/relief mapping with some tradeoffs.

jordank95

Obscura said:

I would say for a performant approach, just use a chain of bump offsets.... Look up iterative parallax using bump offset. That lets you have fairly good looking parallax for way cheaper than standard pom/relief mapping with some tradeoffs.

I guess my question really is more basic than that. I see people creating Height maps for materials in Designer. Are height maps with tessellation really only used on terrain or something else?

Obscura

Check out bump offset. Its a cheaper version of parallax. When multiple of them hooked up into each other, it can look very close to pom, and its cheaper. 

In games, heightmaps with tessellation is usually only used on terrains, yes. There are some rare examples of using it elsewhere though, on ultra high graphics settings.

Zablorg

Materials have a pixel depth offset node, but I haven't read much about its application. I suppose here would be a good place to ask- is it something one should always be inputting whenever possible with a height map? Does its use enhance parallax methods such as bump-offset, or does it conflict with them?

Obscura

Pixel depth offset can be used to make nice intersection between meshes with parallax materials. Check out the content examples, they show this too. This is what it would look like:


However, it adds a lot of shader complexity! It also badly works with baked shadows. The offset wouldn't be taken into account on the intersecting mesh, when the light gets baked.