There we go, problem solved :) Good stuff Alex. I guess for more complex cases, you've got RGBA values to store your x/y offsets and scales. You'd just have to watch the accuracy - are the gl_Color values 8 bit?
It could get nasty if you're using a few large textures, or if you're using a bunch of animated image sources though. If that's the case, try my approach, otherwise stick with Alex's image dictionary. Chris On 17 March 2010 13:01, Alex Drinkwater <[email protected]> wrote: > OK, this works. > > There's a GLSL shader with 4x Sprite patches inside it. > Each Sprite has a different value for the Red channel of it's Color input. > The Red channel is read in the Vertex Shader from gl_Color. That value is > used to offset the texture coordinates on the X-axis. > I also had to scale the X-axis texture coordinates so that they only covered > 1/4 of the width of the texture (since it was a strip of 4 different > graphics in a horizontal row). The logic would be a bit more complex for a > sheet of different textures arranged in a grid, rather than a strip, but the > principle would be the same, except you'd need to scale and offset on both > X and Y axes. > > > > alx > > > > > > > > On 17 Mar 2010, at 10:06, Chris Wood wrote: > >> Just to be clear, you can have one shader applied to multiple objects >> but it will apply the same texture/effect/whatever to every object. >> Fine if you want say lighting applied to everything, but not if you >> want separate textures. >> >> One solution: give each object a unique colour, and use the colour to >> select a texture from an array by index. >> >> Chris >> >> On 17 March 2010 09:51, thomas pachoud <[email protected]> wrote: >>> >>> Hi, >>> not 100% sure, but I don't think you can use one single GLSL for multiple >>> objects. You should use one GLSL applied to each objects. In this way, >>> each >>> objects will apply the same GLSL with his textures and 3D positionning >>> and >>> lighting information. And if you need to act on full scene, you should >>> add >>> one GLSL at the end of your pipeline, playing on your 2D final rendering. >>> On Tue, Mar 16, 2010 at 9:35 AM, George Toledo <[email protected]> >>> wrote: >>>> >>>> I may be wrong, but I don't believe that is possible in QC. What you >>>> would >>>> need to do is use a separate shader for each object. GLSL in QC does >>>> support >>>> multiple textures, but I don't think one can assign them to arbitrary >>>> objects in the scene. >>>> I'm curious about this as well... I've successfully used GLSL in QC to >>>> send many different image sources to a shader, and to use the shader to >>>> crop, translate and dissolve, but that is in the context of a 2D >>>> surface. >>>> Is there a downside to putting each object in a separate GLSL macro, and >>>> using distinct textures for each in your scenario? You can always >>>> connect >>>> the join the lighting of each (or any other parameter) with insert >>>> splitters, so your multiple shaders can look cohesive in the scene when >>>> you >>>> move a light source (or whatever). >>>> -George Toledo >>>> >>>> On Mon, Mar 15, 2010 at 7:11 AM, luca palmili <[email protected]> >>>> wrote: >>>>> >>>>> Hi to all, >>>>> my scene is composed by N objects (o1, o2..., oN), each of them has got >>>>> one different texture (t1, t2, ..., tN). How can I render all the >>>>> objects in >>>>> a single GLSL shader? I mean: if I pass my N texture as uniform >>>>> parameters >>>>> to the GLSL shader, how can I tell to the GLSL shader to use texture_1 >>>>> for >>>>> object_1, texture_2 for object_2, etc...? >>>>> Thank you! >>>>> >>>>> _______________________________________________ >>>>> Do not post admin requests to the list. They will be ignored. >>>>> Quartzcomposer-dev mailing list >>>>> ([email protected]) >>>>> Help/Unsubscribe/Update your Subscription: >>>>> >>>>> >>>>> http://lists.apple.com/mailman/options/quartzcomposer-dev/gtoledo3%40gmail.com >>>>> >>>>> This email sent to [email protected] >>>> >>>> >>>> _______________________________________________ >>>> Do not post admin requests to the list. They will be ignored. >>>> Quartzcomposer-dev mailing list >>>> ([email protected]) >>>> Help/Unsubscribe/Update your Subscription: >>>> >>>> >>>> http://lists.apple.com/mailman/options/quartzcomposer-dev/thomas.pachoud%40gmail.com >>>> >>>> This email sent to [email protected] >>> >>> >>> >>> -- >>> Thomas Pachoud >>> ingénieur multimédia IMAC >>> www.creapach.fr >>> >>> _______________________________________________ >>> Do not post admin requests to the list. They will be ignored. >>> Quartzcomposer-dev mailing list ([email protected]) >>> Help/Unsubscribe/Update your Subscription: >>> >>> http://lists.apple.com/mailman/options/quartzcomposer-dev/psonice%40gmail.com >>> >>> This email sent to [email protected] >>> >> _______________________________________________ >> Do not post admin requests to the list. They will be ignored. >> Quartzcomposer-dev mailing list ([email protected]) >> Help/Unsubscribe/Update your Subscription: >> >> http://lists.apple.com/mailman/options/quartzcomposer-dev/the_voder%40yahoo.co.uk >> >> This email sent to [email protected] > > > _______________________________________________ Do not post admin requests to the list. They will be ignored. Quartzcomposer-dev mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/quartzcomposer-dev/archive%40mail-archive.com This email sent to [email protected]
